You are reading a single comment by @allObjects and its replies.
Click here to read the full conversation.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
@allObjects
All grounds should go to a single point... and because you measure with Espruino, I'd put all grounds to one point where also Espruino GND connects to (as short as possible)... Both power supplies - the Espruino (for controls) and the peripherals (sensors) - go to one point, to which also all sensor grounds and Espruino ground goe (Espruino with as short as possible line). I'd not connect the sensor grounds on the Espruino pin. Intentionally I said both power supplies... I would separate them... or having good filtering / decoupling.
From your context I conclude that your power environment is 12 or 24 volts with +4-3V and +6-6V... (Car or Truck/heavy Vehicle DC ...or solar/UPS battery bank). You have options to run different resistors to limit current even more while having full range over 3.3V by the gauge's/sensors max resistance. Going beyond 5 V supply for the sensors, you would have to protect the inputs with some Zener diodes.
Depending on the noise and length of sensor line lengths, you could go for higher resistors than 270 ohms... of course all dependent on the accuracy you expect from measures... and shielded wires could help with it.