I am using a Nano 33 BLE for a BLE project and need all 8 analog inputs for various bits and pieces.
However, I would also like to report battery voltage to the client.
I am just wondering if there is another internal analog that gives battery voltage, so I can still use the 8 externals for other things.
Cannot see any reference to one, but thought I'd ask.
Hello
did you check the data sheet of the Nano 33 BLE ?
Yes, didn't see anything. Just hoping there might be something internal not normally mentioned.
If its not in the datasheet, it is unlikely to exist, manufacturer's don't try to hide selling points like this. Perhaps an analog switch chip could be used to expand the number of signals one of the ADC pins can access?
Google secret voltmeter for the UNO and see if it’s possible to do something similar for the Every
I have experience to use an internal analog comparator with one RC circuit to measure the battery voltage in a project using ATmega16U2 (It is don't have ADCs).
At the time to measurement, GPIO operates the voltage of capacitor from GND to 5 V via resistor, and measures the time it takes to charge to the battery voltage connected to the comparator another input pole.
Since the internal pull-up resistor is used for R of the RC circuit, the only external component is the capacitor.
The linearity is a bit bad, but I was able to obtain a resolution of about 20 mV.
The data acquisition is slow, but it's no problem because I only monitored the battery once every few seconds in that project.
It's like a trick... but I hope it will be a hint.
That's a very neat idea. I'll think on that.
Thank you for having interest.
I found this old document by Atmel.
[Application Note : Low Cost A/D Converter]
It is like I was does that.
This is written about using analog comparator to ADC by AVR.
But since you are likely to have knowledge, I think that you can do it for other uC it enough just by knowing the "mechanism" from this documents.
By the way, the document shows another pin and an external resistor to charge the capacitor.
But as posted above, I used the AC pin as an output and also used the internal pull-up resistor for charging capacitor.
I used 1nf film capacitor for good stability, but honestly MLCC may be fine.
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