serial_lte_modem sample: Sending AT commands to modem using putty or TeraTerm does not work.

[pascal_dao]

Hello guys,

I am attempting to send AT commands to an nrf9160 over UART. I started by loading the serial_lte_modem sample and sending commands using the LTE link monitor which works fine. But whenever I try to send the same commands using some other serial terminal  it does not work. I do not get anything back from the nrf9160. I played with the CR LF settings on these serial terminals, and tried manually appending \r\n to the commands, but it still only responds to commands from the link monitor.

Regards.

[Georgi Valkov]

The serial_lte_modem sample is heavily broken. Unlike the AT client sample which simply works with PuTTY out of the box, for the serial_lte_modem you need to configure PuTTY, Terminal, Keyboard to CR LF. Then it will accept commands until you send an empty line. Once you do that, it will not replay to any further commands until you power cycle the board. On top of that I cannot send PING or connect to anything, even though my Thingy:91 is registered to an NB-IoT network, and has a valid and enabled IP address context.

While I hear comments that I should not expect different samples to operate likewise, the fact is that they are so inconsistent that you need to have different setting in every single one and each has its own quirks and problems. And if you choose to automate the AT commands over BLE, things get even worse.