Microsquirt with 5 volt serial comms?

[Greg_E]

Will the microsquirt work with 5 volt serial comms? I'm building a Bluetooth to serial adapter for a Buell motorcycle and eventually I would like to use this same adapter with a Micrsquirt on this bike. The Bluetooth module is 3.3 volt comms, with a voltage divider on the RX line to drop the 5v to around 3.5v and a MOSFET to jump the TX 3.3 up to 5 volts. It is an asynchronous data scheme with 9600k baud rate, but I can change the RF module to any other rate through software.

I just read a little about the Microsquirt and see that is has some form of MAX level shifter installed, will that shifter take and give 5 volt signals? Should I plan on pulling the MAX chip out to run the 5 volt signals?

[Bruce Bowling]

Microsquirt works on RS232 signaling voltages using MAX3221 level converter - you will need to use a level converter to get this back to logic level signaling.

- Bruce

[Greg_E]

Thanks, I'll have to build an adapter circuit with another level shifter like another MAX chip. As I get closer to this project I'll have lots of questions about getting MAP and cam sensor signals from the motor to work with the MS controllers. It's an odd fire 45 degree v twin similar to a sportster, keeping as many stock sensors as possible would be great. I need to do more research on the stock system before I start asking questions though.