dtoverlay instructions

INSTALL.md

@@ -17,6 +17,12 @@ $ cargo run --release -p dc-motor-driver-hat
 
 ## Raspberry Pi
 
-On the Raspberry Pi, ensure that `boot/config.txt` contains the line `dtparam=i2c_arm=on,i2c_arm_baudrate=400000`. It is important not to let the default 100kHz speed which causes some bit flipping because of a hardware bug in the BCM2712 SOC with regard to clock stretching.
+On the Raspberry Pi, ensure that `boot/config.txt` contains the following line which defines a software I²C bus:
+
+```txt
+dtoverlay=i2c-gpio,i2c_gpio_sda=2,i2c_gpio_scl=3,bus=8
+```
+
+Ensure that the line `dtparam=i2c_arm=on` is not present: that would activate the hardware I²C bus, which cannot be used due to a hardware bug in the BCM2712 SOC with regard to clock stretching.
 
 The Python module is located in `controller/python/controller.py`.