adc channel connectivity

[Piyoosh]

I am using ADC channel with DMA to get linear hall sensor data ,its giving bur after some time adc pin not working.

but same code working with another board, what can be problem.

[SofLit]

Hello,

First, this statement is not clear :"its giving bur after some time adc pin not working."

Second please provide more details: what do you mean by is not working? wrong conversion value? giving always 0? what is the MCU part number? is it an ST board or custom board?

[ONadr.1]

If the board stopped measuring on the ADC and does not measure even after power ON-OFF, while another does, the IO pin of the MCU has probably been destroyed. The cause may be an ESD discharge or exceeding the maximum allowed voltage on the pin.

[Piyoosh]

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@SofLit wrote:

Hello,

First, this statement is not clear :"its giving bur after some time adc pin not working."

Second please provide more details: what do you mean by is not working? wrong conversion value? giving always 0? what is the MCU part number? is it an ST board or custom board?

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I am using STM32F103C8T6 chip on my pcb,Initially  ADC value was increasing and decreasing between their resolution value (0-4095) according to input but after multiple uses it`s giving 0 or 4095 on same configuration.The input is a linear hall sensor which is directly connected to ADC1 and also i am using DMA function with pin. One more thing that when i am using these pins like simple GPIO_output its working properly.

[Piyoosh]

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@ONadr.1 wrote:

If the board stopped measuring on the ADC and does not measure even after power ON-OFF, while another does, the IO pin of the MCU has probably been destroyed. The cause may be an ESD discharge or exceeding the maximum allowed voltage on the pin.

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okay, is there any chance to destroyed only adc functionally due to high signal variation? if yes which part of adc will destroy?

[SofLit]

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but after multiple uses it`s giving 0 or 4095 on same configuration. The input is a linear hall sensor which is directly connected to ADC1 and also i am using DMA function with pin.

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Did you measure the voltage on the sensor output? Are you sure it's an issue on the MCU side and not on the sensor side?

[ONadr.1]

For example analog multiplexer, ADC input buffer.

Have you tried the pin functionality as a digital input? Have you tried the ADC on a different pin? Have you tried the ADC to measure the internal reference voltage? These tests might specify what the problem is, but if it is found, the MCU will be partially inoperable anyway.

[Piyoosh]

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@SofLit wrote:

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but after multiple uses it`s giving 0 or 4095 on same configuration. The input is a linear hall sensor which is directly connected to ADC1 and also i am using DMA function with pin.

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Did you measure the voltage on the sensor output? Are you sure it's an issue on the MCU side and not on the sensor side?

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yes i measure the voltage by multimeter, the sensor is working properly in fact it`s working well with another MCU.

[Piyoosh]

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@ONadr.1 wrote:

For example analog multiplexer, ADC input buffer.

Have you tried the pin functionality as a digital input? Have you tried the ADC on a different pin? Have you tried the ADC to measure the internal reference voltage? These tests might specify what the problem is, but if it is found, the MCU will be partially inoperable anyway.

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yes I tried the pin as digital input also as digital output and it`s working and other pins are also not working as analog input(ADC) and the rest functionality is working.

[SofLit]

Hello,

I think you marked my solution by mistake I unmark it then.

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the sensor is working properly in fact it`s working well with another MCU.

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What do you mean by another MCU? is it a second board with the same schematics? or a completely different board?

What about VDDA/VSSA pin connections?

Are you sure about the voltage level at VDDA?