Speeduino – V0.4.1 Assembly

As if one Speeduino wasn’t enough, I built another.

Like all good geeks, I just can’t help myself when it comes to playing with things. When I purchased my original Speeduino i actually purchased a few of the o.3.3 boards, and enough components to build a pair of them. I sold a couple of the boards, spreading the Speeduino love, and decided that instead of building another identical 0.3.3 board, I should go the other way, build the other model, a 0.4.1.

Most people wouldn’t bother, they would build one, or the other and be done with it. Not me, I had to have both.

On paper they look kinda similar, and they share the majority of their components, but the 0.4.1 board has some added features the 0.3 doesn’t have. It’s smaller so is easier to fit into cases, all IO is moved to a single 40 pin connector which is much cleaner, and it has a space to fit a stepper motor driver for stepper idle valves. These features were enough to make me want one.

What an experience it was too!

So obviously i started with a lovely, clean board. This one is black. Flash.

And then start adding bits to it. With my latest shipment of components from Digikey I also picked up a couple of new tools. One was a set of nice needle nose pliers, something I have been missing for a while, another was this awesome component leg bending tool. Makes all your components nice and uniform, and it takes piss all times to bend the legs.

And from there, I stuck more and more bits on until the board was populated.

And then it all went wrong.

Upon initial testing it was obvious something was wrong. Tunerstudio was reporting the voltage as 24v, even when only being fed 5v from USB! It also wasn’t responding to Ardustim input, and LED5 and LED6 were constantly lit. It wasn’t happy.

I posted on the Speeduino official forums about my issues, and a helpful chap whose very first post was to tell me what the issue was and how to fix it, come to my aid. As it turns out there was a bad batch of boards, where the ground plane wasn’t connected correctly, leading to a whole bunch of grounds on the board, not grounded. Josh, the project dev gave me a couple of things to test as well.

After work I got cracking on it. Testing what I was asked to, with no change. I decided to bite the bullet, check all my grounds, and then add in bridge links to join them up.

This was my test “bench”

And this is what I was working on. Every red spot is a ground point. All of them should tie back into the main ground point. Only some of them did.

Once I tested them all, this is what I was left with. Every blue box is a ground that wasn’t connected.

Needless to say, that wasn’t good. It’s no wonder it was throwing a wobbly. The next job was to link them all back up. I got stuck in, using scrap hookup wire, where I stripped out a few strands, twisted them and soldered them to the relevant points on the board.

Its ugly, but its functional. It won’t be seen under the Arduino, and in the case anyway. I’ll probably hot glue them when I put it in the case, just to protect and insulate them.

So with the bridges installed, I went back to testing. First issue was that it appeared I had ground continuity on the 5v points in the proto area. Upon discussion with Josh via IRC chat, we worked out that it all must be working OK, as I was getting the right voltages, so we decided to overlook that. The other issue was that when Ardustim was connected, LED7 would light up and stay lit. That turned out to be a complete fail on my part, the IDC 40 pin breakout cable I was using was labelled wrong.

Removed that cable, wired direct to the correct pins on the IDC connector, and nothing. No RPM or LEDs. Oh well, I guess it’s better than the solid lit LEDs I had before. This also turned out to be a complete fail on my part. At some point during testing, or building, I installed the trigger setting jumper on JP3 instead of JP2. Once the jumper was moved over, it all fired into life and was doing as it should. I guess I should really stop troubleshooting things when im tired.

So all in all it was a success. Bit of a faff around, but Josh made a huge effort to make sure I could get the board going, even if most of the faults were user error. Having direct contact with the main developer of the project is one thing that really makes this project special.

Oh yeah, and how much smaller is the 0.4? Small.

So, for now, that’s it. I don’t have a car to fit anything to, and I can’t proceed any further without one.

Stay tuned, things are happening in the background and progress will happen soon.