[turboedge]

So, I got impatient waiting for parts to make it to my house from the far reaches of the planet and I started drawing a smaller version of the current official Speeduino boards. It is mostly a v0.4 with accessories removed, resistor networks/arrays, 2 injector and ignitor channels. I wanted to have it fit within the confines of the mega board and still use through hole parts to make it easier to assemble like the original Kartduino. The connectors are Molex KK254 (like computer fans). Since my first project is to be a small engine I thought a design like this would work well.

This is my first time using KiCAD or drawing a board. So what do you think? Will it work? Suggestions? Thanks!

[noisymime]

As far as the electronics go, if it's based on the existing schematics and you have implemented them faithfully, there's absolutely no reason at all why it shouldn't work

Definitely let us know how it all comes together!

[turboedge]

Is the TC4424A a suitable replacement for the TC4424, or would it require adjustments to the design? The datasheet indicates that it is a pin compatible newer revision with what appears to be better specs. Digi-key indicates that the old version is not for new designs and the newer "A" version is cheaper.

Thanks!

[turboedge]

I have officially made Swiss cheese . I sent this to manufacturing. In my excitement I forgot I wanted to update the silkscreen to include TAPR . If anyone wants any part of this let me know, I will get it to you.

[ElDominio]

I love this.

I've considered also slimming down the code and making it run on a Pro Mini , which would make the package size considerably smaller and cheaper. I'm keeping tabs on your thread, and this really motivates me to start yanking code off Speeduino main code and make it not work correctly! lol

[noisymime]

Is the TC4424A a suitable replacement for the TC4424, or would it require adjustments to the design? The datasheet indicates that it is a pin compatible newer revision with what appears to be better specs. Digi-key indicates that the old version is not for new designs and the newer "A" version is cheaper.

Yep, no issues at all with using the A versions of these parts.

[turboedge]

Thanks for the kind words ElDominio! I think you have your work cut out for you shrinking it down to the pro mini's 32K, but if it can be done I think it would be great for small engine applications. I confess I have still not even fired up the mega to see what's what, and this will be my first Arduino project. I've been wanting to do a controller project for a while, could not decide what to do. Then I found this, computer controlled engines !

Thanks noisymime for verifying that for me. I thought that would be the case, but I could not find a for certain answer anywhere. Love the project. Thanks for all the effort you have put into it!

Now I must wait . Hopefully not too long. I keep thinking of more tweaks to make to it, but it's locked in now. Maybe release v0.1.1, if there ever is such a thing. Now I have to figure out what hardware to use for my application, gives me something to do while I wait I suppose.

[turboedge]

Had some issues with v0.1, will post pics of assembled board at some point.

Here is v0.1.1 mostly finished, I think.

[turboedge]

As promised, assembled pics of v0.1 where you can clearly see the issues. The stepper module is unusable due to interference with the USB connector. The other issue is with my use of the AMP crimp-less connector and the height of the MOSFETs. It will work for my single channel, no stepper required needs though.

I will continue to tweak it until I find the results acceptable and then I will post the files here.

[PSIG]

Looks good though! Perhaps just move the stepper to the MAP location, and put an MPXH6250 over the USB. They are big enough to solder by hand. The TO-220 height may not be a problem, as the wires need radius space to turn 90° anyway?

David