I have a problem in the UART communication between NRF52832 and SIM868 module.
The problem is the data sent by NRF doesn't be interpreted by SIM868.
To see that i did tow tests:
When I send "ATD+phoneNumber" from NRF i got it in the TTL module but the SIM868 doesn't execute the command.
Now i send the same Command form TTL Module directly to SIM868 "ATD+PhoneNumber" and it was executed, and received the response in the NRF and TTL module
I think the problem can be Logic level difference between NRF and SIM868.
could anyone help in this problem?