MakerGear Forum

Either of those should work. I recommended pin 4 to you previously.

Pin 13 is attached to an LED, but nothing else should be driving that LED. Still, you probably don't want to use it to get maximum power to your relay.

Thanks i am sorry i missed that i will use pin 4.

Did you get your circuit working?

I have been building all sorts of things with Arduinos for several years.

Out of curiosity, If you are using a relay to control power to the M2, but controlling the relay with a 5v signal from a free pin ... are you using a relay where driving the pin LOW opens the gap? If so, how are you planning to close the relay to get the M2 up and initiated in the first place - as the pin will be LOW when the system is off. Conversely, if you plan on opening your relay by driving the pin HIGH, then won't the gap close again as soon as the RAMBo loses power and all pins drop?

I solved a similar problem a few years ago using on of these [ http://www.pololu.com/product/750 ] with a solid-state relay, but the device was all battery powered. There are logic circuits you can put together of course... I'm just interested in your solution...

Sean

Update to project. I have completed all the circuits and have tested all but one. I am printing the box the electrincis are going in so I cant test the last circuit until that is done.

As soon at it is done I will post a video of it working and get you guys info.

Ok so the box is done and working. However I am not able to control digital pin 4 or 5. I only seem to be able to control digital pin 13 with the light. That once works for what I need however I dont know if that light ever turns on during a print. If it does it will turn off the printer. Any ideas? Any other pin I can turn on and off with 5v or does the m2 even use that light?

Other than the pin issue it is working. Later after the lighting stops I will try to take pics video if we can post videos.

Are you sure you're probing the correct pins? The pin numbering system is very confusing. There is the physical pins, the Atmel pin labels, and the Arduino pin labels. If you look at the schematic, you will see the Arduino pin numbers as the outermost numbers. If you find Arduino pin 4, it says next to it PG5. That is the NET to which it is connected. If you scour the rest of the schematic for PG5, you find it next to pin 6 of PWM EXT. That is the one you should be testing.

I am its on the same row as 13 and I can get that one just fine. can you control your pin 4 or 5?

Ah, I see the problem. In pins.h, pin 4 is assigned to PS_ON_PIN. It looks like you can send an M81 and it will drive that pin high. Try that.

I will try that. Pin 4 is not used by anything else right? Even with is in the code already?