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Raspberrry Pi 400, first steps

First steps with the Raspberry Pi 400, first impressions
November 2, 2020. My birthday!
Early, checking twitter. Eben Upton says good morning. The Pihut responds and some tweets about children follow.
I recognize the pattern: if Eben is up this early online, it must be an announcement. And yes, there it is: the new Pi 400!
A Pi 4 in a keyboard, a homage to the home computers of the 80ties, a relief for those who worry about a naked PCB with untidy cabling in a school class, and all that value and performance for a low price!

So I gave myself a present, and ordered the Pi 400 immediately at The Pi Hut. After a week (quite fast this time for UK mail!) it arrives, a small rectangular package. Inside the Pi 400 and a power supply. I ordered the Pi 400 itself, not the package. I have enough cables, mouse etc.. And I do not want to use a SD card.

After installation and configuration, covered below, the fun starts. What a nice little machine! Reminds me of the home computers in the 80ties of previous century, which I tested and wrote so much about then. But in an modern format, with a modern and capable operating system, hardware fast enough for the most tasks, easy to integrate in my home network and systems.
Cool, compact, well protected, a mature operating system, Linux Debian nicely adapted to the Pi 400 and satisfies the needs of a regular user like me, with a Windows 10, Synology NAS and Pi’s network. You can see a lot of thought and work has gone into the design of the Pi 400 and it pays off!

Will it be my main PC? No, not really. That will be the Intel with Windows 10 power for photo and video editing, large software development, ergonomic and excellent Microsoft keyboard and mouse with three large displays,  large fast disks, lots of memory and CPU power.

Will it be my second PC? Yes, there is enough I/O and enough performance for web browsing, mail, media center, software and hardware development for the Pi with e.g.  Lazarus, for the other Pi’s here. With some cheap simple USB and SSD devices it keeps affordable and good enough.

All in all, it has found a place on my desk and in my network, it will be of real value to me!

What I cover here is:
Configuration
Installation to SSD
Audio: USB Audio and fight with Bluetooth
Camera, USB webcam
Overclocking
File Manager, access my Windows and Synology network shares
GPIO connector


Configuration
I opted for the Pi 400, US keyboard, and not the package. I have enough cables and mouses, and plan to skip the SD card completely.

Nicely packaged, online documentation only. Here is the (hard to find!)  Beginner’s Guide, 4th edition pdf download. Well written, recommended for new users. After many years working with Pi’s (since 2012) and keeping up to date with the blog and the forum, I found configuring and setting up the PI 400 quite easy.
As you can see in the photo I added to the Pi 400:
– USB hub into the USB 2 port, four USB ports for the next USB devices
– mouse (any USB mouse will do, I use the Raspberry Pi Mouse)
– USB audio adapter (a cheap one)
– USB webcam (an older simple one)
– HDMI mini to HDMI female  adapter cable to a DVI adapter to  (no HDMI on this Displayport/DVI/VGA)  IIyama monitor!.
– CAT5 Ethernet cable to the GHz network
– USB C power adapter, the official one
– USB-3 Eluteng adapter to SATA 120GB SSD disk (this Eluteng, has ASM IC, works fine)


Installation to SSD, no SD required!
I am not that fond of the SD card as system disk for a computer. Though in the real world it does work fine for most of us, it not designed for heavy computer use, wears out and is not that fast. For embedded usage it is ok, for a desktop a real larger computer hard disk is better. So for the Pi 400 I choose a SSD with an Eluteng USB 3 adapter. USB booting is now working well on the Pi 4 out of the box.

So I took the SSD to my WIndows PC, started the Raspberry PI Imager, choose the “Raspberry Pi OS (32-bit) with desktop” as OS and the SSD as “SD card” (yes, that is supported!).
Writing the image was very fast compared to imaging an SD card!

The SSD was then attached to a USB-3 port of the Pi 400, and power switched on. It took some time, be patient, not too much status messages shown, file system expanded, reboot and then the Raspberry PI OS screen appeared and the usual questions asked. Which HDMI port? It seems not to matter!
The automatic updating/upgrading took quite some time, but after another reboot, the Pi 400 was up and running. Subsequent boots are very fast compared to SD booting!
The SD card reader? Not required for the OS, free to use, with automatic mounting.


Audio, USB Audio and fight with Bluetooth
A desktop PC without audio is not done. The Pi 400 has standard audio via HDMI. Now HDMI monitors may have a loudspeaker, but not high quality.
HDMI to DVI does not support audio. Other PI’s have analog audio out, the PI 400 does not have this, and it is not a real loss, it is of mediocre quality).

 

 

So what options for audio do I have?
– a cheap and good quality USB Audio adapter. That works well, good stereo analog audio to the soundbar on my desk.
– Bluetooth audio. Connecting and pairing to my soundbar Bluetooth succeeded, VLC plays audio fine.

But Chromium refuses to play. Known bug it seems with the current version of Chromium, I read more complaints on the forum. Note that I did not install any additional Bluetooth component, PulseAudio seems to break any chance of audio. Builtin Bluetooth support is enough (but not pleasant to work with, as on all OS’es it seems). Chromium will hopefully be repaired soon.
Here a workaround that lets youtube make sounds, many other websites are still silent. Chromium has serious problems with audio!
Add a script with e.g. nano

nano chromiumaudio.sh

and add these lines:

#!/bin/bash 
chromium-browser --disable-features=AudioServiceOutOfProcess 

Start chromium with audio with

bash chromiumaudio.sh

or create a desktop menu item for this.


Camera, USB webcam
A desktop PC without a webcam is not done, So I searched in my drawers and found an older USB Webcam. Not the best quality, but it shows a normal USB webcam works fine on the Pi 400.

 

 

 

 

 

This requires an additional software install, in a terminal type:

sudo apt install fswebcam.

A simple test with a webcam testpage showed it functions fine. as shown in the photo.


Overclocking
The Pi 400 runs un 1.8GHz and stays cool with that large metal cooling plate.
Overclocking is not really necessary, but some extra is always welcome. And the Pi stays just as cool!
Stay with recommended values not violating warranty:, perform the following in a terminal

sudo nano /boot/config.txt

Change the line with arm_freq to:

arm_freq=2000

Add the line

over_voltage=6

and reboot.


File Manager, access my Windows and Synology network shares
My network is made up of many systems. My main workstation is a power Windows 10 notebook with more screens. Further I ahev many Raspberry Pi’s, ESP8266, ESP32 nodes around. Arduino and propriety media servers, Chromecast. Several security camera’s served by Synology . My main storage is made up of two Synology NAS servers

So I took a look at what the Raspberry Pi OS Filemanager offers, And I was pleasantly surprised with the current state and posiibilities!

First I unleashed the ‘hidden’ things:


Uncheck:
Display simplified user interface and menus
Check
– Filesystem root
– Devices
– Networks
– Volume and Mounts


Now when I click on Networks in the left folderview, I see part of my network, the two Synology NAS systems.

Clicking on the Synology NAS (File Sharing) gives a list of shares on this NAS server (SMB network)

Now the file manager asks for username and password (and workgroup name). It offers to remember those, but most of the time it forgets anyway.
If you make a mistake in name or password, the fields are just cleared, no error appears.

Now you see the folders in the share and can work with the files. Depending on share and user also writing, determined by the NAS admin.


When you choose the Windows Network, nothing is shown but an empty panel and in the top field the text ‘smb:///’. Change smb:/// to smb://<computername>, where <computername> is the name of a Windows PC.
In my case it is smb://asusho


The shares of the Windows PC are now shown, select one and the usual username password form is shown. Fill in a LOCAL user on the Windows PC, which has access to the share you want. The usual Windows username, an email address, does not work. Create if needed a local Windows user and grant access to the share.


If all checks out, you have now access to the share, in this case the data disk of my Windows PC asusho.


GPIO connector
The well known 40 pin GPIO connector is available, on the backside. Now that is not too handy for the many HATs available.

I expect to see some aftermarket solutions for that with cables and cases!

A short 40 pin flatcable female-female, e,g, as supplied with a T-Cobbler makes it easy to connect to a breadboard as seen in the photo.

Note that these 40pin connecters have notches on the top, which fit nicely in the Pi 400 and the T-Cobbler connector. So no mistakes in orientation may be made, as with the other Pi’s.

Itead 2.8 TFT Add-on V2.0 Touch

A small display, again one of those LCD screens attached via SPI. slow refresh, OS support frozen in time.

Instructions that worked for me, April 2020. 

https://www.itead.cc/blog/raspberry-pi-b-2-8-tft-add-on-v2-0-touch-function-realizing


Download Raspbian-2015-02-16.img into SD card, then launch Raspberry Pi B 
Its old Wheezy Debian, unsupported and outdated, so make sure you change to the legacy update, the official repository moved on. But there is a legacy repository!

Replace this line in /etc/apt/sources.list
deb http://legacy.raspbian.org/raspbian/ wheezy main contrib non-free rpi

Now you can do the 

sudo apt-get update

Do the usual raspi_config, add SPI support

sudo nano  /etc/modprobe.d/raspi-blacklist.conf
Comment the mask of spi out
#blacklist spi-bcm2708

Connect Raspberry Pi B+ 2.8 TFT Add-on V2.0 to Raspberry Pi B+ correctly

sudo apt-get install xinput evtest tslib libts-bin

Download the fbtft driver, and you may need to run the following command three times:
sudo REPO_URI=https://github.com/notro/rpi-firmware rpi-update

Finally get the codes:
*** Running pre-install script
Work around rpi-update issue #106
*** Updating firmware
*** Updating kernel modules
*** depmod 3.12.21+
*** Updating VideoCore libraries
*** Using HardFP libraries
*** Updating SDK
*** Running ldconfig
*** Storing current firmware revision
*** Running post-install script
/lib/firmware
*** Deleting downloaded files
*** Syncing changes to disk
*** If no errors appeared, your firmware was successfully updated to b77683205688d3f6ae2b32a3c7
f4e63de1c06a5d
*** A reboot is needed to activate the new firmware

By now,you need to reboot your Raspberry Pi B+
sudo reboot

sudo touch /usr/share/X11/xorg.conf.d/99-fbdev.conf

Configure the file /usr/share/X11/xorg.conf.d/99-fbdev.conf

sudo nano /usr/share/X11/xorg.conf.d/99-fbdev.conf

Section "Device"
  Identifier "itdb28"
  Driver "fbdev"
  Option "fbdev" "/dev/fb1"
EndSection

sudo modprobe fbtft_device name=itdb28 gpios=reset:5,dc:6,wr:12,cs:13,db00:20,db01:21,db02:22,d
b03:23,db04:24,db05:25,db06:26,db07:27 rotate=90 fps=50

Add the following contents to file /boot/config.txt
dtoverlay=ads7846,cs=1,speed=2000000,penirq=17,swapxy=1,xmin=230,xmax=3850,ymin=190,ymax=3850,p
max=255,xohms=100
startx &
 (you may have to reboot)

Load the touch driver
1.Add the following contents to file /boot/config.txt

dtoverlay=ads7846,cs=1,speed=2000000,penirq=17,swapxy=1,xmin=230,xmax=3850,ymin=190,ymax=3850,pmax=255,xohms=100
2.Reboot Raspberry Pi B+

sudo reboot
3.Load TFT display driver

sudo modprobe fbtft_device name=itdb28 gpios=reset:5,dc:6,wr:12,cs:13,db00:20,db01:21,db02:22,db03:23,db04:24,db05:25,db06:26,db07:27 rotate=90 fps=50
4.start up X Server

startx &
Adjust the X&Y directions of this touch screen
DISPLAY=:0 xinput --set-prop 'ADS7846 Touchscreen' 'Evdev Axis Inversion' 0 1
Test
·Check the event’s number which is in accord with the touch screen.

	cat /proc/bus/input/devices

This event’s number here is event3, then you need to execute the following command to do the calibration and test touch screen according to the event’s number you’ve got. When do calibrating, you’d better use touch pen to click the cross’s center unless you want a rough calibration result.

·Touch screen calibration

sudo TSLIB_FBDEVICE=/dev/fb1 TSLIB_TSDEVICE=/dev/input/event3 ts_calibrate

Hyperpixel 3.5 Pimoroni

3.5 inch touch screen. Superseeded by Hyperpixel 4.0

Reasonable quality, touch is, though it i capacitive, not too easy to use. Resistive screens an be handled with pens, not this one.

With current Buster not a perfect pair.

Two experiments:

Raspberry Pi 2 B V1.2 success

1 imaged a SD with current Buster (feb 2020)
2 booted on a Pi 4 1 GB
3 did the usual raspi-config things and update/upgrade
4 checked out the system, works as expected
5 curl https://get.pimoroni.com/hyperpixel | bash
6. rebooted , installed Hyperpixel

Result is a working display, HDMI whosw rainbow screen, touch is wrong, cursor moves opposite directions, axes mixed up.
So not too bad, but touch not configured correctly.

Fixed with, in a console window, the command

$ hyperpixel-rotate normal

which changed the orientation of the screen to what is aleady was, and changed the touch matrix to a working touch.

So far so good.

Raspberry Pi 4 1 GB failure

To check out the Pi4, current Buster (feb 2020) and Hyperpixel 3.5 I did the following:

1 imaged a SD with current Buster (feb 2020)
2 booted on a Pi 4 1 GB
3 did the usual raspi-config things and update/upgrade
4 checked out the system, works as expected
5 curl https://get.pimoroni.com/hyperpixel | bash
6. rebooted , installed Hyperpixel

Result is not a working Hyperpixel display, but reverse image on HDMI, Hyperpixel dead.
Which is the same effect as booting from the working Raspberry Pi 2 SD.
Maybe the curl https://get.pimoroni.com/hyperpixel | bash gets the old hyperpixel install and not the Pi 4 version? Looks like it.

So back to

1 imaged a SD with current Buster (feb 2020)
2 booted on a Pi 4 1 GB
3 did the usual raspi-config things and update/upgrade
4 checked out the system, works as expected
5 downloaded the Hyperpixel Pi 4 git repository
6. rebooted , installed Hyperpixel with ./setup.h

Result is Hyperpixel noise banner, HDMI shows normal screen

So install fails with the curl or setup, and instructions clearly wrong.Issue opened at Pimoroni.

Adafruit PITFT 2.8 resistive


Image Raspbian full if you want a desktop, else lite is sufficient for CLI.

sudo apt-get update
sudo apt-get upgrade
sudo apt-get remove piwiz

sudo raspi-config
 - password
 - Boot to console autologon, no splash screen
 - localization time zone
 - Interfacing  - SSH SPI I2C Serial
 
wget https://raw.githubusercontent.com/adafruit/Raspberry-Pi-Installer-Scripts/master/adafruit-pitft.sh
chmod +x adafruit-pitft.sh
sudo ./adafruit-pitft.sh

Choose 1 tft 2.8 resistive
Choose 1 90 degrees
Console on tft Yes

reboot and console on tft visible

sudo sed -i "s+/dev/fb0+/dev/fb1+" /usr/share/X11/xorg.conf.d/99-fbturbo.conf
y       cat /usr/share/X11/xorg.conf.d/99-fbturbo.conf


sudo nano /usr/share/X11/xorg.conf.d/40-libinput.conf
At section touchscreen, add the following line
CODE: SELECT ALL
     Option "TransformationMatrix" "0 -1 1 1 0 0 0 0 1"

This matrix fits for the 90° turned display (see rotate=90 at /boot/config.txt). In case you have turned the display 270, the line must be
CODE: SELECT ALL
     Option "TransformationMatrix" "0 1 0 -1 0 1 0 0 1"

This design uses the hardware SPI pins (SCK, MOSI, MISO, CE0, CE1) as well as GPIO #25 and #24. All other GPIO are unused. Since we had a tiny bit of space, there's 4 spots for optional slim tactile switches wired to four GPIOs, that you can use if you want to make a basic user interface. For example, you can use one as a power on/off button.

We bring out GPIO #23, #22, #21, and #18 to the four switch locations!

The last known for-sure tested-and-working version is March 13, 2018 (https://downloads.raspberrypi.org/raspbian/images/raspbian-2018-03-14/) from https://downloads.raspberrypi.org/raspbian/images/

It works OK with recent Buster (Jan 2020), tested March 2020

Setting up the Touchscreen

Now that the screen is working nicely, we'll take care of the touchscreen. There's just a bit of calibration to do, but it isn't hard at all.

Before we start, we'll make a udev rule for the touchscreen. That's because the eventX name of the device will change a lot and its annoying to figure out what its called depending on whether you have a keyboard or other mouse installed.

Check if this already done

   sudo nano /etc/udev/rules.d/95-stmpe.rules

   to create a new udev file and copy & paste the following line in:
   SUBSYSTEM=="input", ATTRS{name}=="stmpe-ts", ENV{DEVNAME}=="*event*", SYMLINK+="input/touchscreen" 

   sudo rmmod stmpe_ts
   sudo modprobe stmpe_ts

Then type 
ls -l /dev/input/touchscreen

It should point to eventX where X is some number, that number will be different on different setups since other keyboards/mice/USB devices will take up an event slot

There are some tools we can use to calibrate & debug the touchscreen. Install the "event test" and "touchscreen library" packages with

sudo apt-get install evtest tslib libts-bin

Now you can use some tools such as

sudo evtest /dev/input/touchscreen

which will let you see touchscreen events in real time, press on the touchscreen to see the reports.

AutoMagic Calibration Script
If you rotate the display you need to recalibrate the touchscreen to work with the new screen orientation. You can manually run the calibration processes in the next section, or you can re-run the installer script and select a new rotation:

Try using this default calibration script to easily calibrate your touchscreen display. Note that the calibration values might not be exactly right for your display, but they should be close enough for most needs. If you need the most accurate touchscreen calibration, follow the steps in the next section to manually calibrate the touchscreen.
Manual Calibration
If the "automagic" calibration technique isn't working for you, or you have some other setup where you need to carefully calibrate you can do it 'manually'

You will want to calibrate the screen once but shouldn't have to do it more than that. We'll begin by calibrating on the command line by running

sudo TSLIB_FBDEVICE=/dev/fb1 TSLIB_TSDEVICE=/dev/input/touchscreen ts_calibrate

follow the directions on the screen, touching each point. Using a stylus is suggested so you get a precise touch. Don't use something metal, plastic only!

Next you can run

sudo TSLIB_FBDEVICE=/dev/fb1 TSLIB_TSDEVICE=/dev/input/touchscreen ts_test

which will let you draw-test the touch screen. Go back and re-calibrate if you feel the screen isn't precise enough!

X Calibration
You can also calibrate the X input system but you have to use a different program called xtcal (xinput_calibrator no longer works)

You can do this if the calibration on the screen isn't to your liking or any time you change the rotate=XX module settings for the screen. Since the screen and touch driver are completely separated, the touchscreen doesn't auto-rotate

Download and compile it with the following:

 Download: fileCopy Code
sudo apt-get install libxaw7-dev libxxf86vm-dev libxaw7-dev libxft-dev
git clone https://github.com/KurtJacobson/xtcal
cd xtcal
make
You must be running PIXEL (the GUI) while calibrating.

Before you start the calibrator you will need to 'reset' the old calibration data so run

DISPLAY=:0.0 xinput set-prop "stmpe-ts" 'Coordinate Transformation Matrix' 1 0 0 0 1 0 0 0 1
Now you'll have to run the calibrator while also running X. You can do this by opening up the terminal program and running the the xtcal command (which is challenging to do on such a small screen) OR you can do what we do which is create an SSH/Terminal shell and then run the calibrator from the same shell, which requires the following command:

DISPLAY=:0.0 xtcal/xtcal -geometry 640x480
Note that the geometry may vary!

If you are using a 2.4"/2.8"/3.2" 320x240 display with landscape orientation, use 640x480. If you're in portrait, use 480x640.

If you are using a 3.5" display with landscape, use 720x480, portrait is 480x720

Follow the directions on screen

raspberry_pi_xinput.png
Once complete you'll get something like:
adafruit_products_testxtcal.png
Run sudo nano /usr/share/X11/xorg.conf.d/20-calibration.conf and copy the 9 numbers into the TransformationMatrix option so it looks like:

 Download: fileCopy Code
Section "InputClass"
        Identifier "STMPE Touchscreen Calibration"
        MatchProduct "stmpe"
        MatchDevicePath "/dev/input/event*"
        Driver "libinput"
        Option "TransformationMatrix" "-0.000087 1.094214 -0.028826 -1.091711 -0.004364 1.057821 0 0 1"
EndSection
or whatever you got, into there.

You will want to reboot your Pi to verify you're do

Kedei 2 touch screen

Something I bought in 2015, 2 Kedei 2 lcd 3.5 inch touch screens. Worked, albeit slow.
With a Wheezy image, not to be updated due to the kernel doing its SPI thing to copy the framebuffer to the LCD screen via fbcopy.

March 2020, installed the Kedei screen on a Raspberry Pi V2 and inserted the archived SD card. It works!

Update? No, the official repository moved on. But there is a legacy repository!

Replace this line in /etc/apt/sources.list

deb http://legacy.raspbian.org/raspbian/ wheezy main contrib non-free rpi

and teh apt-get update works (be it with some warnings).

To test I installed MC and that went allright (be it with some warnings).

Screen quality is not too bad, screen refreshes are slow. In console mode it reminds me of the 9600 baud serial terminals!

Now I want autologon, no option in old raspiconfig!

From https://www.elinux.org/RPi_Debian_Auto_Login

sudo nano /etc/inittab
Scroll down to:

1:2345:respawn:/sbin/getty 115200 tty1
and change to

#1:2345:respawn:/sbin/getty 115200 tty1
Under that line add:

1:2345:respawn:/bin/login -f pi tty1 /dev/tty1 2>&1

Auto StartX (Run LXDE)
In Terminal:

sudo nano /etc/rc.local
Scroll to the bottom and add the following above exit 0:

su -l pi -c startx