merge

.gitignore

@@ -225,3 +225,4 @@ cython_debug/
 # PyPI configuration file
 .pypirc
 
+*.html

README.md

@@ -13,6 +13,7 @@ Scripts and documentation for setting up a Raspberry Pi (Zero W 1 or 2) for use
 - [Starting on Raspberry Pi Zero](https://reykjavik.instructure.com/courses/6589/pages/starting-on-raspberry-pi-zero-w)
 
 ## References and Links
+- [Sparkfun GPIO pinout](https://cdn.sparkfun.com/assets/learn_tutorials/6/7/6/PiZero_1.pdf)
 - [Guide to creating ssh keys](https://pimylifeup.com/raspberry-pi-ssh-keys/)  Of note, this guide is a little dated as it suggests using RSA keys and many people are moving toward EDCSA keys.
 - [Raspberry Pi Connect](https://connect.raspberrypi.com)
     - [Setting up Raspberry Pi Connect](https://www.raspberrypi.com/documentation/services/connect.html)	
@@ -21,6 +22,7 @@ Scripts and documentation for setting up a Raspberry Pi (Zero W 1 or 2) for use
 - [Turning your Raspberry Pi Zero into a USB Gadget](https://learn.adafruit.com/turning-your-raspberry-pi-zero-into-a-usb-gadget/serial-gadget)  Official Adafruit guide to gadget mode to allow the USB port to be used as a serial console to connect to it.   We had trouble getting it to work in 2026 due to some changes in Raspberry Pi OS.
 - [Python gpiozero library](https://gpiozero.readthedocs.io/en/stable/) a simple interface for working with GPIO devices
 - [CircuitPython Libraries on Linux and Raspberry Pi](https://learn.adafruit.com/circuitpython-on-raspberrypi-linux/installing-circuitpython-on-raspberry-pi) This is one option for GPIO, I2C, SPI, and PWM access in python.
+- [Comparing Rasbperry Pi python interfaces](https://raspberry.tips/en/raspberrypi-tutorials/raspberry-pi-gpio-python)
 
 ## For the Future
 - [Setting up Zeroconf to use local names (.local) to access your Pi](https://learn.adafruit.com/bonjour-zeroconf-networking-for-windows-and-linux): this does not work on iot-research because multicast and MDNS are broken.

Scripts/gadget.sh

@@ -2,10 +2,32 @@
 # Adapted from
 # "Using OTG mode on Raspberry Pi SBCs"
 # https://pip-assets.raspberrypi.com/categories/685-app-notes-guides-whitepapers/documents/RP-009276-WP/Using-OTG-mode-on-Raspberry-Pi-SBCs
+
+# This script only works if you are running it as root
+if [ $(id -u) -ne 0 ]; then
+    echo "Please run as root or use sudo"
+    exit 1
+fi
+
+
+# Is the dwc2 overlay installed?  Nothing will work if it isn't.
+if lsmod | grep -q "dwc2"; then
+    systemd-cat -t gadget.sh -p info echo "DWC2 module loaded, setting up OTG gadget serial and ethernet"
+else
+    systemd-cat -t gadget.sh -p warning echo "DWC2 module missing.  Aborting OTG setup."
+    systemctl disable serial-getty@ttyGS0.service
+    exit 1
+fi
+
 sudo modprobe libcomposite
 cd /sys/kernel/config/usb_gadget
+if [ -d "MyGadget" ]; then
+    systemd-cat -t gadget.sh -p warning echo "MyGadget already exists.  Aborting OTG setup."
+    exit 1
+fi
+
 # Create our new gadget
-sudo mkdir MyGadget
+mkdir MyGadget
 cd MyGadget
 # Add some boilerplate data that the gadget needs
 echo 0x1d6b > idVendor # Linux Foundation’s USB VID. Replace with your own VID if required
@@ -30,6 +52,7 @@ echo "Config 1" > configs/c.1/strings/0x409/configuration
 ###  Remember to create the storage block device first
 ##  cd /root
 ### Example: Make a 256 MB file to act as "USB stick"
+##  Only create it once or it will delete the previous content
 ##  sudo dd if=/dev/zero of=drive.bin bs=1M count=256
 ### Create a VFAT file system on the backing store
 ##  sudo mkfs.vfat drive.bin
@@ -45,9 +68,14 @@ mkdir functions/acm.usb0
 ln -s functions/acm.usb0 configs/c.1/
 
 ## Ethernet (RNDIS and ECM)
+## Of note, this may cause the IP to show up as 127.0.0.1
+## and wireless to suddenly fail to connect
 mkdir functions/ecm.usb0
 ln -s functions/ecm.usb0 configs/c.1/
 
 ## USB Device Controller update
 UDC=`ls /sys/class/udc`
 echo $UDC > UDC
+
+# Enable the gettys
+systemctl enable serial-getty@ttyGS0.service

connect.md

@@ -0,0 +1,10 @@
+# Initial connection to the Raspberry Pi
+Now that you have an image with ssh and Raspberry Pi connect on your SD, you can connect to the pi
+
+
+## Connecting using Raspberry Pi Connect
+1. Login to https://connect.raspberrypi.com if you haven't already
+1. Look at the list of devices, find the one you want, and click on "Connect"
+![connect-devices.png](Graphics/connect-devices.png)
+1. A remote shell window will pop up
+![connect-shell.png](Graphics/connect-shell.png)

gadget.md

@@ -1,49 +1,56 @@
 # Gadget Mode to setup a serial connection over USB
 Prepare Raspberry Pi OS connection over a microUSB serial cable
 
-Important:  You will want to disable the serial console on RX/TX if you are trying to use that serial port for communicating with other devices.
-
 Based upon Adafruit guide: https://learn.adafruit.com/turning-your-raspberry-pi-zero-into-a-usb-gadget/serial-gadget:
 The author discovered the guide was out of date, consulted the [2025 Raspberry Pi whitepaper on OTG](https://pip-assets.raspberrypi.com/categories/685-app-notes-guides-whitepapers/documents/RP-009276-WP/Using-OTG-mode-on-Raspberry-Pi-SBCs), found additional errors, and was finally able to correct them thanks to this blog https://www.isticktoit.net/?p=1383
 
+## Important :
+- **Using the Gadget Mode will make the usb port unable to connect to a mouse or keyboard!!!** You will need to disable it make them work again.
+- You will want to disable the serial console on RX/TX in `raspi-config` if you are trying to use that serial port for communicating with other devices.
+
+
+## Procedure
+
 Make sure you have your USB cable plugged into the left port **USB** and not the right port marked **PWR**.
 1. Open a connection to the device via ssh or Raspberry Pi Connect
 1. Become root (the superuser)
-    ```
+```
-	sudo su
+sudo su
-	```
+```
 1. Enable the DWC version 2 USB peripheral device tree overlay by appending it to the end after the `[all]` category (which is at the end)
-   ```
+```
-    echo "dtoverlay=dwc2" >> /boot/firmware/config.txt
+echo "dtoverlay=dwc2" >> /boot/firmware/config.txt
-	```
+```
 1. We add the required module `dwc2` for loading at startup
-    ```
+```
-	echo "dwc2" >> /etc/modules
+echo "dwc2" >> /etc/modules
-	```
+```
 1. Check that we can load the libcomposite module
-    ```
+```
-    modprobe libcomposite
+modprobe libcomposite
-	```
+```
 1. Put a copy of this repository in root's home directory using git
-      ```
+```
-	  apt install -y git
+apt install -y git
-	  git clone https://gitea.cs.ru.is/RU-V207/rover-pi.git		
+git clone https://gitea.cs.ru.is/RU-V207/rover-pi.git
-	  ```
+```
 1. Go to Scripts and test if the `gadget.sh` runs without errors and hopefully a Serial port appers in Device Manager or equivalent
-      ```
+ ```
-	  cd rover-pi/Scripts/
+cd rover-pi/Scripts/
-	  ./gadget.sh
+./gadget.sh
-	  ```
+```
-1. Install the systemd script
+1. Install the systemd
-      `cp serial-ether-gadget.service /lib/systemd/system/.`
+```
+cp serial-ether-gadget.service /lib/systemd/system/.
+```
 1. Enable the service
-    ```
+```
-	systemctl enable serial-ether-gadget.service
+systemctl enable serial-ether-gadget.service
-	```
+```
 1. Enable the getty (which connects a login terminal to the serial port)
-      ```
+```
-	  systemctl enable serial-getty@ttyGS0.service
+systemctl enable serial-getty@ttyGS0.service
-	  ```
+```
 1. Reboot and see if the serial port appears
 
 # Connecting to the serial terminal

imager.md

@@ -23,7 +23,7 @@ We don't have many monitors and keyboards in V207 for students to use, so we wil
 ![imager-ssh_nokey.png](Graphics/imager-ssh_nokey.png)
 1. Once you have uploaded your `id_edcsa.pub` file it should look like this. 
 ![imager-ssh_key.png](Graphics/imager-ssh_key.png)
-1. Since we don't have enough monitors, we will need another way to setup the initial connection.  The officially supported option is Raspberry Pi Connect.  You will need to:
+1. Since we don't have a monitor, keyboard, and mouse available, we will need another way to setup the initial connection.  The officially supported option is Raspberry Pi Connect.  You will need to enable it then:
     1. Register for an account first at https://connect.raspberrypi.com
 	2. Confirm your account with email
 	2. Login with that account
@@ -42,7 +42,7 @@ We don't have many monitors and keyboards in V207 for students to use, so we wil
 1. Now you get to watch the writing then verifying.
 ![imager-writeimage-progress.png](Graphics/imager-writeimage-progress.png)
 ![imager-writeimage-verifying.png](Graphics/imager-writeimage-verifying.png)
-1. The process is complete!
+1. The process is complete!  Now you can [connect to your pi](connect.md)
 ![imager-complete.png](Graphics/imager-complete.png)
 1. Take the SD card and put it into your pi.
 1. When you first boot it, it can take 10 minutes to finish configuring itself.  Usually when the LED stops blinking for at least 30 seconds, it is done.

lgpio/blink.py

@@ -0,0 +1,19 @@
+#!/usr/bin/python
+# From https://raspberry.tips/en/raspberrypi-tutorials/raspberry-pi-gpio-python
+import lgpio
+import time
+
+# Open GPIO chip (0 = /dev/gpiochip0, on Pi 5 gpiochip4 also possible)
+h = lgpio.gpiochip_open(0)
+
+try:
+    lgpio.gpio_claim_output(h, 18)   # GPIO18 (pin 12) as output (MOTA1)
+
+    for _ in range(5):
+        lgpio.gpio_write(h, 18, 1)   # HIGH
+        time.sleep(0.5)
+        lgpio.gpio_write(h, 18, 0)   # LOW
+        time.sleep(0.5)
+    
+finally:
+    lgpio.gpiochip_close(h)          # Always close!

lgpio/pwm-test.py

@@ -0,0 +1,25 @@
+#!/usr/bin/python
+# From https://raspberry.tips/en/raspberrypi-tutorials/raspberry-pi-gpio-python
+import lgpio
+import time
+
+# Open GPIO chip (0 = /dev/gpiochip0, on Pi 5 gpiochip4 also possible)
+h = lgpio.gpiochip_open(0)
+
+try:
+    lgpio.gpio_claim_output(h, 16)   # GPIO16 as output (MOTA2)
+    lgpio.gpio_write(h, 16, 0)   # LOW
+
+    # Hardware PWM on GPIO18 (pin 12) must be PWM-capable
+    # Frequency: 1000 Hz, duty cycle: 50%
+    lgpio.tx_pwm(h, 18, 1000, 50)
+    time.sleep(2)
+
+    # Reduce duty cycle to 20%
+    lgpio.tx_pwm(h, 18, 1000, 20)
+    time.sleep(2)
+
+    lgpio.tx_pwm(h, 18, 0, 0)   # Stop PWM
+    
+finally:
+    lgpio.gpiochip_close(h)          # Always close!