Hi
Last week or so I have been going grey trying to figure out why my Uno has started to freeze, I was wondering if here is somebody who could help to get to the roots of this mystery.
Chronological sequence of events:
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I had the simple (ver1) version of my setup working perfectly for past 5 months. I call the simple solution: RFID reader, Uno and a relay module everything connected to the same 12V power supply.
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Then I had a failure – one cable had been damaged between the Uno and RFID reader. I changed the cable to resume the operation, but now the troubles started.
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Everything works when magnet lock is not wired up to relay - relay switches each time I put the RFID card to RFID reader. But when I wire up the magnet to the relay it works 1 to 10 times, and then I need to reset the Uno and it will work again 1 to 10 times, then needs again reset.
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During troubleshooting I have swapped out all components: Uno, relay, RFID reader, cable, magnet solenoid lock, tested also with standard 50kg magnet lock. Still it only works couple times when magnet is connected to relay.
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Then I decided to have separate power supply for each user (see ver2): independent 12V power for magnet, independent 5V supply for relay and independent 12V supply for Uno. Even after this I get the same behavior – it works well when nothing is connected to relay; but freezes after couple times when magnet is connected to relay.
Any ideas what could I try next?