MpGuino compatibilty issues
 

For those of you looking to build one if you have an alternator bypass switch. It will cause Guino to restart losing tank and current memory. Happened to me 3 times today, I am going to remove alternator switch. Or figure out how to fix it.

Next problem do not hook up a injector kill switch it will cause guino to lock up. Kill you ignition instead. This happened to me 4 times today before figuring out what was causing it to happen.

Just a few things to watch out for.

I am not sure where you are getting the guino power from, but you should be able to go straight to the battery and eliminate any chance of interference from the alternator kill switch.

And rest assured the guino does not lock up a metro with the cam signal kill switch. But an injector switch can "fool" it into giving false readings, or worse I imagine. I might try a 10k resistor across the switch/relay to hold the signal high but not give enough current to open the injector (assuming your switch is in-line with the injector). Obviously lots of creative ways to kill an engine :) I can't cover them all.

I am going straight to battery power.Alt. kill causes enough of a voltage spike to reset unit. Maybe a capacitor on the battery feed would solve this. I am just going to remove my alt. kill and put in lighter battery.

Would a dedicated battery for 'guino work? A big enough battery should last at least a tankful (which is the point of having continuous power).

BB, can you describe how you are going from 12 to 5 volts on your extremely handsome guino? :)

I built just as schematic shows by using 7805. I take you saw the pictures of it, Thanks. I tested output of 7805 using my power supply and shows a good 5v supply.

If you have any larger capacitors laying around (or can salvage one from an old power supply or something) I might suggest putting it in parallel with the 330uf with some alligator leads as a test to see if that fixes it. The smallest one that does the job should minimize the wear and tear on that diode.

The metro alternator is a one wire? Can you expand on the alternator disconnect system a bit too?

Thx,
Dave.

The alternator disconnect uses a 70 amp Potter Brumfield relay to break the output to the fuse box. The main feed (and field) wire it is like a 10 or 8 gauge wire.

I will try a 470uf I have laying here, I may have a couple larger ones can't find them right now.

Alright well I used the 470uf in parallel with the 300uf cap, fixed reset issue.

Switched to coil kill instead of injector kill, fixed lockup problem. (My 91 doesn't have a cam sensor so couldn't use your idea dcb.)

Now I have another issue, I tried some eoc, p&g today and that causes a reset. I think I am still getting a voltage drop that causes this issue. I am thinking about putting my old 1 farad cap from my car stereo days under the hood and hooking up to battery feed.

I figure if this is having issues with p&g what does it do to my ecu. It probably doesn't like the voltage drops/ spikes either. I figure it would be cheap insurance in my case to just help smooth the voltage to everything a little.

EDIT: Well I tried the 1 farad on the main lead from battery to fuse box, no help. I am going to go for drive again and see what I can figure out.

Please help!! Feeling lost.
 

Alright I am still having issues on this.

1. resets itself when EOC, but not everytime.
2. random lock up when it resets like in #1

Things I have done to correct this.
1. added a 470uf cap in parallel with the 330
2. put a 1 farad cap on main battery feed to underhood fuse box.
3. installed a 2ah 12v battery under dash that is hooked up to vehicle via a current limiting resistor and a diode. Thus eliminating voltage drop from vehicle, was trying to see if voltage is cause.

The other thing I have noticed is sometimes the cpu monitor shows random %'s like 775, 547, 180, etc. I have reloaded ver. 73 a couple times to make sure it copied correctly. Checked the shield I built multiple times. I am wondering is maybe the 7805 from radio shack is acting up, running out of ideas.

Could it be the vss delay being set at 3?

I love having it works great when driving normal, but I hate to drive normal now.

I appreciate your perseverance. Can you try the separate battery trick thusly:

Connect spare battery ground to vehicle ground.

Connect spare battery + and ground to the guino 12v input.

connect vss and inj as normal.

See if that helps at all.



Also Did you change vssdelay to 3 to fix something?

FYI, The high cpu numbers are only when you use setup. It clears back to normal at next power cycle.

Set vss to 3 to see if would smooth mph reading, will set back to 2.

I was sitting here thinking, would putting a little larger cap on output of 7805 help smooth out the 5v signal? I took it for a drive and a lot better now. Did not do the spare battery separation. I just think maybe replace the .1 uf with something a tiny bit larger.

I cleared the eprom and reloaded everything, instead of just code. It helped it out some.

Alright it is fixed!!:thumbup: Thanks for the help.

After resetting everything including eprom, it has went several eoc cycles and no reset. I still think it was voltage spikes causing this to happen, the added bonus of backup battery is I can disconnect main battery to work on car and not lose any memory on guino.

Now to fill tank so I can start with fuel pulses. I wonder what people will think when I only stop for like a 20 second fill up.

sweet! Thanks BB I'll have to think about some more capacitance and another diode or two before putting in the pcb order.

Yeah, would be a good idea. Some people would not like to troubleshoot as much as I do at times.

Edit: Will this pcb you are talking about be for iduino? or a stand alone unit on its own? USB capable?

Well it locked again.:mad: :confused:

Could it be a heat issue it was warmer today than yesterday, when it locked 7805 was pretty hot to the touch. Not enough to burn ya but a lil uncomfortable.

I remember seeing someone had a problem with transistor/ dimmer circuit. What were those symptoms?

Good news though 8479 is exact on vss.

Hey how would you hook up the iduino mpguino straight to the battery? I was just wondering do you just attach a cable from the positive end of the battery to the 12v on the mpguino and then the negative to the ground or how would you do it?

I used ECU battery and ECU ground. Check your pinouts to see if that's feasible. Keep in mind you must use constant power (that doesn't die when you key off). That way it can keep your tank data. You can also find a wiring diagram for your radio. Radios generally have a constant-on power lead in order to keep station presets, etc. Hope that helps.

I have a 1993 geo metro. If I hook up my stereo and the mpg to the same wire that is supposed to be for the stereo 12v constant would that cause any issues? Thanks for helping.

It shouldn't. Keep in mind that's what I'm doing with my ECU (both the ECU and the 'guino are powered from the same source lead).

Awesome dude thanks I plugged it in but then the ICU(?) got extremely hot to the point that it burned me. I know this is probably mentioned somewhere in the forums I am going to go searching. If you guys know what is up with this or where it can be found it would be much appreciated.

Thanks for the help!!!