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October 13, 2024, 09:42:33 21:42


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Author Topic: M5stack voltmeter  (Read 1346 times)
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Wizpic
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« on: April 27, 2024, 08:41:16 08:41 »

Just a quick question it says that the m5stack voltmeter can measure up to +/-36v

I was just wondering would it be possible to modify it so that it can measure +/-99v absolute voltage ?
Here is the unit I’m talking about

https://thepihut.com/products/voltmeter-unit-ads1115?variant=40639062212803&currency=GBP&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&gad_source=1&gclid=CjwKCAjwxLKxBhA7EiwAXO0R0AMRAb8CxLa1cHosetK2a7DsY-WmK3wBwx6ZPV-xsVZqoaTx7aTAXhoC0uYQAvD_BwE
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sphinx
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« Reply #1 on: April 27, 2024, 09:32:46 09:32 »

if you dont have the schematics it might get trickier to find the the voltage divider where youu could change the range of the input voltage but i would think it is possible to modify,
unless its potted with some gunk inside or components are wiped of identification numbers

if it is high impedance input you could allwayes make an external voltage divider
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« Reply #2 on: April 27, 2024, 10:07:47 10:07 »

This is the schematic  for it.
If I'm correct and if I do the calculations with the 11k and 680k resistor values on the input I would get +/- 573Mv  so for 99V then the 680K would need to be 2M ?
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« Reply #3 on: April 27, 2024, 10:25:50 10:25 »

using a voltage calculator i get 1889.524kohms

Posted on: 2024-04-27, 10:40:59 - Automerged

you can allways lower the 11kohms to get some othe value depending on the values one can get

and how exact you want it to be

the more bits you use the more noice you will have as well 2^16 will give you 1.5mV resolution and that can get noisy this needs to be calculated for as well
« Last Edit: April 27, 2024, 10:40:06 10:40 by sphinx » Logged

laws of physics are not laws at all, just assumptions and formulas that work as long as we don't figure something new that wrecks the calculations. the infinite onion try to peel that one
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