Unable to read ADC on nRF52840 Preview DK using the SAADC example.

[EmbeDev]

I'm running the SAADC example from the nRF5_SDK_17.0.0_9d13099 SDK. I didn't add any modification to the code. except for replacing NRF_LOG with printf. 

The power supply of 1.0 V is applied to the p0.03 (A0) pin on the board (ground from the power supply is connected to the GND on the board).

I'm getting the following values which are the same as in the case when the power supply is not connected.

SAADC HAL simple example started.ADC event number: 0
19, 34, 38, 26, 14, 
ADC event number: 1
8, 14, 23, 40, 34, 
ADC event number: 2
18, 10, 9, 16, 32, 
ADC event number: 3
38, 27, 13, 8, 11, 
ADC event number: 4
20, 35, 38, 28, 13, 
ADC event number: 5
9, 12, 19, 36, 37, 

If anyone can tell me what can be wrong with this test setup I would appreciate it.

[Karl Ylvisaker]

Hello,

Which nRF52840 PDK version do you have?
Please refer to the nRF52840 Compatibility Matrix to see which SDK version is compatible with your chip revision.

If you tell me which PDK version you have, I can point out the correct SDK version for you to use.
Then, lets try the example again from the correct SDK version, I suspect that a change between the chip revisions is the cause of this, since SDK v17 is only compatible with nRF52840 revision 2.

Looking forward to resolving this issue together,

Best regards,
Karl

[EmbeDev]

Hi,

Thank you for your help.

I'm not sure which version of PDK I'm using. How and where can I check it? Also, the link for the compatibility matrix is not active.

Best regards.

[EmbeDev]

Hi Karl Ylvisaker

I've just tried with SDK 14.2.0 and SDK 15.3.0 and I'm getting the same result. What else I can try?

Regards.

[Karl Ylvisaker]

Hello,

Sorry for the late reply.
I have updated the broken compatibility matrix link.
You will first have to check which SoC version you are using by looking at the numbers printed on the chip.
Then, you can check which SDK and SoftDevice version the SoC is compatible with here.
Depending on which SoC version you have, we can identify which SDK and Softdevices you may use.

Looking forward to resolving this together!

Best regards,
Karl

[EmbeDev]

HI Karl,

I'm sending you the pictures of the DK and chip. Can you tell me from the picture which SDK should I use?

https://1drv.ms/u/s!AjnYJbMTfDefhxchv0EkqYjM46Ld?e=MCdoZ3

https://1drv.ms/u/s!AjnYJbMTfDefhxgYilWp6b-q13PZ?e=7XjDbF 

Best regards,

Milan.