I measured the resistance between the gnd and 5V pins on the Arduino Uno to be 800 Ohms, without anything attached. I actually had 2 arduino unos and they both had the same value, so I don’t think that was just a mistake on one board.
I made a shield (pdf of the layout attached), and the resistance between gnd and 5V pins (on the shield) can’t be read using a max of 2MOhms (so it’s larger than that).
When I connect the shield to the arduino, the resistance between 5V and gnd is very low that its as if they’re shorted (the multimeter beeps). This halts the uploading process; I’m guessing because the program doesn’t receive the data its expecting from the arduino.
When I tried the circuit on a breadboard, it actually works and I can upload programs. I think the resistance between pins on the breadboard is much higher (open circuit) than that on the shield that I made (a finite resistance, albeit higher than 2MOhms), so it’s acting like 2 resistors in parallel, with the resulting resistance lower than the 800 Ohms.
I am not doing this as a hobby or playing around; I have a project with very tight deadlines, and I need to solve this asap (1 week max). Unfortunately, I don’t have time to change the pcb to have wider wires or more space between wires, if that would solve the issue.
BUT I do think that the main issue is with the Arduino - 800 Ohms between pwr and gnd? Seriously?
projectbak.pdf (35.3 KB)