MpGuino keeps resetting.

[bbjsw10]

I have tryed everything I can think of to solve my issue on this.

It will reset randomly when eoc-ing and shutting off car when parking. I have checked voltage. 4.98v on the output of 7805. Checked all connections solder joints good, car connections are soldered as well.

I have installed a second 12v 2ah battery under dash, which is connected to vehicle with current limiting resistor(600 mah) and a diode. The resistor is so I don't fry the 2ah battery by charging too fast, it also limits voltage to 11.5v going to the guino's 7805.

The last time it reset I had about 140 miles on tank, was going to put some gas in tommorow to get a rough setting on gallon usage. But the guino decided to reset so I have to start all over again.

I have also added a 470uf in parallel with the 330uf cap on output of 7805. I don't know what else to do.

I have noticed the lockup issue I was having has not happened since adding the extra cap and backup battery. And this issue was happening more when hotter out, the guino is out of case right now for diagnosis and nothing has even felt slightly warm to touch.

I am lost please help. Ran out of ideas, other than maybe backlight on lcd maybe?

[dcb]

You and ptsmith24 should compare notes cuz he is having some issues too, the thing runs for weeks on end in my cars so there is something different about your environment.

you have an iduino based version? using .73/.74? Any code tweaks?

Is there any pattern to when it resets?

like after a certain amount of time or distance or fuel usage or right when you start the engine or use the horn or kill switch or ???

[wagonman76]

Does yours use a power supply jack, or is it hardwired to the board? Ive seen plenty of power supply jacks and plugs that break internally. But the way it acts up when you shut the engine off seems pretty consistent, besides you have basically a UPS for it now, so I dont think its a main power issue.

Hows your ground? Is it connected right to the car frame, or another ground wire that might be getting fishy signals when you kill the engine?

I also wonder if it might be getting a spike through one of the data input lines. Maybe try higher value resistors in the data lines?

[bbjsw10]

Originally Posted by dcb

You and ptsmith24 should compare notes cuz he is having some issues too, the thing runs for weeks on end in my cars so there is something different about your environment.

you have an iduino based version? using .73/.74? Any code tweaks?

Is there any pattern to when it resets?

like after a certain amount of time or distance or fuel usage or right when you start the engine or use the horn or kill switch or ???

Iduino - Yes
Version .73 no tweaks
No pattern random (main problem with tracking down too can't duplicate at certain intervals)
Just when either shutting off with coil kill or ignition. No other items causing it.

Originally Posted by wagonman76

Does yours use a power supply jack, or is it hardwired to the board? Ive seen plenty of power supply jacks and plugs that break internally. But the way it acts up when you shut the engine off seems pretty consistent, besides you have basically a UPS for it now, so I dont think its a main power issue.

Hows your ground? Is it connected right to the car frame, or another ground wire that might be getting fishy signals when you kill the engine?

I also wonder if it might be getting a spike through one of the data input lines. Maybe try higher value resistors in the data lines?

Uses a connector but a good one, no way could be loose connection there. I believe also not a power issue anymore as well.

Actually I have not checked ground, I may look into this tomorrow.

I was wondering same thing on spikes on inputs. How much larger of a resistor should I use in there and still receive signal?

[wyatt]

I was having a very similar problem. Mine would lock up, the LCD screen would go blank, come back... for no apparent reason. I just started going case-less this past week, and whenever it acts up, I pull off the road and start poking around. I found that the resonator on my iDuino board is lose, so I will be re-touching that with a soldering iron. I stuffed some napkin between it and the chip, and it has worked flawlessly for 3 days straight, (when I would normally get about 1/2 day before). It was not possible to find without poking around at different components when the problem was present, since I had tested all the connections several times and nothing indicated a problem because I was making a connection with the force of my multimeter probes.

[cmags]

I'm having a lockup issue too. It's definitely not consistent. Last night it seems like it may have occurred after parking, but it wasn't on shutdown of the engine, because I EOC'ed a qtr mile to my parking spot. The whole thing was hung, couldn't change brightness - the LCD was still illuminated this morning (stayed lit all night).

I have been having some odd issues on the VSS signal, where for a while it was reading the speed just fine, then it seems like it just stopped recognizing the signal right. It was OK one minute (highway driving), then the speed on the 'guino started dropping and for a while showed ~15mph. During this time, even when stopped it showed ~5mph, and seemed variable based on engine RPM speed (in neutral, parked). Then it just dropped out to 0.

Reflashed from .067 to .074. Seemed to resolve the VSS issue (at least for now), but not the hang.

Hardware modifications:
Added 50k resistor at INJ tap (so we have INJ --- 50k --------- 100k/zener --- 'guino)

Software modifications:
Swapped RS and EN (pins 4 & 5) in SW for a wire cross mistake in HW (oops).
Customized "Custom" screen.
Modded Setup screen to position cursor at XX rather than first digit (p=11).

[ptsmith24]

Mine locked up a couple of times. But, since mounting it in front of an air vent (with outside air selected), it hasn't frozen. I'm not ready to say that's the solution that worked for me, but the evidence is there so far. I had it mounted on a piece of trim just in front of the plastic cover on my gauge faces. However, during the lockups, I noticed a good bit of heat in that area compared to just outside of the steering wheel area. Hope that helps. It isn't in a case. Because of the lock ups, I have not been able to get a tankful of numbers for calibration, just yet. However, I'll be driving close to 1k miles this weekend, so it should be good to go within a week.

[Magister]

It took me month to find that on my test unit, the problem comes from bad default values of the brownout detection...

At 16MHz the chip need voltage, and when it drops below a certain point, the ATMEGA can execute random instructions or flip bit in memory.

By default the brownout voltage is set to 2.7V which is way too low. The only solution is to adjust the value to 4.3V (change high_fuses to 0xDC) and re-burn the bootloader. I did it with the "parallel programmer".

Now I have never had a reset or bad flash again. Maybe this is part of the problem of some people in this thread.

See Arduino Forum - Request: bootloader options for brownout detection for explanation.

Believe me, this had driven me crazy for months!

[cmags]

Interesting. This does make sense, because I never experienced a lockup/reset before hardwiring my 'guino. Prior to that I was running off the 5v from my carPC which was far more consistent than battery power it seems. (But then again, my 5v stand by would only stay on for 2 hrs after shutting off the car, so I may not have been running long enough between resets to see the issue.)

Is there a way to burn a new bootloader with either the iDuino's USB interface or the Freeduino v1.0's serial interface?

[bbjsw10]

Originally Posted by Magister

By default the brownout voltage is set to 2.7V which is way too low. The only solution is to adjust the value to 4.3V (change high_fuses to 0xDC) and re-burn the bootloader. I did it with the "parallel programmer".

Now I have never had a reset or bad flash again. Maybe this is part of the problem of some people in this thread.

Changing this brownout voltage, means what? That it will retain memory upon a brownout?

How do you make this parallel programmer, I have cords and extra sockets for the 128.