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MicroSquirt® Tooth Analyzer

If you want to see what the processor sees for cam and crank signals, you can try the code/application below.

The S19 embedded code file below is downloaded (using the downloader) into your MicroSquirt® or MS-II™ in place of the existing code. It WON'T RUN the car - its only purpose only to look at the cranking pulses. You can leave your existing wiring intact, close MegaTune, and don't worry about INI files or MSQ files - this code doesn't use them.

The Windows 98/Me/XP/Vista application (tachref.exe) is then run on the tuning laptop, and doesn't need to be installed (just double-click on the executable file).

You need to download two sets of code:

First save an MSQ file of your current settings for your code. Then do the following:

  1. Bring up the tachref application (double-click on tachref.exe),
  2. Set the proper com port for your serial connection. You have to do this each time you restart the application. Unlike MegaTune it is not remembered in the tachref application,
  3. Power up your MicroSquirt® controller,
  4. Start cranking and hit the Run Test button to record the tooth data. You can hit the Run button first, but must start cranking within 2 secs or the test will time out and you will have to hit the run test button again,
  5. The data will stop being collected when greater than 3000 bytes of data are collected or you stop cranking for greater than 2 seconds. The processor then sends the PC application the data for the cam and crank signals and this is plotted in the graph on the application window.

You can change the background color, toggle the grid on/off, and edit the two signal line colors using the buttons near the bottom of the application.

The embedded program comes up in a state where the fuel pump, injectors and ignition should all be off, but CHECK to make sure that is the case (so you don't fry a coil or low impedance injectors, etc.). Note that if you are using this on a stim, this will mean you won't have any LEDs to tell you if the power is on or off.

The program captures data from both 'input captures' (i.e., the rising edge and the falling edge), but it only sees edges, not amplitudes. However, the processor (and its embedded code) itself only sees edges as well - so what you are seeing is exactly what the processor is going to act on.

When you are done testing, just reload your regular code (.S19) and settings (.MSQ).

MegaSquirt® and MicroSquirt® controllers are experimental devices intended for educational purposes.
MegaSquirt® and MicroSquirt® controllers are not for sale or use on pollution controlled vehicles. Check the laws that apply in your locality to determine if using a MegaSquirt® or MicroSquirt® controller is legal for your application.
©2008 Bruce Bowling and Al Grippo. All rights reserved. MegaSquirt® and MicroSquirt® are registered trademarks. This document is solely for the support of MegaSquirt® boards from Bowling and Grippo.