Spudmn's Puma board build

[Spudmn]

I did notice that on one setup the whole wave form got inverted. like the Xor had changed state. That didn't make sense. It might help with debugging.

D'oh I noticed today that I had soldered on both the pull up and pull down on the XOR. This caused 2.5V on the input and caused the out to flip flop at will.

[Fred]

And so hw designs develop, three pads = that's not possible :-)

[Spudmn]

I changed the ignition driver to 12V. Here is the circuit. I still want to add an LED.

[Spudmn]

Bench testing video

http://www.youtube.com/watch?v=m7F-mtqDtKc

[Fred]

Note that R30 creates a voltage divider network, and although it's 100:1 it's a bit ugly, I think I removed mine, as it's not strictly necessary anyway, and when used should be on the other side of the 1k. Otherwise fine :-) I can't comment on the correctness of the pull up/down on the XOR, but if you're sure that it's happy and dwelling for a short time, pausing for a long time, then I'll double check it and get it added to the docs :-)

[Fred]

Spudmn, make sure you grab the latest from the dev branch before turning the key again! It has a major fix in it which you need! Good luck getting a nice video of engine number 8 for us! And congratulations on the achievement! :-)

[Fred]

OK, definitely all fixed now, just checked, my mistake in config, woops! Woo hoo, number 9 is just around the corner! :-)

[Spudmn]

I needed a way of timing my set up before I tried to start the engine. I don't have a timing light yet and I only had a logic analyser.

I wanted to know what timing the distributor had but I couldn't feed 12V into my LA. I had an RS232 to TTL board on my shelf. It's just a ST202 chip and caps. I wired the RX in to the points and RX out to the LA. Worked like a treat, converting the 12V signal from the points to 5V for my LA. The output was inverted but I didn't care.

Running the engine with points and distributor I could then compare the points to FreeEMS. I configured it until they matched. This is only a very rough set up at one RPM and Load and I will need to time it properly.

I might use this method to to capture the advance curve of the distributor.

[Fred]

You forgot to post the vid that you uploaded. I hope there wasn't a reason for that, so I'm going to do it for you, don't kill me.

http://www.youtube.com/watch?v=3GM56iAK59M

Very cool mate! Congrats!

I downloaded one of the files overnight - FOUR HOURS lol :-) Will grab the other one later today and try to do something with it, though my computer/net situation here is not good.

Fred.

[Spudmn]

I managed get a timing light working and checked that my trigger wheel was timed correctly. It was. By luck I didn't need to add any offset in the code.

I set the advance curve to flat 10 Deg and checked the timing with a scope while still running on the distributor. Every thing looked good so I fired it up again on FreeEMS.

It started up fine and ran very smooth. My distributor was runing a lot more advance than 10 so I changed the curve to flat 15. Fired up and ran better.

My next question is how do I work out the advance curve I need?