Question here? Is there a board view or pdf with the component designators and their locations for the Yun Rev 2? I would like to remove U16A - MAX3375E and separate the ttyATH0 interface from the Arduino serial interface. This will allow me to directly wire the uart from an external PCB to the Atheros chipset and isolate the ATMEGA32U4. I don't need bridge functionality.
For the software side of my YUN setup, I have removed the YUN bridge interface. I am having issues with jitter on UART output pins 1 and 2 on the YUN header. The sketch was left blank other than disabling the onboard pull-ups. My goal was to get UART data from the header pins to the Atheros chipset to be delivered to /dev/ttyATH0 for use with pySerial.
What I have right now TX and RX work, but about every 200-220 chars sent it is sending a jittery pulse train. My device receiving the UART is an STM32F0 MCU. The issue has been validated because the UART onboard the Yun R2 fails, but when using a FT232 USB adapter on /dev/ttyUSB0 the STM board receives data continuously without locking up, which is the symptom that the YUN presents to my external board. The pulse train on the FT232 is also much more consistent. The STM board does not hang on an error RX when using the FT232 cable or RPI-2 as an interface so I would like to think the slave is functioning correctly but When Using the YUN it does hang.
Thanks,
If you need ay details lets me know.