About Davey

So i have a somewhat automated locker, driven by a CtrlX. The CtrlX sends TCP messages to another PCB to open/close the locks and detect their status.  Then I also have a CtrlX usb -> arduino mega -> PN532 rfid reader. The arduino reads the rfid badges of our employees, who can use their badge to log in, and borrow or return items. With the ctrlX we can see a list of users who borrowed and returned each item with time + date.  I just discovered one issue:  We have 2 identical installations. But on one installation the CtrlX won't start when the arduino is plugged in. I can plug the arduino in after startup, and everything will work. But if the arduino is plugged in from the start, then the status led stays off. The power led indicator stays blue. Even if you unplug the arduino in this state, the CtrlX won't start. At this point I can not log in either. When i remove the arduino from the usb, I can start up. When i go to the logs I don't see anything to tell me what is preventing the startup. I have another (spare) arduino uno i plugged in, which also prevents the ctrlX from starting.  The arduino that allows the ctrlX to start, lets both CtrlX start. The two arduino that don't allow the ctrlX to start, do so on both CtrlX. Both arduino that prevent startup, also prevent startup without anything connected. Just usb supply. I wonder if the power supply is very limited? Or can you think of any other reason this could happen? Both mega boards are rev3. All 3 arduinos have a ATmega16U2 USB chip. ... View more