I'd like to use the Teensy 4.0 to monitor cell voltages of multiple Battery Packs. The basic idea is to use voltage dividers to scale down the voltages below 3.3V and read the voltage using the Teensys' ADCs. Since this is just one of many Tasks, and I plan to measure a multitude of cells, I use an analog switch (ADG728) to reduce the amount of Analog Pins I need. The schematic shows the basic idea. In the example schematic Pin 7 would be around 50V
I was going to use the analogRead() function with an analogReadResoultion(12).
However I have some questions regarding this design and would appreciate some tips. Thanks in advance!
1.) I worry that the chosen resistor values are too high. Do I need to adjust those and if not, how do I chose the capacitors to get an accurate reading. Each cell voltage is read at a very low frequency.
2.) Can I connect the output of the analog multiplexer directly to an analog Pin on the Teensy or should I add a 3.3V zener diode to gnd as a further precaution.
3.) I can not guarantee, that the Teensy is powered when the battery cells are connected. Am I correct that this is a problem and what is the best way to fix this?
I was going to use the analogRead() function with an analogReadResoultion(12).
However I have some questions regarding this design and would appreciate some tips. Thanks in advance!
1.) I worry that the chosen resistor values are too high. Do I need to adjust those and if not, how do I chose the capacitors to get an accurate reading. Each cell voltage is read at a very low frequency.
2.) Can I connect the output of the analog multiplexer directly to an analog Pin on the Teensy or should I add a 3.3V zener diode to gnd as a further precaution.
3.) I can not guarantee, that the Teensy is powered when the battery cells are connected. Am I correct that this is a problem and what is the best way to fix this?