Grove - Relay does not work

[jeffrey.yung]

Hi, the relay can be controlled through python and I can hear the sound on state transition from on to off or reverse, as well as the LED on and off respectively. However, when I connect a 220V computer fan, I hear the sound from off to on only and the fan cannot be switched on, nor the LED on the board is turned to red. Any idea?

[kavi]

Hi,

Can you please send us a picture of your experimental setup.

Thanks and Regards

[jeffrey.yung]

Hi Kavi, I moved it to D2 and it seems to work now, will run a few more tests to make sure. BTW, is there any way to query the status, whether the relay is on or off?

[kavi]

hi Jeffery,

There is an on board status indicator LED in the Grove Relay which will light up when the terminal gets closed.The Grove Relay is a normally open type.

Thanks and Regards

[jeffrey.yung]

Hi Kavi,

I conducted a few tests that still having the problem. I can only switch on once using D2, after I switched it off, then tried to switch it on again, it refused and the red LED in the GrovePi+ turned on. I recycled the power on the Pi3, the red LED in GrovePi+ turned off, but the relay does not work anymore. Then I connect the relay to D6, I could turn it on and off two times, then the GrovePi+ LED turned on. However, after I recycled the power on the Pi3, the relay could be turned on at least once. I have not turned it off again yet.

It seems that D2, D3 are not working now and I am not sure what will happen if I turned it off now. Please advise. Thanks.


Regards,
jY

[jeffrey.yung]

hi Jeffery,

There is an on board status indicator LED in the Grove Relay which will light up when the terminal gets closed.The Grove Relay is a normally open type.

Thanks and Regards

I am referring to detection through function call, not visual inspection. Thanks.

[kavi]

Hi Jeffery,

I would like to know which library you are using with the Grove relay and a photograph of the experimental setup to isolate the issue further.

Could you please check if you're using the library that is available in the following link.

Thanks and Regards

[jeffrey.yung]

Hi Kavi,

Nothing is really special: connecting the live wire to one terminal on the relay, another terminal is connected to a 220V fan; the neutral wire is connected to the other wire of the fan.It works as long as the relay switches properly. (If you look at the photo, the black wire going out from the left terminal is connected directly to the fan, it's just a matter of the view angle)

I did a few more tests and after the relay is switched on and off a several times more, the red LED on the grovepi+ turned on. Then I recycled the power of the pi, the relay could be switched on at least once.

Please advise. Also, is there any way to detect the status of grovepi+ red LED and reset it by API call?

BTW, apparently it is possible to use grovepi.digitalRead(relay) to get the status of the relay, if it's on (1) or off (0).

[jeffrey.yung]

Hi Kavi,

Any idea? Thanks.

[kavi]

Hi Jeffery,

If you have an Arduino can you please test with that and let us know if you face the same issue.

Thanks and Regards