I have an Uno controlling 3 servos. There is also a 4 channel remote control receiver. A 12V wall wart powers the Uno via Vin and the receiver module (which has 4 relays on it). A separate battery pack is used to power the servos to reduce the current draw from the Uno. Grounds of all three modules and the servos are connected.
There are also 3 limit switches that connect 3 GPIO pins on the Uno to ground. The pins are configured with INPUT_PULLUP.
And the receiver's relays switch 4 GPIO pins on the Uno to ground. The pins are configured with INPUT_PULLUP. This is the only connection to the Uno from the receiver.
Another user posted a similar problem with burning out Arduinos. See Burnt out 3 UNOs: Help! However, I don't see me having the same issue as sillyface, because my high current devices should be powered by their own power supply (servos via 6V battery pack).
A good description, however, a schematic will tell us everything we need to know.
The main point is, it is not safe to connecting high current loads to your Arduino's 5 volt pin.
Elaborate on this:
"And the receiver's relays switch 4 GPIO pins on the Uno to ground. The pins are configured with INPUT_PULLUP. This is the only connection to the Uno from the receiver."
There is a 4 channel remote control receiver controlled by a fob. When a button is pressed on the fob, the corresponding relay on the receiver is closed.
This module is powered by the same 12V source as the Uno.
The relay contacts switch ground to a GPIO pin on the Arduino. The pins are configured as INPUT_PULLUP.
BTW, I don’t see any high current draw on the Uno...let me know if you do. And nothing is connected to the 5V pin!
Can you post links to the specific devices you are using please? And label the pins on the Uno?
I'm a little unhappy you are powering the uno from a 12V "wall wart", especially when you have a 6V rail available. Have you measured the 12V output? it MAY not be fully regulated, or have a LOT of ripple.
@djsfantasi Installation and Troubleshooting is for Problems with the Arduino itself NOT your project. It says so in the description of the section. Therefore I have moved your post here. Please be more careful where you post in future.
Which implies that you are switching 12V into an Arduino pin. That would blow it up, but I doubt that your circuit is correctly reflecting what you actually have.
The receivers outputs go to A0-A3
The servos are connected to 10-12
The limit switches are connected to 5-7
I used the 12V source because it is needed for the remote receiver. Actually, the 6V was added to isolate the servo power. Hadn’t considered using it to power the Arduino as it’s too close to the minimum power needed for the regulator and there’s a danger it will drop too low when the servos operate.
The batteries are not rechargeable. They will simply be replaced. This is for a magic trick and will be used infrequently for a few minutes at a time.
The voltage output has been measured with a DVM. it’s not possible to get a measurement of ripple. The project is in the UK; I’m in the US. And the guy building it is doing so at my direction and is NOT electronics savvy.
