MegaSquirt® Electronic Fuel Injection Computer by Bowling & Grippo

MegaSquirt-I™ Embedded Software Download

For MS-II, see:

The embedded assembly code for MS-I, include files, and development tools, can be downloaded here.
To save any of the files below, right click on a link below and 'Save As':

This is the latest assembly source code for the MegaSquirt-I™ system - Version 3.00.

Download the MegaSquirt-I™ Assembly Source Here

This is the latest assembly source code header for MegaSquirt-I™ variables.

Download the MegaSquirt-I™ Assembly Header File Here

This is a .zip file of all of the supporting MegaSquirt-I™ files, including latest bootloader source (with bug fixes), MAP and thermister table lookup files.

Download the MegaSquirt-I™ Assembly Support and MAP/Temp Lookup Table Files Here

This is the resultant s-records for the assembly and link of all of the above files - this is the file that is downloaded into the MC68HC908GP32 by the bootloader.

Download the MegaSquirt-I™ megasquirt.s19 File Here

Here is the full P&E assembler/linker/simulator/IDE which can be used to assemble, link, and program the MC68HC908GP32 microcontroller with the above files.

Download the P&E Assembler toolset here (zip file)

Bootloader Download Instructions - Hyperterm

Here are instructions for using Hyperterm.exe for updating the embedded software (all Windows installations has the Hyperterminal application - use a "find-file" function to search for "hypertrm.exe"):

  • For Version V1.01 boards, short out the bootloader resistor (R6) on the board, for Version 2.2 put on the Bootloader jumper pin, hook up a serial cable from the computer to the MS box, and fire up Hyperterminal (Hypertrm.exe). You do not use the PC Configurator to perform the firmware upload - this is done with the terminal program Hyperterm (or similar, see below), and do not have PC Configurator, TunerStudio, MegaTune, or any other serial data application running on your PC. At this point, leave the MS unit unpowered.

  • You will see a Hyperterminal screen when you execute - type in any name you want in the box, and make sure the Red telephone with the little yellow telephone next to it is highlighted.

  • Now, a new screen appears. On the "Connect Using" selection, select either COM1 or COM2, depending on your serial connection.

  • New screen with comm port settings pops up. Select 9600 baud, 8 data bits, no parity, 1 stop bit, and set flow control to "None" - this is very important.

  • Hyperterm terminal screen is now up. Apply power to the MS board, then hit . You should see the "Boot>" prompt appear in the terminal screen. Type "H" and you will be shown the options available in bootloader mode.

  • Hit "W" for "Wipe" - this erases the entire flash array (except the section running the bootloader).

  • Hit "P" for "Program," which will respond with the text "wait ...". Then under the "Transfer" menu, select "Send Text File..." (do not use the "Send file" mode - you are sending a text file). Set "Files of type" to "All files" and select the .s19 file containing your assembled code (megasquirt.s19).

  • You will see no activity on the screen for about 40 seconds. Then the prompt will come back, which means the operation is finished. Turn off power to MS and shut down Hyperterminal. Remove the jumper, and you are ready to go.

    Bootloader Download Instructions - OC Console

    Here are instructions for using the program OC-Console for performing the firmware upgrade. This program does the same thing as Hyperterm, but has the advantage of pausing 50 milliseconds between S-record programming, which may help those who experience problems using Hyperterm. OC-Console is also from Denmark, so you may get to do a little language translation (its good for you!):

    Note that the OC Console is an obsolete application. Use Eric Fahlgren's downloader instead:

  • Download the OC Console Application Here. Unzip in any directory you choose. Also, put the S-record file to be downloaded in the same directory as the OC Console Application

  • Run the OCConsole.exe application. You will see a simple window appear. Click on the "Einstellung..." button on the top. Select the "Schnittstelle" tab option, and select the proper COM port for your computer, Baudrate of 9600, Paritat of "keine", Datenbits of 8 and Stopbits of 1. Now, hit the "Terminal" tab and select ASCII. Now, click the "Dateitransfer" tab, and select the option of "Verzogerung vor jerder Zeile (50 ms)". Hit "OK"

  • Hook up the bootloader jumper (see the hyperterm example above), connect the serial cable, and power up the MS box, and hit . You will see the "Boot>" prompt.

  • Hit "W" for "Wipe" - this erases the entire flash array (except the section running the bootloader).

  • Hit "P" for Program. Now, click on the "Transfer..." bix on the top and type in "megasquirt.s19" in the entry box, and hit "OK". You will see a progress bar come up on the screen. When the transfer is complete, unplug the MS box and unhook the bootloader jumper, and you are set to go.


    © 2003, 2008 Bowling and Grippo. All rights reserved. MegaSquirt® and MicroSquirt® are registered trademarks.