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Topic: Arduino uno with ethernet module and relay (Read 238 times) previous topic - next topic

vj01

Hi

i am having a giant issue right now and was hoping someone can help me figure this out. iam not 100% this is a hardware issue however software wise it seems to be ok. i have an arduino uno connected to an ENC28J60 ethernet module. it has a 12v 2A input with regulators dropping the voltage down to 5V for the arduino and 3.3v for the ENC28J60, which works perfectly. on my pcb there is also a 5V relay

5V relay

this relay is connected to the arduino, which then switches the relay on and off. the relay takes in the same input voltage the 12 2A and when switched on it powers a small computer NC-885 CPU board. i send a udp packet with the value reboot which truns the relay off and then on to restart the pc.
the issue i am having is that the whole ethernet and adruino works perfectly when sending the reboot command, when the pc is not connected during the time i power up my pcb. but when i connect the pc to the output of the relay then power up my pcb, everytime i send the command reboot it doesnt work.

i have a feeling it is due to the load when the pc is connected when powering up my pcb, but cant not be sure.

thank you

ieee488

this relay is connected to the arduino, which then switches the relay on and off.
Not a good idea.

TonyWilk

this relay is connected to the arduino
How exactly is this relay 'connected to the arduino' ?

Quote
when i connect the pc to the output of the relay then power up my pcb, everytime i send the command reboot it doesnt work.
Nothing at all ? No 'tick' from the relay?  no LED's briefly blinking ?

Quote
i have a feeling it is due to the load when the pc is connected when powering up my pcb, but cant not be sure.
That seems highly likely.

Yours,
 TonyWilk

vj01

How exactly is this relay 'connected to the arduino' ?

Nothing at all ? No 'tick' from the relay?  no LED's briefly blinking ?
That seems highly likely.

Yours,
 TonyWilk

Hi the relay is connected using a transistor whihc is connected to the arduino to turn the relay on and off

Mikeb1970

Hello,

I've been reading this topic several times, and I wonder if this couldn't be an IP issue, since you say your only having problems when your PC is running? Have you checked if the PC obtains it's own IP address and there isn't a conflict there?

With regards,

Mike

vj01

Hello,

I've been reading this topic several times, and I wonder if this couldn't be an IP issue, since you say your only having problems when your PC is running? Have you checked if the PC obtains it's own IP address and there isn't a conflict there?

With regards,

Mike
there isnt an ip issue due to the fact that they are both connected to a switch with port forwarding

vj01

i have taken out the relay and bypassed it straight to the output, as i thought it could be a power issue however it all works. so i have narrowed it down to something wrong with the relay.

i do have two questions if someone could help me with this.

if i have reversed the relay accidentally, would it still work or will it have blown?

since the relays switching current is 2A would a relay with a higher amp or lower amp work?


TonyWilk

i have taken out the relay and bypassed it straight to the output, as i thought it could be a power issue however it all works
That makes no sense at all to me.

So please answer:

1) You said earlier: "the whole ethernet and adruino works perfectly", so does the relay operate at all ?
   (even when the NC-885 is not connected)

2) Does it only stop working when you connect the NC-885 to the relay ?


Yours,
 TonyWilk

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