V2 Controller Board Magic Smoke

So I got my v2 controller put together, and think I may have smoked the Arduino Pro Mini. Red light comes on for a second and goes off (you can hear the steppers click when you plug up also)

Seen smoke come out near the voltage regulator on the arduino.

So from what I’m seeing, there’s 2 version of the pro mini, a 3.3v version and a 5v version. I was trying a 3.3 version. From what I’m reading, when powering with 12v using the raw pin, you need to use the 5v version because of beefier components.

So am I correct that I need to be using the 5V version?

Also, Im scratching my head, (I’m not a electronics person), I know the power system on this board converts the VIN power you supply to 12v to power the components, but what device is converting the 12v power down to 5v for the other devices to run?

Reason I ask, is i’m going to start taking some readings to see if I have any shorts anywhere and wanted to know how I need to trace this thing out.

So got the new arduino 5v version, and for giggles, I hooked it up to the raw pin. Saw smoke.

12v reads perfect. Anyone give me some tips on how to troubleshoot this board. Some of these SMD’s are tiny lol.

I’m wondering if something on the 5V rail is shorted. I’ve checked with a multimeter and everything I’m checking looks good (even though I cant really test the 5v going to it since the arduino is smoked, just checking resistance to ground)

Should I supply 5V to the board directly (without the arduino connected, etc) and see what heats up? lol

If I hook my arduino up to a external 5v now via vcc pin instead of raw (without being connected to the satnogs controller), both led’s light up solid and that’s it. Reset button doesnt work, can’t program it, etc.


Did you figure out what was causing the failure in the Arduino? I have the same issue, but not at startup. What happened is that initially when plugging the power supply with the V2 board the motors did not turn. I was able to bring up the terminal and had a GS of 8 and a GE of 4 saying that it was trying to home, again no motors. VE returned Version 2.2. After looking through the easycomm module I noticed that a command of RB would perform a re-boot. After issuing RB, I could hear the motors hum and the Arduino went up in smoke.

Hank - wz3hmt

Hey, take a look at wiki.

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Yes I read that and broke down and bought some from Spark Fun. I will try those and let you know.


I picked up some 5V arduino pro mini’s and used one of them. Unfortunately trying this the ferrite bead FB2 went up in smoke and took out part of the trace.

For the heck of it I bridged the trace using a sort lead and bypassed the FB2.

That caused the 5V arduino pro mini to go up in smoke.

Fortunately I had ordered 2 controller boards initially and the 5V pro mini’s were compatable units. I have since received original sparkfun 5V pro mini’s.

What confuses me is the FB2 had a good 11.9V coming out of it. What is drawing so much current through the PI to smoke these components?

I checked for sorts prior to installing the arduinos and Pololu 8825’s. Should I switch back to the A4988’s for stepper motor controlers?




after building a second controller, it is working now. Not sure exactly what I did wrong, but I am good now.

hank - wz3hmt