oe7drt-website/content/notes/raspberry-pi/index.md

---
title: Raspberry Pi
date: 2024-01-27T11:01:31+0000
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---

Some basic info about Raspberry Pi of any version.

## Activity LED codes

### Up to Raspberry Pi 3 models

#### Actual models

| LED Activity | Description                                                                                      |
| :---------------- | :----------------------------------------------------------------------------------------------- |
| 3 flashes         | start.elf not found                                                                              |
| 4 flashes         | start.elf not launch-able (corrupt)                                                              |
| 7 flashes         | kernel.img not found                                                                             |
| 8 flashes         | SDRAM not recognized. You need a newer bootcode.bin/start.elf firmware, or your SDRAM is damaged |

#### Older models up to Raspberry Pi 3

| LED Activity | Description                          |
| :---------------- | :----------------------------------- |
| 3 flashes         | loader.bin not found                 |
| 4 flashes         | loader.bin not launch-able (corrupt) |
| 5 flashes         | start.elf not found                  |
| 6 flashes         | start.elf not launch-able            |
| 7 flashes         | kernel.img not found                 |

### Raspberry Pi 4

| Long flashes | Short flashes | Description                         |
| :----------- | :------------ | :---------------------------------- |
| 0            | 3             | Generic failure to boot             |
| 0            | 4             | start\*.elf not found               |
| 0            | 7             | Kernel image not found              |
| 0            | 8             | SDRAM failure                       |
| 0            | 9             | Insufficient SDRAM                  |
| 0            | 10            | In HALT state                       |
| 2            | 1             | Partition not FAT                   |
| 2            | 2             | Failed to read from partition       |
| 2            | 3             | Extended partition not FAT          |
| 2            | 4             | File signature/hash mismatch - Pi 4 |
| 4            | 4             | Unsupported board type              |
| 4            | 5             | Fatal firmware error                |
| 4            | 6             | Power failure type A                |
| 4            | 7             | Power failure type B                |

## Freeze a package with apt/apt-get

<https://askubuntu.com/a/18656>

## Raspberry Pi 4

4GB version, if that information is of any use.

#### WiFi setup

Run `wifi-menu`. It does not survice a reboot though!

I prefer `iwctl` or NetworkManager, so what I do:

```console
# pacman -S networkmanager
```

### No network after boot

Sometimes I make mistakes in my initial `wpa_supplicant.conf` file (that I'd place on
the boot partition of the new Raspberry Pi SDcard). Recently my `wpa_supplicant.conf`
file was totally messed up (a bracket too much I think).

So there is a quick way to connect to a WiFi network with the use of `nmcli` (NetworkManager).

```console
$ sudo nmcli device wifi connect [ssid] password [password]
```

You can view networks with (no need for _sudo_):

```console
$ nmcli device wifi list
```

### Moving to testing (from bookworm)

Why would you want to do that in the first place? Well, most
packages on debian _stable_ are quite old -- hence the name _stable_.

If you need newer packages, you should consider moving to the _testing_
branch. I moved my Raspberry Pi 4 to _testing_ because of the starship
prompt that I use on my computers -- it needed a newer version of the
`rustc` package.

First of all, upgrade to the latest packages.

```console
$ sudo apt update && sudo apt upgrade
```

Now change the release name (e.g. `bookworm`) to `testing` in `/etc/apt/sources.list`:

```
deb http://deb.debian.org/debian testing main contrib non-free non-free-firmware
deb http://deb.debian.org/debian-security/ testing-security main contrib non-free non-free-firmware
deb http://deb.debian.org/debian testing-updates main contrib non-free non-free-firmware
```

Then update step by step.

```console
$ sudo apt update
$ sudo apt upgrade
```

> Restart services during package upgrades without asking?

Answer with <kbd>Yes</kbd>.

Finish the update:

```console
$ sudo apt full-upgrade
$ sudo reboot
```

### Python 3

#### Installing non-packaged modules

I could not find `aprslib` as a package, so I had to install this myself.
Debian did not allow the installation as it did before, so I had to create
a virtual environment. And it went like this:

```console
$ python -m venv ~/.env
$ source ~/.env/bin/activate
$ pip install aprslib
$ deactivate
```

I now have a similar line in my crontab:

```crontab
3 * * * * /home/dominic/.env/bin/python /home/dominic/bin/aprs_sendstatus.py
```

We could also create virtual environments per application, module, package etc.

<https://www.raspberrypi.com/documentation/computers/os.html#python-on-raspberry-pi>

## Raspberry Pi 3

### UPS Plus

An **uninterruptible power supply** (UPS) is very useful if you have your own servers at
home. I've been using one with my old DiskStation (NAS[^1]) but I got rid of the DiskStation
at the end of 2023. I got the UPS Plus for the Raspberry Pi now for a while but never tested
all its features yet (well, I haven't used it much to be honest).

Though, I have some quick notes to remember:

Some software is needed to get status information about the batteries (which are of type 18650).

```console
$ python3 -m venv .
$ curl -LsO https://raw.githubusercontent.com/geeekpi/upsplus/main/install.sh
$ bash install.sh
```

Any errors can be resolved by installing by hand. In my notes I thought that info is enough, so
here we are :wink:

We may have to edit our crontab:

```cron
* * * * * /home/dr/bin/python3 /home/dr/bin/upsPlus.py > /tmp/upsPlus.log
* * * * * /home/dr/bin/python3 /home/dr/bin/upsPlus_iot.py > /tmp/upsPlus_iot.log
```

Getting information:

```console
$ python3 bin/upsPlus.py
------------------------------------------------------------
------Current information of the detected Raspberry Pi------
------------------------------------------------------------
Raspberry Pi Supply Voltage: 5.028 V
Raspberry Pi Current Current Consumption: 571.068 mA
Raspberry Pi Current Power Consumption: 2570.227 mW
------------------------------------------------------------
-------------------Batteries information-------------------
------------------------------------------------------------
Voltage of Batteries: 4.208 V
Battery Current (Charging) Rate: 30.000 mA
Current Battery Power Supplement: 263.415 mW
Successfully set the protection voltage to: 3700 mV
------------------------------------------------------------
Currently charging via Type C Port.
```

The Raspberry Pi will continue to work if you remove the power cable.

[^1]: [Network Attached Storage](https://en.wikipedia.org/wiki/Network-attached_storage)

## Raspberry Pi 2

### WiFi adapter

The Raspberry Pi 2 does not have any WiFi capabilities so an adapter
is needed to make use of your local WiFi network. I found [this small
adapter](https://www.amazon.de/gp/product/B003MTTJOY/) and can confirm
it as a working unit.

![picture of the small Edimax EW-7811UN wireless adapter](edimax_wifi.jpg "It is not available
on Amazon any more, but they suggest another device as its successor. I can only speak for the
one that I own: **Edimax EW-7811Un**")

## Raspberry Pi Pico W

### Using MicroPython

<https://micropython.org/download/RPI_PICO_W/>

I did the dumb thing and made the `boot.py` file break which led to an endless
loop showing me only the Error code and restarting...

I was able to stop the script by quickly pressing <kbd>CTRL+D</kbd>,
<kbd>CTRL+C</kbd> on the serial console but never was able to update the broken
file without it doing a soft-reboot which loads `boot.py` again instantly...

After some research I was glad I found [pico-nuke](https://github.com/polhenarejos/pico-nuke/releases).

Boot into uf2 loading (pressing BOOTSEL while power on) and place the correct .uf
file (`pico_nuke_pico_w-1.1.uf2`) on the mounted device.

On OpenBSD there is no response but you can see the filesystem unmounted/removed.
Unplug the USB and plug it in again booting into uf2 loading, copying over the
MicroPython uf2 file again.