Forum >DFrobot relay shield V2.1 AREF Shorted to Ground?
DFrobot relay shield V2.1 AREF Shorted to Ground?
DavidValeri 2015-03-11 22:33:27 6245 Views4 Replies I attempted to use the AREF pin on the relay shield with an Arduino Uno. Without the shield, the Uno reads reference voltage via AREF and the ADC pins work as expected. With the Shield in place, voltage out of my reference source dropped to near zero as the AREF pin appears to be shorted to the GND pins on the shield, effectively grounding the AREF pin on the Uno.
The short was verified with a multimeter. The relay portion of the board appears to be working fine.
Am I missing something here or do I have a bad shield?
The short was verified with a multimeter. The relay portion of the board appears to be working fine.
Am I missing something here or do I have a bad shield?
2015-03-24 06:04:07 I solved the problem by cutting the AREF pin off the shield and wiring my AREF voltage directly to the Arduino header.
This would have been a great opportunity to show off this company's customer service. You could have either helped me to understand why I am wrong about the pin being shorted to ground or you could have agreed that there is something wrong with the board and offered to replace it.
Instead you chose radio silence.
For anyone reading this down the road, I contacted technical support about the issue via email on the same day I posted this topic. DavidValeri
This would have been a great opportunity to show off this company's customer service. You could have either helped me to understand why I am wrong about the pin being shorted to ground or you could have agreed that there is something wrong with the board and offered to replace it.
Instead you chose radio silence.
For anyone reading this down the road, I contacted technical support about the issue via email on the same day I posted this topic.
DavidValeri 2015-03-17 06:57:55 I can try your code to double check, but I am pretty sure the short is in the relay board as the resistance values I quoted before were taken with the relay shield disconnected from the Arduino testing only the pins on the relay shield.
I'll double check but I believe my code called "analogReference(EXTERNAL);" in setup before any analog reads with the 3.3v source tied to AREF through the relay shield pins. DavidValeri
I'll double check but I believe my code called "analogReference(EXTERNAL);" in setup before any analog reads with the 3.3v source tied to AREF through the relay shield pins.
DavidValeri 2015-03-13 09:16:14 Powered with a 9V battery for testing while I wait for my power supply to arrive. Power was fed in via the vin pin on the shield. The shield was attached to the Arduino Uno R3 via the standard Arduino headers for stacking shields.
I don't understand what the power source has to do with the fact that there is less than 1Ohm resistance between the AREF pin on the shield and any of the ground pins on the shield? It would seem that grounding the 3.3V regulator via the AREF pin would result in a voltage drop no matter what power source I used. DavidValeri
I don't understand what the power source has to do with the fact that there is less than 1Ohm resistance between the AREF pin on the shield and any of the ground pins on the shield? It would seem that grounding the 3.3V regulator via the AREF pin would result in a voltage drop no matter what power source I used.
DavidValeri 2015-03-12 21:21:25 Hi David,
This relay shield need an external power supply. Could you connect a power resource to the power port and try agian? Anyway, how do you connect the module? Grey.CC
This relay shield need an external power supply. Could you connect a power resource to the power port and try agian? Anyway, how do you connect the module?
Grey.CC 