How to enter directe test mode？

[Linxi]

We use Nrf_studio to connect our board by uart to enter direct test mode. But an error occurs in serial connection.

I want to know， use our own project program is allowed ？ Or must program official dtm project can enter direct test mode ？

[FormerMember]

To use DTM, you will have to program DTM firmware to the chip, it can be useful to have a look at the DTM example documentation. To test DTM, you can use the python script that comes with nAN34.

[Thomas Y]

Hi we didn't expose UART physical pin on the NRF52 we only have JTAG to program the module. Would RFCOM driver allow to send AT command to NRF52 once DTM firmware is flashed to the chip ? if so do you have a recommended BLE USB module we can use to validate or an RFCOM app on Android or IOS. Looking at the sample physical pin are used so In this case can various APP be used to flash the NRF and put it automatically in  DTM test mode without sending AT command. In this case how to set it in specific frequency receive only mode. Can you point to  API to do so 

[FormerMember]

The DTM interface is by the Bluetooth Spec, vol 6, part F, defined to either use use UART or HCI, so one of those has to be used. 

I'm not familiar with RFCOM, but I don't think it will work. 

For UART communication, only two pins are needed. Is there no way you can expose two pins for UART for the DTM testing? 

[kphalak]

So how does testing process work? Do we need to replace our application firmware with DTM example firmware? Or DTM and application should co-exist?