gpio trouble

Hello everyone! I recently received my beaglebone black in the mail. Prior to ordering it, I had done days of research and decided that it was time that I bought one. When I got it in the mail, I eagerly opened it and got started. I used it as a standalone pc, ssh-ed into it, and worked with it in cloud9. However I couldn’t seem to get pins 1-4 or 5 working smoothly. When I had an LED hooked up to one of them, it seemed to be blinking with one of the user LED’s (this changed sometimes. One time it was blinking with user3 and another time with user0 etc.). Mostly when I connect an LED to one of those pins it just lights dimly and ignores anything that I say to it on the command line (e.g. echo 1 > /sys/class/gpio/gpio38/value). There are a few other things that i noticed that weren’t quite right. I am wondering if I have a defective board or if I am doing something wrong. Any help would be great. Thanks!

The drive current on the GPIO pins is 6 mA.

What other things are not quite right?


Well for one, some of the other gpio pins such as pin 13 on P8 won’t operate properly. When I try to work with it over cloud9, it doesn’t respond to any changes. For instance in the a simple blink sketch, if the setInterval is (blink, 1000) and I change it to (blink, 100), it continues blinking at once per second.

What Gerald is saying is that in general you should not expect to drive an LED directly - you will want to drive a transistor which can then supply perhaps 20 ma or more to your LED and at the correct voltage. Perhaps you are already doing this, but you didn’t say.

I don’t know anything about the Cloud 9 interface, but if is blinking by just using the shell (" echo 1 > pin whatever…) with “sleep”, sleep may not recognize any increment of less than integral seconds. I’d look into that. Maybe see if it works for longer intervals like 3 or 5 seconds…

Speaking strictly for me, when something doesn’t work, 99.9% of the time it’s something I did wrong, not the hardware etc.

You might try the new Bonescript stuff in the latest image based on Debian.It my work better, but I can’t say for sure.


I will try that. I am using cloud9 when I use the sleep command. The funny thing is that some of the pins are outputting voltage right after the board has been powered on and they won’t respond to anything. I’ll try updating a few things. See if that works. Thanks!

I have the same problem with P8 pins and am using the cloud 9 interface ? did you find a solution?