Question SMC 3 Arduino and Moto Monster Board failures

Firstly would like to thank the developers of SMC3 code and Windows Utilities, and for those who shared wiring diagrams.

I am sitting with a bit of an issue: Below you see the circuit board I designed

based on the following diagram (Two MotoMonster for two motors.jpg)




I am running SMC3 firmware in MODE1.

As soon as I connect power to the Arduino USB port and apply 12V power to the MotoMonster, the Arduino 328-P chip itself burns out, or the FTDI controller on the board burns out almost instantly. The strange thing is, I built this on a vari-board previously, and it worked no issues. One of GND tracks also burnt out in the process, hence why there is a new soldiered GND wire on the board.

Could someone on the forum pls have a look through with a fresh set of eyes and see if I made a mistake somewhere? I just can't find it (Pls excuse my signature on the copper side, was my first ever pcb etch).

Thanks,
Shaun

In the post above, there is a zip file with a fritzing fzz file. This is the board circuit diagram

the diagram is correct in post 1

I suggest trying to get them to work 1 at a time hardwired to eliminate wiring faults as a cause.. its hard to follow your board from a pic.

Connect all data common ground for all the boards ... don't just use this one Arduino ground connection and let the current pass through the Ard. layers [use both grounds on both sides of the Ard. ] ...


Just connect another wire here for the new UNO ...

what happened with these tracks ? are they burnet with the Arduino too ?
Or you have a shorted pot ? bad etching copper layer ?

@speedy and Bruce, thank you very much. I will give this a try tonight. To answer your question Speedy, it's a bad copper etch

So i re-grounded as mentioned above. same issue, arduino blown. back to the drawing board. I also changed out the moto monster boards for new ones on this test. very frustrating as I had this working perfectly on a Vari-board. I'm starting to think if one of the motors or pots are bust.

sure it is ...

Edit : A quick question ...
Have you loaded the SMC3 code to the new Arduino before testing ?

Why ? ... because the code correctly assign the output pins for the blank Arduino so there will be no Shoot Through in the MMs .

first thing I did was load SMC3 on the board. then, opened the utilities software, made sure there was a connection, applied the 12V power to the MM from the car batt, and poof, ard blown. Is it Possible to pls have a look at the fritzing file which i attached right at the top?

Actually I use Sprint-Layout 6.0 and it cannot import the .fzz file ...

And I can see your board clearly following the correct connection and I verify that to you by the next photo except for that mentioned extra ground connection to be used ...

I just need you to have a close look to the gap [Yellow arrow ] between each 8 pins of the MMs and verify that they are taken in consideration correctly ...

Plus verify that those connections marked in [Red circle ] are shorted together ... gap is included in one of them .



Good luck ...

Thanks Speedy. So, i got it working last night, albeit for 10mins, i manually drove the pot passed its max limits, and the arduino popped. I did tune the PID according to the manual. is there anychance the PWM Max setting could draw so much current it just fries the board?

No way ... the SMC3 code shuts down the PWM when the pot reaches the max. limit ...
I guess it is a shorted pot then .
Have you checked that MM connections in the above picture ... I can't see a clear gap between the pins .

Hello, it's been a while...

So in this pic, you'll see we re-designed the board, with a voltage regulator and 4050 non-inverting hex chip for protection, new pots, and had it professionally printed to avoid errors. Basically there is a common ground from the PSU (in this case a bench PSU for testing), going to the Arduino, the pots and two moto monster boards.

Then 12V power to the moto monster boards, and a seperate 5v through the regulator going to the +5v of the Moto monster and pots. So far plugging SMC is working well, and nothing blown. hope to test this weekend on the rig.