Hello everyone, and thanks in advance for reading this!
On a current project, I’m working with a network of Arduino UNOs R3, each with an AnalogShield installed (to be precise, it’s 4 Arduinos+AnalogShields total, communicating over I2C). I immediately found a problem when I connected all their Vin ports together to a 12V power supply: they sourced too much current (my main power supply was reading more than 1 A!). So I quickly stopped that and tried connecting the 5V ports together to a 5V power supply. At first this was OK, but soon they started to source too much current again. I also tried powering one of them via USB and connecting all the 5V ports together… This works most of the time, but some times the 5V line’s voltage oscillates badly or they start sourcing too much current again... It's funny because sometimes things seem to work, and then stop working.
I checked the health of all Arduinos and they are perfect. And I checked powering all Arduinos by themselves (no shields) both through their Vin and 5V ports, and that works with no issues... So it must be an issue with the AnalogShields...
For the moment, as a temporary measure, I’m powering all of them independently through their USB ports, and connecting only their grounds together. But in my final configuration I’d like to be able to power all of them with a single power supply.
Can anybody point to where the issue could be?