Can DTM on nRF52840 be controlled by SPI interface?

[JPierpont]

We currently have a SPI interface between MSP and the Nordic nRF52840. In the DTM documentation it indicates UART is used to command the tests. Is it possible to do this using SPI?j

[endnode]

Theoretically yes, it's just not defined and not implemented in any example. But surely if you have some upper tester which will know how to run DTM commands over SPI instead UART then you can modify DTM FW examples from nRF5 SDK to communicate over SPI.

[Sigurd]

Why not use the UART ? The purpose of DTM is to test the operation of the radio at the physical level. Please read the DTM example project documentation here, and after that please take a look at our application note about DTM here.

[JPierpont]

Hi Sigurd, we are using SPI interface in our production firmware. Can we add an additional UART interface to be configured in the nRF52840 dedicated for DTM using GPIO pins? - Thanks, J

[Sigurd]

Hi,

Yes, The nRF5x have flexible GPIO mapping, so all pins can be individually mapped to interface blocks for layout flexibility. You can therefore use any free GPIO pin you have on your board for UART(E).

The nRF52840 have 2 UART(E) Peripherals. The first one can be configured to be used either with or without EasyDMA(either as UARTE0 or UART0), while the second one can only be configured with EasyDMA (UARTE1). The 2 UART(E) Peripherals each have its separate instance. See the Instantiation table here.

[JPierpont]

Thanks for the explanation Sigurd. Since we have SPI already in place it would seem advantageous to command DTM over this, however I do not see any testers that support SPI. Are you aware of any or is UART the de-facto standard for DTM?