Bug? 60-2 = 20-2?????

LucasSchneider · Post by **LucasSchneider** » Fri Oct 26, 2007 12:39 pm

ONLY set a dipswich 4 ON -> 60-2

and with tooth logger, i get this, no as 60-2 whell

any idea to solve this?

LucasSchneider · Post by **LucasSchneider** » Fri Oct 26, 2007 1:06 pm

dipswitch

LucasSchneider · Post by **LucasSchneider** » Fri Nov 09, 2007 1:02 pm

i scoped the signal....its ONLY 20 tooth...............................

racingmini_mtl · Post by **racingmini_mtl** » Fri Nov 09, 2007 8:37 pm

From what I can see, you're trying to run at about 12000RPM (about 5ms from gap to gap). The 60-2 signal cannot be run at more than about 9500RPM. After that, the JimStim CPU can't handle the signal. Try lowering the RPM below that and you'll see the correct 60-2 signal.

Do you need to test your MS at that high RPM? Have you tried with a lower RPM? With most wheel modes, you can go up to 16000 RPM (with both RPM pots turned all the way clockwise). The 60-2 signal is one of the few exceptions where you can't do that but if you limit the RPM under 9500RPM you should be fine. Most people will be satisfied to test their MS up to that RPM because their engine will not go above that.

Let me know if you still have problems at lower RPMs.

Jean

LucasSchneider · Post by **LucasSchneider** » Sun Nov 11, 2007 4:30 pm

low rpm

Post by **jsmcortina** » Sun Nov 11, 2007 5:07 pm

See attached image of my Jimstim with 60-2 output at 8400rpm. Scope is 1ms per div (but somewhat flaky at the moment.) Lower trace is ignition output from MS2.

EDIT: You can't see the divs... The total trace is about 8.5 divs long. Even though the picture is blurry you can see the correct waveform.

I also tried down at 220rpm and the pattern looks good there too although too dark to attempt a photo.

James

racingmini_mtl · Post by **racingmini_mtl** » Sun Nov 11, 2007 6:04 pm

Lucas,

I don't understand how you can get this signal because, as James, I get a very good 60-2 signal.

Where do you take your signal from with the scope? Do you have anything connected to the JimStim? Have you looked at the signal directly from the JimStim CPU?

By the way, from your signal, you're probably AC coupled and not DC as you should (not that it would change the number of teeth).

Can you try the 36-1 mode to see what you get? You just need to have DIP switch #3 on instead of #4. That might gives us a clue what's going on here.

Jean

GintsK · Post by **GintsK** » Mon Nov 12, 2007 3:27 pm

I think i have problems with 60-2 too. Never got it running. Was forced use waw file and soundcard - jumper system is good.

I will try it to describe it with scope shots. IIRC 36-1 did not work too.

Post by **jsmcortina** » Mon Nov 12, 2007 4:05 pm

That is really strange. Now while I don't necessarily have precisely the same code or hardware version as the released JimStim, I'm using those wheel modes all the time and compiled the latest code up for Jean.

If anyone in Europe has this problem you can send me your CPU and I'll test it, reprogramme if required and return it for free.

Although thinking about it, you'd want to check out the postage cost from you to the UK.

James

racingmini_mtl · Post by **racingmini_mtl** » Mon Nov 12, 2007 4:33 pm

After discussing this with James, it seems that you may have a short that grounds DIP switch #2 which is actually the same CPU pin as the RX pin. With that grounded you would get a 44-2-2 (which looks like 20-2) instead of the desired 60-2.

If you could check the voltage at the RX pin besides the CPU that would confirm it. If you see that it is at 0V then that's the problem because it should be at 3.3V if DIP switch #2 is OFF.

The cause could be a solder bridge somewhere or a faulty DIP switch. If you can check the voltage and the soldering and get back to us we'll see how to correct this.

Cheers,
Jean

racingmini_mtl · Post by **racingmini_mtl** » Mon Nov 12, 2007 4:54 pm

I just thought of something. I can't see from you picture but make sure that D3 is correctly installed. The black line needs to be towards the DIP switches. If it is on the other side that would ground the CPU pin.

Jean

LucasSchneider · Post by **LucasSchneider** » Mon Nov 12, 2007 6:05 pm

hi!!!
i REMOVED the D3 and now its function NICEEEEEEEEEEEEE!!!!!!!!!!!!

:):)

GintsK · Post by **GintsK** » Tue Nov 13, 2007 2:16 pm

Solved!!! D3 was my problem too. It keeps low 1.6V potential. It was russian Zener diode. Currently I remove it. As I understand low voltage Zeners is imprecise at low currents. Right?

I see latest BOM is changed and there is no need for D3.

Thanks!

Gints.