Read but not write over uart, nrf51822, pro micro.

[HFrg]

Hi,

I seem to be able to read over UART but not write. I have my nrf51822 (https://www.waveshare.com/wiki/Core51822) setup to a pro micro (3.3v, 8mhz). I am confident the wiring is correct since I am able to read data over UART (both on 250k baud) then output over I2C (my main form of debugging since I am using an st-link v2).

The code on the pro micro sends a number and the nrf51822 sends debug data and the number over I2C to the pro micro which then forwards this to the arduino serial monitor.

Code on nrf51822: https://pastebin.com/2Ed4h7ER

Code running on pro micro: https://pastebin.com/vupvZt3p 

Output to the serial monitor: https://pastebin.com/5cAEc0cK 

Also, how would I use the nrf_drv_uart? All of the examples for uart are with the app_uart module and I would like to be able to send arrays over UART.

Details:

On archlinux, using make files with gcc, stlink-v2 (openocd) for flashing, compiling the pca10028 board (would this cause any compatability issues?).

Thank you

Thank ou

[HFrg]

I have found the mistake. I had flow control enabled which uses the Clear to send pin but I was only using uart via two wires. Should have read into the configuration a bit more closely.

[Susheel Nuguru]

Thanks for coming back to post the conclusion.