Do you have the latest schematic and code you are using somewhere? I would like to try it and perhaps I can add something to the project. I have been for the last week trying to find out if something like this existed since 3dr batteries will die and dissapear from the market.Hi,
The resistors will limit the current draw to under 1mA per cell. This device will be left in the Solo and the battery will only be connected when you want to fly so won't drain the battery when not in use.
I am happy for someone to design an op amp circuit to add to the mix. When I looked into this it required more resistors, your example uses 14 compared to 8 for the voltage and would still require calibration. Also there is the op amp ICs to add to the circuit increasing the circuit complexity.
The chips I looked at could be used and I now have some to test. With the OLED using a software I2C these chips can be added to that. I paid NZ$7 for 3 of them so not too expensive.
I hope to get back into some circuit design work over the next few weeks and see how that goes.
Also do you happen to know what controller 3dr used in their circuit? could give us some ideas.
About using resistors perhaps just using a mosfet to but them off from the pack when not used could reduce the drain to 0, without adding a ton of components.
May I suggest to put all code and schematics in github so people can collaborate on it?
I think what you have done is awesome.