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sagar
Associate II
May 7, 2019
Question

What should be the output value of ADC if input is not connected to dedicated pin? I am getting some values (230).

  • May 7, 2019
  • 2 replies
  • 1287 views

Hello, As I am working on analog inputs I require ADC. STM32F334 Nucleo board has 12-bit ADC (2) with 21 channels, I am using ADC1 Channel 1.

After programming without applying any input to the pin (PA0) I am getting some values through USART2.

Can anybody help me out.

Thanks in advance.

This topic has been closed for replies.

2 replies

Ozone
Principal
May 7, 2019

Check the schematic, is anything connected to this pin ?

If not, pull it to GND with a resistor (say, 1k to 10k), value should be about zero.

Apply other voltages up to Vref, and check values for consistency.

Never let an ADC input floating.

Always check Discovery/Nucleo board schematics when deciding about pin usage.

sagar
sagarAuthor
Associate II
May 7, 2019

Yes. Its working.

Thank you..