Is the 5V power of the ARDUINO DOCK different from the real Arduino UNO?

[Paolo Moro]

| Note: Remember that the ATmega runs on 5V, and therefore it reads 5V as logical high.

I use a classic NFC reader PNR532 V3 (like: https://images.app.goo.gl/uouKyD4WnnLDmuhHA) - SPI connection.

I used a lots of that reader connected directly on 5V of the omega PINOUT (expansion header) with ARDUINO DOCK 2 with onion board.

Now I bought 100 new NFC reader and if I connect them on an ARDUINO UNO everything work very good, but if I use the Onion Power on the ARDUINO DOCK 2 (5V) they don't work fine.

I noticed two thing:

1. with the 3,3V of the expansion header the new readers works good
2. these new reader are more powerfull, the reading range is wider.

Is the 5V power of the ARDUINO DOCK different from the real Arduino UNO?

many many thanks!!!

Paolo

[György Farkas]

@Paolo-Moro 0n Arduino Dock 2 the 5V of the Expansion Header is same as the Input 5V (provided by the micro USB or the Barrel Jack) - ie. each 5V on the Dock is common.