Hi,
May I know what is the hardware layout for measuring external voltage using SAADC? I may not be understanding the infocenter or the datasheet for setting the external reference pin
Thank you!
Hi,
May I know what is the hardware layout for measuring external voltage using SAADC? I may not be understanding the infocenter or the datasheet for setting the external reference pin
Thank you!
Also, another puzzling issue is when connected to a 9v battery with common ground,
The measure voltage from ADC shows a drop of nearly 3v!
<info> app: 6.59
Measured voltage: 9.54 from multimeter
I am using the NRF52840 preview DK
Measuring 5v or VDD works fine however
************ Solved **************
Make sure the gain settings is within the voltage range
Also, another puzzling issue is when connected to a 9v battery with common ground,
The measure voltage from ADC shows a drop of nearly 3v!
<info> app: 6.59
Measured voltage: 9.54 from multimeter
I am using the NRF52840 preview DK
Measuring 5v or VDD works fine however
************ Solved **************
Make sure the gain settings is within the voltage range
Hi Luke
Luke.L said:
************ Solved **************
Make sure the gain settings is within the voltage range
Do you mean that you solved both issues by this, or does the fluctuation problem still persist?
Best regards,
Simon
Hi Simonr
The fluctuation problem still occurs. Even when tying the voltage divider tying to ground, I get the following results(in V):
<info> app: 0.15
<info> app: 0.12
<info> app: 0.09
<info> app: 0.15
<info> app: 0.12
<info> app: 0.12
<info> app: 0.14
<info> app: 0.11
<info> app: 0.09
<info> app: 0.12
I am not sure if this is related to the precision of the ADC, but in my application I am required to detect voltage levels from 25-4v, this leads to me using a fairly high step down in my voltage divider, R1: 1M ohm, R2: 100k ohms. Would this setup cause problems? Should I revert to software filtering instead?