not receiving data in serial when connecting the tx and rx pin with lpc controller

[hariharan_srm]

Hi i am using ble app uart example of nordic 5 sdk sodt device 140 for nrf52840 dk . i am configured that as peripheral my code works fine suddenly i face a issue that data is not receiving on serial com of ble app uart peripheral code . i faced this issue when conncting the tx-0.6 and rx-0.8 pin to my lpc controller i have not made any changes in ble app uart code. i had debug the issue data is receiving on the ble and data is also sent through uart ble rx ready event of ble nus data hanlder. when i remove the tx pin which is connected to the rx pin of lpc controller data is receivied is the serial com(virtual com) independlty everything is working but when cnnecting the tx pin to the lpc i am not receiving the data in serial what may be the issue. while debug also no error or anything occured . removing the tx pin everythings works data is received and connecting the tx pin data is not received. i checked with two board same issue is happening suddenly. in that ble rx event data it is receiving in chunks

[Kenneth]

Hello,

If there are issues with serial communication here are some suggested debug steps:

1. In addition to RXD and TXD, make sure ground is connected between the two boards.

2. Make sure the supply voltage is about same level.

3. Make sure baudrate is the same.

4. If hadware flow control (cts and rxd) pins are used, make sure these are also connected.

If you still can't find the problem, then make sure to connect a logic analyzer to the pins, so you can check that all the above are correct (and also check data).

Kenneth