When 3 devices are connected to each other through the same UART lines, the third device can interfere with the communication between the other two.
Ideally, only one set of UART pins is connected to another. That means you can either:
- Use a gen4-IB which breaks out the 5 commonly used pins (5V, TX, RX, GND, RST)
- Use a gen4 Breakout board which breaks out all 30 pins from the 30-way FFC
- Connect the FFC directly to your application board