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AlessandroAU / Chorus32-ESP32LapTimer

This is an ESP32 port of the popular Chorus RF Laptimer
GNU General Public License v3.0
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INA219 incorrect reading #124

Open marcfon opened 4 years ago

marcfon commented 4 years ago

The reading from my INA219 off by about 0.3v compared to when I read voltage with a multimeter across the battery + and -.

I've got the VIN- connected to + terminal of the battery according to this schema.

Did a miss a wire or setting somewhere?

Smeat commented 4 years ago

Sorry, I don't have an INA219, so my ability to help is limited. But it seems the wiring diagram is missing something, as VIN- is unconnected. You better use Jye's PCB as a reference. Also make sure you are measuring as close to the INA219 as possible.

marcfon commented 4 years ago

Thanks for thinking along Smeat. You don't have to have VIN- connect if you're just monitoring voltage. If you also want to measure current then you do so it depends. I fiddled around a bit more but couldn't find the cause. Not a dealbreaker but curious if more people ran into this.

AlessandroAU commented 4 years ago

What's the hardware look like? a drop of 300mv is easily explained by thin wires and a current draw of couple amps.