2024-04-23, 08:14 PM
(2024-04-23, 08:02 PM)SARASTRO Wrote: I have already discovered the problem. I thought that by powering the ADS1115 at 5v, I could measure a signal up to about 5v. (The limit is VIN+0.3V) and I calculated the voltage divider accordingly.
It looks like the chip actually has a 5 to 3.3v internal step-down, so it can't actually measure signals higher than about 3.6v.
In these conditions, it was somewhat above the range (26,400) and for this reason I was getting a "null" as voltage instead of the actual measurement.
Fixed by modifying the voltage divider R values.
Thanks for the help.
The internal gain amplifier is adjustable to 2/3 & can read voltages above 3.3v though not sure if that's `possible in the openplotter setup