Page 1 of 1

Microsquirt playing dead after sitting on shelf

Posted: Wed May 23, 2012 6:59 am
by rb855
Hello,
Sorted through pages of posts and theres a few similar results but not close enough or never fixed. I have been working on a joint project of building a 3cyl 2stroke streetbike that we have added reeds, FI, and electronic spark (amongst much more). A couple years ago I had the micro hooked up to basic sensors on the bike and fooled with settings and such to familiarize myself, and everything worked perfectly. I am using the same laptop and same (Prolific?) usb>serial adapter.

The trouble is, Yesterday I tried to connect to it with no result. I have isolated it from the bike giving it good power and ground, tried a second serial cable, tested the Vref, and all per the comm diag procedures. I have confirmed the serial port. Tunerstudio claims no firmware, even though it had a working load on it. I tried updating to the newest firmware using the MS-II download utility, it seemed to work fine. When I use MS-II downloader to read the signature it returns "<a<" every time. I then accidently discovered that it will complete a firmware update WITHOUT grounding the bootloader wire. It completes and passes the verification mode also. On the rare chance tuner studio finds it on auto detect the Detected Firmware field is blank. Im totally scratching my head with this one. I tested my port connectivity (using same serial cable and adapter) with a LC-1 wideband controller and it works flawlessly.

There is a 1% chance that the Vref contacted 12v for a fraction of a second at one point, but I cannot confirm or deny if I had power on that wire at the time, and if contact was even made. When the unit is powered up, theres no outputs, no FP, nothing. I do have a scope, and plenty of electronics experience, Any place I should go right to and start with? Sorry for the long wind, wanted to cover everything I know.

Thankyou for your time!
R

Re: Microsquirt playing dead after sitting on shelf

Posted: Thu May 24, 2012 4:24 am
by Matt Cramer
This sounds like the processor is damaged if it's stuck in bootloader mode.

Re: Microsquirt playing dead after sitting on shelf

Posted: Thu May 24, 2012 5:12 am
by rb855
While waiting on my post to be approved I did some poking around.
I started with the Max3221 serial interface. Pulled out the scope and started poking around expecting to find some communications.
Vref is at 5.01v
Pin8 RXout - 0.0v
Pin9 RX - 0.0v
Pin11 TX - 4.99v
Pin13 TXout - 0.0v
No signal, only steady state voltage.

I proceeded to check the processor MC9S12C32
Pin - Use - Volt
5 - VDD1 - 2.51v
6 - VSS1 - 0.0v
11 - MODC - 4.93v
17 - Reset - 4.89v
35+36 - Vdd - 4.98v
38 - RX - 4.97v steady
39 - TX - 4.97v steady
44 - CanTX - 0.14v steady
45 - CanRX - 0.74v steady
47 - VDDX - 4.97v

The harness is still attached to the bike and I dont have a serial cable to hack up to test connectivity on the bench. These tests were performed using a 12v SLA battery that was not on a charger, with no sensor or loads attached to the micro, effectively isolated. All injector, igition, FP, and LED outputs were off. Would I be proper to assume the processor is caput? SMC work is a little out of my realm, but if I were to attempt surgery, is the chip available, and is it drop in or require special programming (eg through BDM port?). I am not able to test the crystal with my scope as its a 1mhz lab scope.

Thankyou for your time!
R

Re: Microsquirt playing dead after sitting on shelf

Posted: Thu May 24, 2012 8:30 am
by mfro
is the chip available, and is it drop in or require special programming (eg through BDM port?)
The chip is available (Digi-Key, for example) but you'll need to get at least the bootloader on the µP flash, which requires - to my knowledge - a BDM cable and proper software.