Visual Thermometer – Circuit Playground Express

Visual Thermometer

This project uses the Circuit Playground Express to create a visual thermometer. The current temperature is measured and represented with LEDS.

Using Circuit Playground Express is a great way to start programming a microcontroller and components. The Playground Express contains components on one small board; including 10 NeoPixels, motion sensor, temperature sensor, light sensor, sound sensor, mini speaker, pushbuttons, slide switch, infrared receiver/transmitter, and capacitive touchpads. Without wiring and soldering, you can write programs that interact with one or all of these components.

Adafruit Circuit Playground Express

This project uses the temperature sensor and all ten RGB LEDs (aka NeoPixels), Every ten seconds, a temperature reading is taken and represented by lighting the LEDs. First, the tens are displayed in blue followed by the ones in yellow. 79 degrees Fahrenheit is displayed as seven blue lights, followed by nine yellow lights.

Circuit Playground temperature senors and ten RGB LEDs
Displaying 79 degrees

The Code

The current version of this code is available on Github.

# Import Libraries
import board
import time
from adafruit_circuitplayground.express import cpx

# LED Settings
cpx.pixels.brightness = 0.2
cpx.pixels.auto_write = True
RED = (255,0,0)
NONE = (0,0,0)
BLUE = (0,0,255)
YELLOW = (255,255,0)

# Defaults
led_degree_delay = .1  # Seconds between LED degree display
led_tens_delay = 2. # Seconds between display tens and ones of temperature
measurement_delay = 10  # Seconds between temperature measurements

# led_temp - display temperature with LEDS.  First tens, and ones.
def led_temp (temp_f):
    # Light an LED for each 10th dgree of temp, 72 degrees has 7 LEDs
    tens = int(abs(temp_f // 10)) * 10
    ones = int(abs(temp_f)) - tens
    cpx.pixels.fill(NONE)
    print("Update LEDs display")
    # Display tens
    for x in range(tens / 10):
        cpx.pixels[x] = BLUE
        time.sleep(led_degree_delay)
    time.sleep(led_tens_delay)
    cpx.pixels.fill(NONE)
    # Display ones
    for x in range(ones):
        cpx.pixels[x] = YELLOW
        time.sleep(led_degree_delay)
    time.sleep(led_tens_delay)
    cpx.pixels.fill(NONE)

while True:
    # Take temperature measurement and convert for fahrenheit
    temperature_f = cpx.temperature * 1.8 + 32
    print(temperature_f)
    led_temp(temperature_f)
    time.sleep(measurement_delay)

Temperature Sensor

From the Circuit Playground Express datasheet, “There is an NTC thermistor (Murata NCP15XH103F03RC) that we use for temperature sensing. While it isn’t an all-in-one temperature sensor, with linear output, it’s easy to calculate the temperature based on the analog voltage on analog pin#A9. There’s a 10K resistor connected to it as a pull-down.”

Based on my testing, the starting temperature is not accurate, but the changes to temperature are. This project is not about getting an accurate room temperature, it’s about interacting with the components.

Increasing the temperature with a hair dryer, new reading every ten seconds

UPDATE 5/2/2021

After writing this post I continued testing with an additional temperature sensor, the AS2302. I connected it to the Playground Express and updated the to program take an additional reading from the AS2303. The reading was about 3 degrees lower than the Playground’s onboard sensor. It took about ten minutes for the AS2303 to settle in, it’s initial readings were five degrees higher.

AM23002 Digital Temperature and Humidity sensor.

Updated output including both temperature readings:

Temp: 74.8 F, DHT22 71.8 F
Update LEDs display
Temp: 74.8 F, DHT22 71.8 F
Update LEDs display
Temp: 74.8 F, DHT22 71.8 F
Update LEDs display

Updated Program

# Import Libraries
import board
import time
from adafruit_circuitplayground.express import cpx
# For DHT22 (AM2302)
import adafruit_dht

# LED Settings
cpx.pixels.brightness = 0.2
cpx.pixels.auto_write = True
RED = (255,0,0)
NONE = (0,0,0)
BLUE = (0,0,255)
YELLOW = (255,255,0)

# Defaults
led_degree_delay = .1  # Seconds between LED degree display
led_tens_delay = 2. # Seconds between display tens and ones of temperature
measurement_delay = 10  # Seconds between temperature measurements

# Initial HST22(AM2302) device
dht = adafruit_dht.DHT22(board.A7)

# led_temp - display temperature with LEDS.  First tens, and ones.
def led_temp (temp_f):
    # Light an LED for each 10th dgree of temp, 72 degrees has 7 LEDs
    tens = int(abs(temp_f // 10)) * 10
    ones = int(abs(temp_f)) - tens
    cpx.pixels.fill(NONE)
    print("Update LEDs display")
    # Display tens
    for x in range(tens / 10):
        cpx.pixels[x] = BLUE
        time.sleep(led_degree_delay)
    time.sleep(led_tens_delay)
    cpx.pixels.fill(NONE)
    # Display ones
    for x in range(ones):
        cpx.pixels[x] = YELLOW
        time.sleep(led_degree_delay)
    time.sleep(led_tens_delay)
    cpx.pixels.fill(NONE)

while True:
    # Take temperature measurement and convert for fahrenheit - 1.8 + 32
    temperature_f = cpx.temperature * 1.8 + 32
    # Temp from DHT22 (AM2302)
    dht22_temperature_f = dht.temperature * 1.8 + 32
    # print(temperature_f)
    print("Temp: {:.1f} F, DHT22 {:.1f} F".format(
                temperature_f, dht22_temperature_f
            )
    )
    led_temp(temperature_f)
    time.sleep(measurement_delay)

Mouse Shake – A Raspberry Pi Pico and Adafruit Neo Trinkey Project

Pico to Trinkey

In the article, “Raspberry Pi — Expanding My Mind with the GPIO,” I describe my discovery of the Raspberry Pi GPIO and my first project using it. While my second project, Mouse Shake, is a small step forward in complexity, I use it daily. It’s exciting to make something useful.

This article reviews the Mouse Shaking program and its journey from a Raspberry Pi Pico on a breadboard to an Adafruit Neo Trinkey.

Mouse Shake is Raspberry Pi used as a USB mouse that continuously moves the cursor on a computer screen. It’s used to keep my computer from sleeping. One of the computers I use daily is a locked-down Windows PC; I cannot change any of its settings. For security reasons, the PC locks and requires a password after a few minutes of inactivity. In an office environment, this functionality makes sense, but for a remote worker, this is a nuisance. I discussed my frustration with the helpdesk and their recommendation was to run a short video looping all day to prevent the PC from locking. Mouse Shake is a better solution.

Mouse Shake – Raspberry Pi Pico

The functionality of Mouse Shake is straightforward. Pressing a button will trigger the cursor to move back and forth and illuminate an LED. A second button press will stop cursor movement and turn off the LED. Curson movement will also stop when a time limit is reached.

The idea for Mouse Shake was inspired by a YouTube video from Novaspirit Tech.

Wiring Diagram

Raspberry Pi Pico Mouse Shake Diagram

Parts:

  • Raspberry Pi Pico
  • LED
  • Switch
  • Jumper wires
  • 220 ohm resistor
  • Micro USB to USB cable
Raspberry Pi Pico Mouse Shake Breadboard

Code Highlights

Mouse Shake is written in CircuitPython. The Mouse Shake code for Raspberry Pi Pico is available on Github.

Active State

The button is used to toggle cursor movement on and off. On a button push, the active_state is toggled:

active_state=not active_state

Active State defaults to False. On button press, the value of active_state is set to “not False” which is True. On the next button push, it’s set to “not True”.

Cursor Move

When in Active State, the cursor is moved, and the LED is turned on. Curosor movement is on the X access, which is from right to left. The distance moved is controlled by a variable and defaults to 100 pixels. The time delay between each movement is also controlled by a variable and defaults to half-second.

mouse.move(x=move_distance)
time.sleep(mouse_pause)
mouse.move(x=-1 * move_distance)
time.sleep(mouse_pause)

Time Limit

Cursor movement is not indefinite. max_shake_minutes defines how long Active State will last and defaults to four hours (240 minutes). When Active State is turned on, the current time is saved. In each iteration of the main program loop during Active State, the elapsed time is calculated, (current time – start time). If the elapsed time exceeds max_shake_minutes, Active State is turned off.

if elapsed >= (max_shake_minutes * 60):
     active_state = False
     active_time = 0
     led.value=False

Mouse Shake Demo

From Breadboard to Product

Because I use the Mouse Shake daily, I wanted to progress from a breadboard to a finished project using a case and soldered components. Before this project, my first time soldering was adding pins to the Raspberry Pi Pico.

First soldering -Raspberry Pi Pico pins

I purchased an Illuminated Red Momentary Pushbutton but couldn’t find an enclosure to hold it and the Pi Pico. After looking around the house I found a pill bottle. While it appeared to be a good solution, it didn’t work well. The Pi Pico and button fit well into the pill bottle and cap, but I didn’t plan for the USB cable. As a result, the pill bottle wouldn’t stand up. Despite my poor soldering job, Mouse Shake did work, lying on its side.

Soldering the Pi Pico
Attaching the button
Completed product

Raspberry Pi Gateway

While tinkering with the Raspberry Pi GPIO and physical programming over the past month, I discovered the “maker space” is large with many products and vendors. I found Adafruit while searching for a LED button.

Adafruit was founded in 2005 by MIT engineer, Limor “Ladyada” Fried. Her goal was to create the best place online for learning electronics and making the best-designed products for makers of all ages and skill levels.”

Adafruit About Us

Adafruit designs and sells boards and components. They have a large selection of microcontrollers of all sizes and capabilities. They are also an excellent resource for learning through their website content and YouTube channel. Sparkfun is the next company on my list to explore.

The Raspberry Pi Pico was my gateway to the larger microcontroller world.

Adafruit Neo Trinkey

Adafruit recently released the Neo Trinkey, a small USB board with two touch sensors, four RGB LEDs, and an ATSAMD21 microcontroller. The Trinkey caught my attention as a possible hardware solution for my Mouse Shake application. It’s a perfect size and has enough power to handle the needs of Mouse Shake. At $6.95 it was worth a try.

Adafruit Neo Trinkey

CircuitPython supports both the Raspberry Pi Pico and Neo Trinkey, as well as two 198 other boards. With some minor changes, I expected the Mouse Shake program created for the Pi Pico would run on the Neo Trinkey. I needed to update the program to accommodate different components. Two touchpads replaced the switch, and four RGB LEDs replace the single LED.

Component mapping.

Code Changes

The Mouse Shake code for Adafruit Neo Trinkey is available on Github. I started with the Pi Pico code and modified it for the Neo Trinkey.

Pins

First step, find out which pins I have access to using the dir() command.

Neo Trinkey Pins: 3

import board
dir(board)
['NEOPIXEL', 'TOUCH1', 'TOUCH2']

Raspberry Pi Pico Pins: 30+

import board
dir(board)
['__class__', 'A0', 'A1', 'A2', 'A3', 'GP0', 'GP1', 'GP10', 'GP11', 'GP12', 'GP13', 'GP14', 'GP15', 'GP16', 'GP17', 'GP18', 'GP19', 'GP2', 'GP20', 'GP21', 'GP22', 'GP25', 'GP26', 'GP26_A0', 'GP27', 'GP27_A1', 'GP28', 'GP28_A2', 'GP3', 'GP4', 'GP5', 'GP6', 'GP7', 'GP8', 'GP9', 'LED', 'SMPS_MODE', 'VOLTAGE_MONITOR']

Touch Pads and RGB LEDs

As my first experience with conductive touch pads and RGB LED, I needed to learn how to use them in CircuitPython. With help from CircuitPython documentation, I wrote a program that activated the LEDs by touch. There are three touch points, Touch 1, Touch 2, and both at the same time. My test program lights up all four LEDs based on these patterns. Touch 1 – Red, Touch 2 – Blue, and both yellow. This test program for Neo Trinkey is available on Github.

Neo Trinky Test

Button to Touch Pad

The code below shows the different between using a button and touch pads with CircuitPython.

Button:

# Import library
import digitalio
...
button = digitalio.DigitalInOut(board.GP13)
button.switch_to_input(pull=digitalio.Pull.DOWN)
...
while True:
    # When button pushed
    if button.value:

Touch Pads:

# Import library
import touchio
...
# Initialize touch pad
touch_pad_1 = board.TOUCH1
touch_pad_2 = board.TOUCH2
touch1 = touchio.TouchIn(touch_pad_1)
touch2 = touchio.TouchIn(touch_pad_2)
...
while True:
    # When either pad is touched
    if touch1.value or touch2.value:
        active_state = not active_state

LED to RGB LEDs

The code below shows the difference between using LED and RGB LED with CircuitPython.

LED:

#Import library
import digitalio
...
#Initialize LED
led = digitalio.DigitalInOut(board.GP14)
led.direction = digitalio.Direction.OUTPUT
...
# Initial LED state
led.value = False

RGB LEDs:

# Import library
import neopixel
# Intialize LEDs
pixels = neopixel.NeoPixel(board.NEOPIXEL, 4,auto_write=True)
pixels.brightness = .1

RED = (255,0,0)
NONE = (0,0,0)
BLUE = (0,0,255)
YELLOW = (255,255,0)

# Initial LEDs state
pixels.fill(NONE)

Int vs Long Int

I had one problem moving Mouse Shake from the Pi Pico to Neo Trinkey. There was something wrong with the code, but Thonny, the Python IDE I was using, did not display a helpful error message. Then I tried running the code in MU, a different Python IDE, and found the error related to “long int type not supported”.

A key difference between the Pi Pico and Neo Trinkey is the processor. Pi Pico has a RP2040 chip (32-bit Dual ARM Cortex-M0+ @ 133MHz), while the Neo Trinkey has a SAMD21 (32-bit Cortex M0+ @ 48 MHz ). The SAMD21 does not support Long Int data types, but it does support Int data types.

The time.time() function used to track elapsed time returns a Long Int data type; therefore, the line of code: active_time = time.time() failed execution on the Neo Trinkey. I discovered the time.monotonic() function returns a smaller integer and provides the same functionality. Updating the code to use time.monotonic()corrected the issue. According to the CircuitPython documentation, Long Int data types are not supported at all. More research is required by me to understand why Integers work differently between the two boards.

Mass Storage Device

When connecting a microcontroller running CurcuitPython to a USB port, the computer recognizes it as a mass storage device (USB drive). Having the board connected as a USB drive is helpful when programming because you can easily edit the code directly on the device. For my Mouse Shake project, I don’t want the microcontroller recognized as a USB drive; it should be an input device only. While CircuitPython defaults “mass device storage” set on by default, it can be changed. This change requires rebuilding CircuitPython. It was surprisingly easy to do with the help from an Adafruit tutorial. The CircuitPython USB device defaults are also documented at AdaFruit.com.

In Conclusion

This was a fun and educational project. I’m happily using Mouse Shake daily on the Neo Trinkey. I plan to use the RGB LEDs more effectively:

  • Active – All four LEDs solid blue
  • 5% Active time remaining – All four LEDs solid yellow
  • 1% Active time remaining – Circular motion of RED LEDs

Raspberry Pi — Expanding My Mind with the GPIO

Raspberry Pi Board

I love technology and tinkering with it. After fifteen years of being a devout Apple fanboy, I switched to Linux. While there were many reasons for this significant change, at the core, it was about learning. Since the switch, I’ve learned more about how computers work, both the hardware and software. I’ve built a desktop computer and breathed new life into older computers with Linux. My recent acquisition of the Raspberry Pi 400 started me on a new journey learning physical computing.

Since the Raspberry Pi 3 release in 2016, I’ve been using Pis for single-purpose servers. I’ve set up a network print server, Home Assistant server (home automation), Plex server (media server, mostly for streaming home videos), and a Pi-Hole (network ad blocker and DNS server). I once set up a cluster of Raspberry Pis to emulate a high availability web hosting environment.

Raspberry Pi rack.

As a career software developer, with most of that experience building websites, I’m comfortable writing programs that humans use to interface with information. I’ve also interfaced with software systems to share data, but I have never written software to interface with the physical world; lights, sensors, and devices.

Enter the Raspberry Pi GPIO.

This article is an overview of the things I’m learning in my first experiences with physical computing.

GPIO

The General Purpose Input/Output (GPIO) header on the Raspberry Pi allows you to interface with the physical world. The GPIO has 40 pins used for input and output. Four pins provide power (3v3 and 5v), eight are ground, twenty-six GPIO, and two for advanced use, which does not apply to me yet.

Pi 400 GPIO — Image source: Magpi Magazine

Getting Started

In addition to a Raspberry Pi, you need a few more things to get started with physical computing.

Breadboard —A breadboard, also know as a solderless breadboard, allows you to connect electronic components without soldering.

Full size breadboard

Components — There are many components you can interface with, including LEDs, temperature sensors, moisture sensors, motors, and switches.

Miscellaneous components

Cobbler — A cobbler connects the GPIO header directly to the breadboard, eliminating the need to connect jumper wires directly to the GPIO. A cobbler is not required, but it makes wiring easier — more about this below.

Cobbler

Starter Kits — You can find starter kits online as low as $10USD. The larger your budget, the more components you will get. I recommend choosing a kit that includes a full-size breadboard and Raspberry Pi cobbler.

Starter kit with full-size breadboard and cobbler ~ $28 USD.

First Project — Step 1

While I was lucky to have access to a Personal Computer relatively early in my life (1979 — Heathkit H-88), I never touched electronics, and if I did, it wasn’t memorable and didn’t stick with me. Now, in my fifties, I’m learning basic electronics. The photo below shows a breadboard with a yellow and red LED, two resisters, and a power supply module. While it’s easy to get the LEDs to illuminate, it’s challenging to understand how and why it works. this is what I learned:

  • Series and Parallel Circuits — In a series, components are connected in a chain. “If one goes out, they all go out.” In a parallel configuration, there is more than one path for an electrical flow.
  • Resisters — Resisters are Pi 400needed to limit the amount of current going to a component.
  • Ohms Law — Ohms Law is a formula used to calculate the relationship between voltage, current, and resistance in an electrical circuit
First LED project on a breadboard.

The LEDs illuminated when the power turned on. While this project is simple, it is exciting to see the LED come alive. My wife wasn’t so impressed when I proudly presented the yellow and red lights I had been working on for hours.

As I learned some electronic basics, I’ve only scratched the surface. I’m still trying to get my head around some of the basic concepts.

First Project — Step 2

After understanding how this circuit works, the next step was to replace the power module with the Raspberry Pi 400. I didn’t want to get cocky about my new found skills, so I simplified my project using only one LED. The GPIO has three pins that provide power and eight ground pins. I wired one of the power pins to the positive rail on the breadboard and the ground pin to the negative rail. The LED lit, as expected — another win!

Breadboard wired directly to GPIO.

Since I use the Pi 400 as an everyday computer, having the breadboard wired directly to the Pi 400 is not convenient. This is where the cobbler comes in. It’s connected to the Pi via a ribbon cable, then all of the wires are on the breadboard. It’s easy to remove the ribbon and put the project aside.

Cobbler replaces direct wiring.

First Project — Final Step 3

At this point, the LED is continuously on. My goal is to control the LED with software. The only wiring change required is moving the positive wire from the power pin to a GPIO pin; I chose GPIO 21. The next step is to write a Python program to turn GPIO 21 on and off, making the LED blink.

As I mentioned earlier, the software side is my comfort zone, but this was my first Python program and first time accessing the Pi GPIO. I’m impressed with how Raspberry Pi Foundation has made this easily accessible for people of all skill levels. There are many resources available to step you through a Pi project, from physical books to videos and blog posts.

I chose a tutorial on RaspberryPi.org and used the Thonny IDE to write and execute Python. After a few lines of code, the LED was blinking.

Thonny — Thonny is a Python IDE for beginners provided with Python 3.7. It’s is available from the Programming menu in Raspberry Pi OS. An IDE, Integrated Development Environment, is an editor that makes programming easier. It’s a good place to start with Python.

Thonny and my first Python program.
Yes — it blinks.

Next Projects

The starter kit I purchased came with several components. I’ve had fun experimenting with them. I was also lucky to get my hands on the new Raspberry Pi Pico, the new flexible $4 microcontroller board. I’m going to continue learning through some of the typical Raspberry Pi projects that build your skills and then take on a more significant project.

LCD controlled by Pi 400.
Raspberry Pi Pico.

Pi 400

While I’m using the Raspberry Pi 400, everything covered in this article can be accomplished with previous generations of the Raspberry Pi. The form factor of the Pi 400, as a complete personal computer, allows you to use the Pi as a computer and maker tool at the same time. It’s an excellent way to approach the Raspberry Pi for a non-techie.

Resources

The books and magazines produced by the Raspberry Pi Foundation are available for free in digital format. The physical books are high quality, loaded with information, and well worth the price.

Official Raspberry Pi Guides

Final Thoughts

Over the years, I haven’t spent much time on hobbies. With a mindset of ‘not wasting time,’ I’ve focused my time on activities that forward my career and have an end goal. One gift of the global pandemic is time. The quarantine kept us home with more free time than in the past. In my home, the amount of time we watched TV dropped. We started playing more games, reading, and other activities.

The Raspberry Pi 400 and GPIO has given me an avenue to expand my mind and start a new hobby in a subject area that interests me. I’m not going to be an electrical engineer, but I’ve learned it’s okay to do something because it’s interesting and fun.

The Raspberry Pi Foundation makes learning affordable, fun, and accessible for all ages.


Originally posted on Medium – https://medium.com/linuxforeveryone/raspberry-pi-expanding-my-mind-with-the-gpio-ffece43600ba?source=friends_link&sk=0b171299b27bf85120262128cb6a981a

Is The Raspberry Pi 400 Really A ‘Complete’ Personal Computer?

Raspberry Pi400

When the Raspberry Pi Foundation announced the release of the Pi 400, the company described it as “a complete personal computer, built into a compact keyboard.” This is a bold statement from a company selling project-based single board computers since the first Raspberry Pi release in 2012.

To me, “complete” means including everything needed, hardware and software, to use the Pi 400 as an everyday computer. Let’s explore the Pi 400 as a complete personal computer.

My first Raspberry Pi was a Pi 3, and I use them for specific purposes, such as a media server, print server, and home automation server. I ordered the Pi 400 on November 13 and received it on November 30. Using it for three weeks now as a desktop computer, I’m impressed with what it can do, and I learned what it does not do so well.

What follows is my review of an ‘out of the box’ Raspberry Pi 400 Personal Computer Kit.

Pi 400 Hardware Basics

The Pi 400 is described as a Pi 4 inside of a keyboard. While that is not technically true, the Pi 400 has mostly the same components as a Pi 4 in a different form factor. More importantly, it has the components you would expect in a personal computer.

  • CPU/GPU — 64-bit quad-core ARM (Cortex-A72 at 1.5ghz), VideoCore (VI at 500MHz)
  • 4 GB RAM (LPDDR4)
  • 3 USB Ports (2 USB 3.0, 1 USB 2.0)
  • 2 HDMI Ports (mini)
  • Networking — Gigbit Ethernet port, Wifi (dual-band 802.11ac), Bluetooth (5.0).
  • Storage — microSD, up to 512GB.
  • 40-pin GPIO Connector (general purpose input/output)
Ports on the back of the Pi 400.

The Pi 400 is available in two packages:

Raspberry Pi 400 Personal Computer Kit — includes Pi 400 (keyboard and computer), mouse, power supply, HDMI mini cable, microSD with Rasberry OS installed, and Raspberry Pi Beginners Guide (book). With this package, you supply only the monitor (or television). Cost $100 USD.

Source: Raspberry Pi

Raspberry Pi 400 Unit — includes Pi 400 (keyboard and computer) only. With this package, you supply themouse, power supply, HDMI cable, microSD with Raspberry OS. Cost $70 USD.

I purchased the Pi 400 Personal Computer Kit, which is a great value.

Pi 400 Setup

No technical skills required.

Setting up the Pi 400 Personal Computer Kit is easy. After removing all parts from the package, connect the monitor with the supplied HDMI mini cable, mouse, and power cable. The microSD containing the operating system is already in the microSD slot. That’s it!

Upon boot up, a setup screens walk you through a few prompts: location and timezone, password, and wifi connection. The last step, the system update, took twenty minutes for me. The length of time likely depends on how outdated the software is on your microSD.

When the update is complete, you will reboot. Your new PC is ready!

Raspberry OS and MicroSD

The official operating system for the Pi 400 is Raspberry Pi OS, a Linux distribution, which comes pre-installed on a microSD.

The Raspberry Pi OS Desktop is not a modern looking interface, but it’s straight-forward and easy to use. I expect anyone familiar with Windows or Mac OS will not have trouble using Raspberry Pi OS. Other Linux distributions are also available for the Pi 400. With the Pi using microSD as its primary storage, it’s inexpensive and easy to download a few other operating systems to try out. But this review is of Raspberry Pi OS only.

Technical Note: As of this writing, Raspberry Pi OS is 32-bit. I bet you are thinking, “a 32-bit OS can only access 4GB of memory,” and you are correct. Pi Os 32-bit was modified to access all 8GBs of memory, as the Pi 4 has a 8GB option. A 64-bit version of Raspberry Pi OS is available as a beta release. While stress testing will show the 32-bit OS version is not as performant as 64-bit, it’s unlikely you will not notice a difference for everyday use on the Pi 400.

The Pi 400 Computer Kit comes with a 16GB microSD. There is 6GB of free space after installation, which is adequate to get started. A larger microSD, 32GB or 64GB, would be a useful upgrade. You can also boot from a USB drive; details are available at RaspberryPi.org.

Software

Raspberry Pi 400 comes with dozens of software applications for system management, productivity, programming, and gaming out of the box. They provide a good representation of the Pi 400 capabilities, such as LibreOffice, Scratch, Python, and Mindcraft.

Thanks to the evolution of web browser capabilities and browser-based services, a well-functioning browser checks the box for many personal computing needs, such as browsing the Internet, Facebook (and other social media), Youtube, and e-mail.

Pi OS provides a utility to add software from a repository of hundreds, or maybe thousands of applications. The user interface is not very friendly, and it is challenging to find the software unless you know the application’s exact name, but it works.

Streaming Services — Out of the box, Chromium browser does not support DRM video streaming from services like Netflix, Hulu, and Disney+. With “The Office” leaving Netflix on December 31, 2020, I had a problem. I needed to get as much Michael Scott as possible (That’s what she said). The Pi community has solved this problem, thanks to Veselin at blog.vpetkov.net. With just a few commands in the terminal, a media friendly version of Chromium is added to your menu.

Performance

Performance is important. To call the sub-$100 Pi 400 a “personal computer,” it needs to perform well in that environment. I’ve used the Pi 400 daily for three weeks for common computing tasks. While it’s not as quick as my high-end computers, it performs well. It’s an uncompromising solution for everyday computer tasks.

Jason Evangelho demonstrates the Pi 400’s surprising performance with the video editing in KDenLive on the Linux 4 Everyone YouTube channel.

Connecting During The Pandemic

During the Covid-19 Pandemic of 2020, video calls have become critical in people’s lives with families, friends, teachers, and students all connecting on Zoom, Teams, Meet, and many other platforms.

Zoom is my primary tool. I tried a Zoom client, installed with PiKiss, and Zoom in the browser. Neither approach worked well; in fact, it wasn’t usable on the Pi 400 or Pi 4 (8GB) with Raspberry Pi OS, but I’ve seen others on YouTube having success with Zoom.

Both Facebook Messenger and Google Meet worked well in the browser. I’ll be keeping my eye on the developments in this area.

Sound and Printing

The Pi 400 does not include a 3.5mm audio output jack for speakers, which is available on the Pi 4. Sound can come from a monitor or TV through the HDMI connection, a USB speaker connected through the USB Port, or Bluetooth.

When I received the Pi 400, sound through a USB speaker was not working. In early December, a new version of Pi OS, 5.4, was released and it included Pulse Audio, a sound server. After the upgrade, the sound worked as expected.

The 5.4 release of Pi OS also included CUPS, Common Unix Printing System, to access and manage local and network printers. My LaserJet network printer was recognized and worked without issue.

It’s encouraging that the Raspberry Pi Foundation recognizes ‘must-haves’ for the Pi to become a personal computer and are actively making improvements.

Computer Noise

Because there is no fan or spinning drive, the Pi 400 is silent. Passive cooling keeps the Pi 400 from overheating and throttling the CPU. A keyboard-size heat shield is connected to the top of the CPU with a thermal pad, resulting in heat being dispersed through the shield.

Heat shield inside the Pi 400 keyboard.

Power Consumption

The Raspberry PI is a low powered, single-board computer. Using an Energy-Use Monitor to measure the power usage at the outlet, the Pi 400 uses 2.5 watts at idle. To put “low powered” into perspective, I also measured a few other computers in my house at idle and played a YouTube video in the browser. I’ve included an estimated cost per year at idle (given my utility rates).

Pi 400 (Quad-core ARM, 4 GB RAM)
Idle: 2.5 Watts ($2.28/yr) YouTube: 4.0 Watts

MacBook Air (2020, i3, 8GB RAM)
Idle: 8 Watts ($7.29/yr) YouTube: 10 Watts

System76 Gazelle (i7, 16GB RAM)
Idle: 17.5 Watts ($15.94/yr) YouTube: 28.5 Watts

Rebel Tower (My build, Ryzen 9, 32 GB RAM, AMD GPU)
Idle: 60 Watts ($90.19/yr) YouTube: 94 Watts

For a personal computer, the Pi 400 is very power efficient. As an experiment, I used it for 8.5 hours, watching Netflix, browsing, and writing this article powered by a 10000mAh portable charger.

Pi 400 powered by a portal charger.

Keyboard

The computer is the keyboard. It’s solid and feels good to type on. To me, it’s not the best or worst I’ve used. There’s not much more to say.

Not So Smart: Apple’s Smart keyboard for the iPad is $159, and is pretty dumb compared to the Pi 400!

Help and Documentation

In addition to the “The Official Raspberry Pi Beginner Guide” that comes with Pi 400 Personal Computer Kit, there is a virtual bookshelf full of digital resources available in Pi OS’s Help menu. For example, it contains “Getting Started” guides and every edition of the MagPi magazine. The Raspberry Pi has a large online community with answers to many questions you may have.

Conclusion

Is the Pi 400 a “complete personal computer”? Yes.

Is there is room for improvement? Yes.

With the Raspberry Pi being a project-based computer for most of its life, a consumer-focused desktop interface has not been a priority. While it’s usable, it has a long way to go to compete with mature distributions like Ubuntu. I’m in the process of reviewing alternative OSs and will be sharing my findings. Stay tuned.

While the Pi 4 is available in an 8GB RAM model, the Pi 400 is not. For the purposes of my “daily use” testing, 4GB was enough RAM. I hope to see an 8GB model in the future; the more RAM the better!

Where is the Pi 400 a good fit?

  • A computer for someone that needs day-to-day computing tasks, browsing, writing, e-mail, social media, and casual video streaming.
  • A secondary, or family computer, online access, and homework.
  • The Pi 400 runs on Linux, a great computer to use and learn Linux.
  • While I’m evaluating the Pi 400 as a desktop computer, it’s still a Raspberry Pi, an amazing single-board computer that took the world by storm. Its 40-pin GPIO connector interfaces with additional hardware; such as temperature sensors, LEDs, pulse rate monitors, and much more. The perfect computer for a budding engineer.

The Pi 400 is this generation’s Commodore 64, making computing accessible in a form factor that’s approachable with endless possibilities.


Originally posted on Medium at https://medium.com/linuxforeveryone/is-the-raspberry-pi-400-really-a-complete-pc-3754839ca347?source=friends_link&sk=bf185b953213492b93f8ad2d3cc561b5

Review: Raspberry Pi 400 and Ubuntu Linux 20.10

I recently reviewed the Pi 400 Complete Computer Kit, with its ‘out of the box’ configuration running on Raspberry Pi OS. Now, I’m reviewing an alternative operating system, Ubuntu 20.10, running on the Pi 400.

Ubuntu Desktop, initially released in 2004, may be the most popular Linux desktop distribution in the world. It’s backed by Canonical, a UK-based private company that sells commercial support and services for Ubuntu-based products. Ubuntu comes pre-installed on desktop and laptop computers from various hardware vendors, including System76, Lenovo, and Dell. Ubuntu can also be installed on many other current and legacy computers.

With millions of people using Ubuntu daily, there is no doubt that this world-class operating system could be a good option for Pi 400 desktop users. Let’s find out if it is.

Raspberry Pi and Canonical

The Pi 4, which came to the market in 2019, has hardware components found in a desktop computer, notably a Quad-core CPU, two HDMI ports, Wi-fi, and Bluetooth. Regarding the Pi 4, Martin Wimpress, Desktop Engineering Director at Canonical, said “[there is] plenty of CPU and plenty of RAM, and an upgraded GPU,” and “we really have to start considering the Raspberry Pi Foundation as a PC vendor,” ¹ and they did just that. Teams at Canonical and Raspberry Pi Foundation collaborated to release the first Ubuntu Desktop image on October 22, 2020, for the Pi 4 and Pi 400.

Raspberry Pi is a trademark of the Raspberry Pi Foundation. Ubuntu and Canonical are registered trademarks of Canonical Ltd

Installation

When installing Ubuntu on a Pi 400, start with preparing a microSD. Raspberry Pi Foundation made this easy by providing the Pi Imager application, which prepares a MicroSD, or USB drive, as a boot disk. Pi Imager currently installs two desktop distributions, Raspberry OS (32-bit) and Ubuntu Desktop (64-bit), from a Windows, Mac, or Linux computer. While other third-party desktop distributions are available, such as Manjaro ARM, only Ubuntu is endorsed by Raspberry Pi foundation.

Linux for Everyone’s “Raspberry Pi 400: Install A Different OS The EASY Way” video demonstrates how to use Pi Imager.

With the Ubuntu microSD installed in the Pi 400, the installation is straightforward, prompting for Language, Keyboard, Wifi, Timezone, Username, and Password. Unlike the Raspberry Pi OS, you can set up multiple user accounts, which helps a family computer. Each family member can have separate accounts and application settings.

When the installation is complete, the Pi 400 will reboot. Upon the initial login, you are prompted for account-specific settings: Online Accounts setup (more about this below), an option to send information to Canonical, and enable Location Services.

All systems go!

Look and Feel

Ubuntu uses GNOME for its desktop environment. GNOME describes itself “as an easy and elegant way to use your computer.” I agree. If you are familiar with Windows or Mac OS’s current version, using GNOME will be a comfortable transition.

You will be struck by the default background, which is a gorilla wearing sunglasses. Groovy Gorilla is the code name for Ubuntu 20.10. The next version of Ubuntu 21.04 is Hirsute Hippo.

Groovy Gorilla

Using Appearance Settings, you can set windows to dark mode and move the dock from its default location on the left of the screen to the bottom or right. A bar at the top of the window gives you quick access to wireless/network, sound, and Bluetooth settings.

Software

Ubuntu includes the software applications needed for everyday computing, including a word processor, spreadsheet, web browser, and e-mail program. Canonical has a partnership with Mozilla; therefore, the Firefox web browser and Thunderbird e-mail client are installed.

Since the Pi is an ARM-based computer, there are not yet as many applications as on an X86 computer. But there are hundreds, maybe thousands, to choose from in the Ubuntu Software “store.” It’s unlikely you cannot find an application that fits your needs. All applications are free to install.

Ubuntu Software Store

Gimp and Snap Store

I’ve been using the Pi 400 with Ubuntu 20.10 for daily computing tasks, like e-mail (via browser), YouTube videos, research, and writing this review. This article’s images were modified using Gimp, which could not be installed via the Ubuntu Software store. The software store installs Snap versions of applications, and I received an error during installation.

Gimp install error

I successfully installed the .deb version of Gimp from the command line with the following command: sudo apt install gimp. I don’t know how wide-spread this type of Snap problem is, but I expect it will be corrected in the future.

What is a Snap? Simplified explanation: Snap packages, known as ‘snaps’, are self-contained software packages, meaning all application dependencies are included within the install. On the other hand, .deb files, the traditional packaging for Ubuntu applications, do not include dependencies, and they must be installed separately. If you are using .deb packaging and two applications require different versions of the same dependency, you have problems. Snaps resolve that issue. You can learn more about snaps on the Snapcraft website.

Video and Premium Content

While the Pi 400 is a desktop computer and not a media server, there is a reasonable expectation of watching videos. Premium content from Netflix, Amazon Prime, Disney Plus, Spotify, and others is not available on a Pi 400 with Ubuntu 20.10. This issue is not the fault of the Pi or Ubuntu. These streaming services use the Digital Rights Management (DRM) software WideVine, to prevent non-subscriber access to content. The WideVine software is not available for 64-bit ARM environments, like the Pi 4 and Pi 400. Until WideVine makes these libraries available, DRM content cannot be accessed.

Netflix error.

NOTE: If premium content is a must, you can access Netflix and others on a Pi 400 running Raspberry PiOS (32-bit). WideVine libraries are available for ARM 32-bit that run on older versions of the Chromium browser. Thanks to Veselin at blog.vpetkov.net, with just a few terminal commands, 32-bit WideVine is installed and configured for a special installation of Chromium.

YouTube videos play well in Firefox. 480p and 720p are both usable, with some frames dropped. The lower the resolutions, the better the video experience. 4k video is not usable.

Online Accounts

During the setup process, you are prompted to connect your Online Accounts, including Facebook, Google, Microsoft, Foursquare, and more. The idea behind this feature is to make it easier to connect your online services to applications. For example, after connecting to your Google account, the Calendar application automatically uses your Google calendar. Conceptually, this feature makes sense, but I found the implementation to be disjointed and confusing.

Wait, What? Did I say Foursquare? That’s still a thing? It sure is — with 55 million monthly active users! ²

Online Account Settings

I connected Online Accounts to G-Mail and enabled that connection for Mail, Calendar, Contacts, Documents, Photos, Files, and Printers. I proceeded to open Thunderbird, the default e-mail client, and expected it to load my e-mail, but it didn’t. Thunderbird was ‘not aware’ of my G-Mail account. After some research, I learned that a limited number of applications use Online Accounts, and most are not the default applications installed. It’s misleading and confusing to setup Online Accounts that don’t work with default applications. I tested the 20.10 Ubuntu installation on an Intel computer and had the same problem. This issue is not specific to the Pi 400 implementation of Ubuntu Desktop.

Then, I installed Evolution, an e-mail client that works with Online Accounts. Upon startup, it connected to my G-Mail, which is what I expected. While my e-mail and calendar were working in Evolution, the performance of the Pi 400 had a noticeable decline. I uninstalled Evolution, but performance did not improve until I removed Google from Online Accounts.

The Pi 400 hardware may not be powerful enough for the Online Accounts feature of Ubuntu, and maybe IMAP e-mail clients should be avoided as well.

Technical Details: When Online Accounts were connected to Google, the “evolution-calendar-factory” process used a significant amount of CPU and Memory. This process is part of GNOME and cannot be removed. When Online Accounts are not connected to any services, the evolution processes still run but use minimal resources.

Sound and Printing

Ubuntu 20.10 recognized my HP network printer, connected to it, and printed flawlessly.

The Pi 400 does not have a 3.5mm audio jack; therefore, sound comes from speakers connected through HDMI, USB, or Bluetooth. I attached a USB speaker for testing. By default, Ubuntu 20.10 is configured to use the “Headphones — Built-in Audio” audio output, which does not exist. I had to change the audio output device manually.

Performance

Outside of the issues I found with Online Accounts, Ubuntu 20.10 performs well on the Pi400. I did not benchmark the performance of Ubuntu or Raspberry Pi OS, but used them regularly. Pi OS feels snappier. I know that’s not very technical, but it is a useful measurement. Like I said in my previous review, “While it’s not as quick as my high-end computers, it performs well. It’s an uncompromising solution for everyday computer tasks.”

Conclusion

Ubuntu is a fantastic desktop operating system. While I uncovered a few problem points with Ubuntu 20.10 on a Pi 400, its maturity shines. Keeping in mind that 20.10 was recently released, I expected there would be issues and they will be resolved with time.

Ubuntu 20.10 Desktop for Pi strengths:

  • Mature desktop environment
  • Support for multiple user accounts
  • Vast number of applications available

Ubuntu 20.10 Desktop for Pi weaknesses:

  • No support for premium content providers (Netflix, Amazon Prime…)
  • Just beyond beta — there are clearly issues that need to be worked out.
  • Lack of support for the unique features of the Raspberry Pi. Ubuntu 20.10 does fully support the ‘maker tools’ for interfacing the GPIO (General Purpose Input/Output). See Ubuntu 21.04 below for more details.

“Multi-Boot”

Dual-booting a computer is when it’s configured to run two different operating systems, such as Mac OS and Windows. With the cost of a microSD and ease of loading a new operating system on it, the Pi 400 is a multi-boot system. You can explore different desktop operating systems and use the one that works best for the tasks at hand. Next up for me, Manjaro. Stay tuned!

Ubuntu Desktop 21.04

Ubuntu is planning ¹ the following updates for the April 2021 release:

  • Finalize the GPIO implementation
  • Track and implement the improvements made to the kernel by the Raspberry Pi Foundation
  • (Hopefully) Making a full transition to the full KMS drivers to provide better hardware support.

References

¹ “Ubuntu Desktop on Raspberry Pi” — Rhys Davies, Product Manager Canonical, Martin Wimpress, Engineering Director Ubuntu Desktop. https://www.youtube.com/watch?v=0pT4-RcTERU&t=879s

² “41+ Must Know Foursquare Statistics in 2020” — Denis Metev, https://review42.com/foursquare-statistics/Linux For Everyone

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