CC2541 Keyfob ADC Sampling Issue

Robert P

Other Parts Discussed in Thread: CC2541, CC2540

I'm using the CC2541 Keyfob reference design to try and sample the ADC on the open pins on the test connector (i.e. P0_6 and P0_7). I've tried using the three sample projects for the ADC in the peripheral projects zip, but those values do not change with respect to change in input. Moreover, I modified the keyfob code to attempt to sample the ADC using the battery monitor service with the channel switched to AIN6, but it also does not change with respect to input. Any ideas what I could be doing wrong?

HAL_ADC is defined as TRUE and it does actually attempt to sample it. The device is has the same problem when powered by the debugger as well as the battery.

over 11 years ago

0 Eirik V over 11 years ago

TI__Guru 56590 points

Hello Robert,

Have you tried to run the ADC software example without the BLE stack?

Does it work then?

0 Fredrik K over 11 years ago

TI__Guru** 106705 points

Hi Robert,

I am not sure if you have seen the user guide: http://www.ti.com/lit/pdf/swru191 . If not, check out the ADC chapter, it should give you some more insight into the inner workings of it.

Cheers,
Fredrik

0 Robert P over 11 years ago in reply to Eirik V

Prodigy 20 points

Eirik V said:

Have you tried to run the ADC software example without the BLE stack?

Does it work then?

I did try running without the BLE stack using all three example projects in the ADC subfolder of the peripheral examples. I also tried using hal_adc.h without the stack as mentioned in other posts.

Fredrik K said:

I am not sure if you have seen the user guide: http://www.ti.com/lit/pdf/swru191 . If not, check out the ADC chapter, it should give you some more insight into the inner workings of it.

Yes I have gone through it several times.

I just wanted to add that I tried the same code on the CC2540 USB dongle using ADC input P0.2 instead of P0.6 on the CC2541 Keyfob and it works fine. Any reason other than damaged ADC that would cause this sort of problem?

Thanks for your help.

0 Eirik V over 11 years ago in reply to Robert P

TI__Guru 56590 points

Make sure that no other peripheral is using the same GPIO. Could you post only the relevant code you change?

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CC2541 Keyfob ADC Sampling Issue