Raspberry-Pi Rev 3
On the Raspberry-Pi 3 the auxilliary (or mini) UART port has been used to control the Wi-Fi and Bluetooth devices. As a result all add-on cards which use the UART no longer work. For example xbee and other transmitters, RS485 and unfortunately also the gertbot. There are several threads about this:
SolutionI found that the following worked for me:
- Add "dtoverlay=pi3-miniuart-bt" to the /boot/config.txt file (Does not work with very old OS versions)
- Also add "enable_uart=1" to that /boot/config.txt file
- Remove "console=serial0,115200 console=tty1" from the /boot/cmdline.txt file
As this swaps the mini UART back to pins 14 & 15 on the GPIO connector, the WiFi and Bluetooth functionality is lost.
Thus it is not possible to use gertbot and Wifi And Bluetooth at the same time.
I have heard that some people managed to use the software (bit-bang) UART emulator on pins 14 & 15 alongside WiFi and Bluetooth. Thus far I have not been able to get this working with the Gertbot. Probably because (Just as with e.g. xbee) the data is a packet oriented stream with no buffering and binary data.