Wireless MCUのトピック回复： read adc value problem

read adc value problem

darkblue — Tue, 12 Sep 2023 06:41:20 GMT

I use adc0_dp0 to read value in KW36 sdk, and I got voltage like 1 or 0. Can I just init adc0_dp0 as single mode?

回复： read adc value problem

Gavin_Jia — Tue, 12 Sep 2023 07:39:00 GMT

Hi @darkblue ,

You are correct.

When the channel is selected as a Single-Ended Input, the positive input (ADC0_DP0) is the selected input signal.

Best regards,

Gavin

回复： read adc value problem

darkblue — Tue, 12 Sep 2023 07:49:18 GMT

thanks for replying. When I enabled diff mode and used adc0_dm0 to measure voltage, I found that the value was incorrect. The actual voltage is 1.09v, but it reads 64189. It seems like already over range. how can I fix that ?

回复： read adc value problem

Gavin_Jia — Thu, 14 Sep 2023 10:30:22 GMT

Hi @darkblue ,

Please check the result value in the code, which cannot be defined as the uint type, because there will be a result of less than 0 when using diff mode.

Gavin

回复： read adc value problem

darkblue — Thu, 14 Sep 2023 10:58:41 GMT

thanks. I understand the minus number in diff mode. But actually, I want to use the single end mode

I can't find how to make adc0_dm0 working in single mode in MKW36A512RM. That means adc0_dm0 can be only configured in diff mode in mkw36a512?

回复： read adc value problem

Gavin_Jia — Mon, 18 Sep 2023 06:27:36 GMT

Hi @darkblue ,

Sorry for my late reply.

I got your point now. If you configure ADC to the single-end mode, you only need to consider dp which should connect input signal. dm connected to GND internally, no additional configuration required, and it can be ignored.

Best regards,

Gavin

回复： read adc value problem

darkblue — Mon, 18 Sep 2023 09:40:16 GMT

Thanks for reply. Due to project design I can only use dm to measure voltage instead of dp. Which means I have to connect dm to input signal. meanwhile the dp may be 0 or 1 or float. Does that work? In this situation the dp can be ignored?

回复： read adc value problem

Gavin_Jia — Tue, 19 Sep 2023 06:41:11 GMT

Hi @darkblue ,

In this case, we can only choose single-ended mode. Please refer to the Reference Manual [Link] , chapter 4.8.2.3.1 ADC0 Channel Assignment listed all options.

Best regards,

Gavin