since days i am trying to get a GSM / GPS module to work with an arduino pro mico but without any success. I almost blamed the GSM module until i tried different arduinos. The problem was, that the module doesnt even turn on. Now i (think) i found the Problem: The 5V output is extremely different on different rduino models - in fact so different, that sometimes its so little, that it does not get recognized as 5V line. Here is my findings:
Arduino UNO 5V Out: 4,8V Leonardo: 4,2V Teensy3.2: 4,9V Pro mini: 4,0V Due: 4,8V Mega: 4,1V
I originally wanted to use the pro mini - so i played around with it for days until i had the idea to measure the voltages... (yeah... i am a total beginner...).
So my question here: is this normal!?!? So i can only use the uno, Teensy and Due (wich is way too big) to reliably power 5V modules!? I dont get it...
Al the tests were made with the same (powered) USB Hub.
Am i wrong or is this normal - so do i need some kind of stepup/down thing in every cirquit?
Any Ideas would be awesome!
Thank you so much!