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MegaSquirt-II Serial Communications

MS-II™ Serial Interface Description

MegaSquirt-II uses a baud rate of 115200 to communicate with the tuning software. Communication is established when the tuning software sends a command character - the particular character sets the mode:

The primary commands for sending and receiving data from MS II via the RS232 serial connection are all constructed using 3 initial bytes as follows:

  1. one-letter command: The possibilities for the one letter command are:

  2. <CANid> - a binary integer single byte from 0-15. Use 0 for MS-II™, for other (GPIO) devices it is arbitrary depending on how a user has configured the devices in his network. Just set to 0 for communication between the PC and MS-II.

  3. <tble_idx> - a binary integer byte from 0-15 that specifies the block of data from which to get/send data. The variable blocks in MS-II™ corresponding to <tble_idx> 0-6 (only ones at present) are as follows:

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©2004, 2012 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.