AVC ’10 Posted at: Sat, Apr 17th, 2010 | 6:48AM UTC By Josh Ashby

The Sparkfun Autonomous Vehicle Competition is TODAY! Read more…

BOB update Posted at: Wed, Mar 17th, 2010 | 4:55PM UTC By Josh Ashby

Half the time, something works, the other half of the time it doesn’t, and the other half of the time, it just goes up in smoke. As such was the case with my V1.5 Rev. 1 quad motor controller. Read more…

Revision 2 of Quad Low-side “Taco” Posted at: Wed, Mar 3rd, 2010 | 7:51PM UTC By Josh Ashby

So I finally got around to fixing a few things, and cleaning the board up, here is BOB’s newest working version of his motor controller board. Read more…

New Board, New Parts Posted at: Sat, Feb 27th, 2010 | 4:35PM UTC By Josh Ashby

So I finally got around to getting a board designed for Generation 3 electronics, but like everything else, being the first prototype board there were some things left out and other mistakes.

Also the Code has been updated, please check it out at: http://github.com/JoshAshby/Robotbob/tree/experimental

Read more…

Success! Posted at: Mon, Feb 8th, 2010 | 8:56PM UTC By Josh Ashby

After several hours of research going deeper into the motor controller designs that my current Generation 3 electronics is based off of, I have finally found a few things that i can add for safety to my design, and a few suggestions to try in order to get the design working. First thing that I saw suggested a few times was adding a cap across the power lines, and while this is something I normally do, I forwent installing them this time for simplicity of the design, so I added a 1000uF 50V cap, and have a 10uF ready to go if needed. this cap is for voltage drops when the motor first kicks in.

Second thing I saw suggested a few times also was the use of a 12V zener diode between GND and the output line of the TC4424CPA mosfet driver. this diode is for power spikes, only allowing 12V or less to exist on the output line.

Finally someone suggested that the mosfet driver was burning out because it was being forced to drive a failed mosfet, so I stuck a brand new mosfet into the system, and BOOM it works perfectly, no over heating of anything, and no magic smoke went along with perfect results, now all that is left is a PWM ramp up, and ramp down test since this is a motor controller we’re talking about.

Generation 3 Electronics Posted at: Sat, Jan 23rd, 2010 | 11:19PM UTC By Josh Ashby

Good news for BOB
I ordered a few MOSFET drivers, and extra MOSFETs for BOB to test out and hopefully solve the problem of having no control over the motor controllers right now. The MOSFETs are still the same old IRF540N’s and the drivers are the dual 3 Amp TC4424CPA drivers. Read more…