Entering DTM mode to test continuous TX @ fixed frequency for factory testing

[MaheshHM]

Hi

We are trying to get the DTM mode working for the NRF52 2nd BLE for testing BLE TX power and RSSI at the factory.

(1)HW setup is shown

(2) Procedure

We have referred to the link below and the example.py scripts. Below are the steps we have followed before we ran the python scripts

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fstruct_appnotes%2Fstruct%2Fappnotes_nan34.html

(3)BT module was flashed with the DTM firmware “2020_05_08_BLSD_DTM_CT40_V2.hex” along with serial# and MAC addresses.

Please let us know if we are missing any other step/config to put the device into DTM mode as we are reusing the hex files from another project.

What would be the SDK version that must be used for DTM tests in case we don't have the SDK which was originally used to generate the hex files?

(4)We have run the example.py  script on the PC with the DUT com port field updated to COM41.
We did not observe any UART transactions from PC when scripts were run. HW connections for the COM41 port were verified physically by looping TX to RX and it works fine.

(a)Can you please share the example code ( python script ) used in the factory to test constant_carrier-continuous TX power measurement?

(b)What is the value to be updated in ‘'GoldenSerialPortName'’ in the example.py code snippet shared below

Best Regards

Mahesh HM

[MaheshHM]

Hi

I tried 'direct_test_mode_pca10056.hex' in the path suggested by you from the nRF5_SDK_15.0.0.

I think the UART pins are not correctly configured in this Hex file as I see no activity on the UART TX line (PC->nRF)

P1.04 Pin-H1 is the UART TX (out direction)

P1.07 Pin-G1 is the UART RX (in direction)

From the main.c

I can see that we need to configure the UART TX and RX. can you please share an example / hex file with about pins configured as TX and RX?

static void uart_init(void)
{
uint32_t err_code;
const app_uart_comm_params_t comm_params =
{
RX_PIN_NUMBER,
TX_PIN_NUMBER,
RTS_PIN_NUMBER,
CTS_PIN_NUMBER,
APP_UART_FLOW_CONTROL_DISABLED,
false,
DTM_BITRATE
};

[Håkon Alseth]

Hi,

 

 

MaheshHM said:

P1.04 Pin-H1 is the UART TX (out direction)

P1.07 Pin-G1 is the UART RX (in direction)

The init routine reflects what should be written to the PSEL register:

https://infocenter.nordicsemi.com/topic/ps_nrf52840/uarte.html?cp=4_0_0_5_33_8_25#register.PSEL.RXD

 

For P1.04, you should write 32+4 = 36.

For P1.07, you should write 32+7 = 39.

 

Then recompile and flash your board, and try to connect again in the direct test mode PC application.

 

Kind regards,

Håkon 

[MaheshHM]

Hi

Can you please let me know if there is any sequence that must be followed to enter the DTM mode after the hex file is flashed eg. Toggle a GPIO, Enter the device to reset before sending DTM commands from the GUI?

Please let me know if there is any command sequence to be sent on UART

Regards 

Mahesh HM

[Håkon Alseth]

Hi,

 

There is no sequence that needs to be inputted. Once the dtm project, with the correct uart pins, is manually flashed, you should be able to start a test via the PC application. If it still fails, then the nRF is not responding over the UART interface, meaning that there's a connection problem.

 

Kind regards,

Håkon

[MaheshHM]

Hi

Thanks for your inputs. I was able to enter the DTM mode and test the TX power measurements for our design

Is there a way we can directly send the commands to transmit 0 dBm in constant Tx frequency 2440MHz (ch 17) using command line UART raw sequences? Factory team may not use GUI for the automation..

Any suggestions will be very helpful