Receiving Garbage Over BLE UART When Using "SAADC UART Timer Driven Scan Mode"

[Liam]

I am working with the BL652 Module from Laird, and with Keil 5, using a ST Link SWD programmer clone.

I am using the ble_app_uart_timer_driven_scan_mode from the ADC examples on github: https://github.com/NordicPlayground/nRF52-ADC-examples

I can connect to the device using the nRF Uart v2.0 app, receive senseless data:

I am not sure what could be causing this. I did set the program to be scanning analog 0, 1, 2, 3, rather than what it was downloaded as. 

Could the baud rate be off? I believe the reference is correct, which is VDD (3.3 V). When I use a voltmeter, I am reading 0 volts on AIN1, 2, and 3, and ~ 1 V on AIN0.

Thank you for the help!

[Martin Lesund]

Hi Liam,

First off, I would like you to use the "uart" app inside the nRF Toolbox app. This is the updated version of "nRF Uart v2.0".

 From the first look it seems like the baudrate can be off.

Are you running the unmodified "ble_app_uart_timer_driven_scan_mode"  example?

Have you tested the standard "ble_app_uart" example as well?

[Liam]

Martin, thank you for the reply, and sorry for the delay.

I get the same result when I use the nRF Toolbox app. 

The "ble_app_uart_timer_driven_scan_mode"  example is unmodified EXCEPT for that I changed the four pins read in default to four different analog pins. (0-3)

I can connect to the device normally when the "ble_app_uart" example is loaded, but I am not sure how monitor the com port -- no port is created by the ST Link programmer, that I can tell.

[Martin Lesund]

Hi Liam,

I have been informed that you will test this on the nRF52DK.

Please let me know your results.

Please check this thread for the solution of your issue.

 "The ADC values are not converted to a string before sent over NUS. If you want to display the values as a string, you have to convert it to a string before sending it. You can use sprintf() function or similar for this."

 

Best Regards,

Martin L.

[Liam]

This did it. Thank you!