My prop chip stopped working, then started working again?

turbosupra · 2010-07-20 01:37

short background:

Prop chip is in a vehicle, went out to vehicle today at lunch and chip was functional, ambient temp was around 85F, went out to car 4 hours later, ambient temp was about 95F and chip was not functional. Small LED on usb to serial adapter was still flashing, a full 3.3v was going to prop. Pressed the reset button on the breadboard, still nothing.

Came home and hooked up my laptop and with the serial terminal started to see if I could connect and I immediately saw the serial terminal indicate it had just entered the main pub and then it started working again.

What could cause this? How do I troubleshoot something like this?

Leon · 2010-07-20 01:46

You probably had some heat-sensitive parts that stopped working at 95F. You need to check the spec. for all the relevant components. You could also try using a heat gun on various components, and see if you can identify the one(s) that are failing.

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Leon Heller
Amateur radio callsign: G1HSM

Post Edited (Leon) : 7/20/2010 2:11:07 AM GMT

turbosupra · 2010-07-20 03:24

Hi Leon,

I checked the voltage coming out of the prop and it was 0v when it should have been 3.3, so either the prop failed or the transistor that pin is connected to failed?

I have a laser temperature gauge, so I will use that tomorrow, any idea how hot the prop can get? I wouldn't think that 95F or even 150F is that hot for components?

Leon said...
You probably had some heat-sensitive parts that stopped working at 95F. You need to check the spec. for all the relevant components. You could also try using a heat gun on various components, and see if you can identify the one(s) that are failing.

ElectricAye · 2010-07-20 04:20

turbosupra said...
Hi Leon,

I checked the voltage coming out of the prop and it was 0v when it should have been 3.3, so either the prop failed or the transistor that pin is connected to failed?

I have a laser temperature gauge, so I will use that tomorrow, any idea how hot the prop can get? I wouldn't think that 95F or even 150F is that hot for components?

But did you check the voltage going into the Propeller???

Here is a link to the Propeller's data sheet. I think pages 26 and 27 talk a little about thermal performance.

www.parallax.com/Portals/0/Downloads/docs/prod/prop/PropellerDatasheet-v1.2.pdf

Bear in mind that any electronic component will heat up as it's being used. Normally that heat is lost to the ambient atmosphere and the component stays cool enough to work. But if you've got it in a hot car with the sun beating on it or your gramdmother is sitting on it and it's packaged in such a way that its heat can't flow away from it, then the component can get very hot over time. Power transistors, for example, use heat sinks to help draw the heat away from the transistor, but those heat sinks will be useless if they are trying to move the heat into the center of a solar furnace. Note that a lot of components will show derating data for given circumstances. Is it possible that you were using a power regulator of some sort that has built-in thermal protection, which would cause it to shut down? Or a battery that just couldn't take the heat anymore?

Toby Seckshund · 2010-07-20 08:31

I have noticed that if some critical timing issues (high speed SD card code)·are just on the edge of working then heat will prevent it from working and cold would get it going again.

As you say the internal temperature of cars can get very high, small glasshouse, with black internals.

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Why did I think a new, more challenging, job was a good idea ??

Leon · 2010-07-20 09:58

The Propeller specifications give the ambient temperature range under bias as -55C to +125C, so it should have carried on working at a mere 95C.

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Leon Heller
Amateur radio callsign: G1HSM

turbosupra · 2010-07-20 12:29

Actually I think I was well under the 125C, maybe inside the car got to 150F ?

I'm going to test it again for the next few days. I put my laser temperature probe in the trunk so I can pop the trunk and shoot the chip without opening the car to get as accurate of a reading as possible

Leon said...
The Propeller specifications give the ambient temperature range under bias as -55C to +125C, so it should have carried on working at a mere 95C.

wjsteele · 2010-07-20 12:32

I highly doubt it's the Propeller... I'd check the connections to everything... they'd more than likely be the most suspect when it comes to heat related issues... most components (even cheap Radio Shack junk) will easily handle those temperatures.

I'd also look for a cold solder joint... just a little deformation due to temperature can cause it to break the circuit.

Bill

turbosupra · 2010-07-20 12:34

Hi,

I'm using DC voltage straight from the car battery, which was working good. I tested the voltage regulators and they were receiving 12v and putting out 5v and then 3.3v respectively.

I then checked the pin that was supposed to be putting out 3.3v to turn on a transistor and it was not.

If it happens again I will check the other 1 or 2 output pins to see what they are doing and I will be measuring the surface temperature of each component with my laser temperature gauge.

If that doesn't work, I'm not sure what to do, maybe buy a netbook and see if that catches anything with the serial out? Maybe there is a way to write a log file to an sd card?

ElectricAye said...

turbosupra said...
Hi Leon,

I checked the voltage coming out of the prop and it was 0v when it should have been 3.3, so either the prop failed or the transistor that pin is connected to failed?

I have a laser temperature gauge, so I will use that tomorrow, any idea how hot the prop can get? I wouldn't think that 95F or even 150F is that hot for components?

But did you check the voltage going into the Propeller???

Here is a link to the Propeller's data sheet. I think pages 26 and 27 talk a little about thermal performance.

www.parallax.com/Portals/0/Downloads/docs/prod/prop/PropellerDatasheet-v1.2.pdf

Bear in mind that any electronic component will heat up as it's being used. Normally that heat is lost to the ambient atmosphere and the component stays cool enough to work. But if you've got it in a hot car with the sun beating on it or your gramdmother is sitting on it and it's packaged in such a way that its heat can't flow away from it, then the component can get very hot over time. Power transistors, for example, use heat sinks to help draw the heat away from the transistor, but those heat sinks will be useless if they are trying to move the heat into the center of a solar furnace. Note that a lot of components will show derating data for given circumstances. Is it possible that you were using a power regulator of some sort that has built-in thermal protection, which would cause it to shut down? Or a battery that just couldn't take the heat anymore?

Leon · 2010-07-20 12:46

I think you mentioned that you were using a breadboard, that might be the cause of the problem. They can be very unreliable.

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Leon Heller
Amateur radio callsign: G1HSM

Sapieha · 2010-07-20 13:30

Hi turbosupra.

Some 5V Reg's have very tight HOT circuity and with 12V IN need relative Big Heatsink to function correctly in that Temperatures.

Regards

Ps. One thing to to consider - In car You can have not only 12V but all between 13.V-14V in time You have motor on.
That give 5V reg much extra current to handle - Most of it as HEAT !!

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Nothing is impossible, there are only different degrees of difficulty.
For every stupid question there is at least one intelligent answer.
Don't guess - ask instead.
If you don't ask you won't know.
If your gonna construct something, make it·as simple as·possible yet as versatile as posible.

Sapieha

Post Edited (Sapieha) : 7/20/2010 1:39:39 PM GMT

Leon · 2010-07-20 13:48

I don't think he was running the engine. If he was, that might explain why it stopped working - spikes from the car electrics.

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Leon Heller
Amateur radio callsign: G1HSM

RinksCustoms · 2010-07-20 16:20

breadboards in an automotive environment isn't a good idea (breadboards aren't meant to be used in an environment with vibration) also as you know, if your prop or any of the supporting components were sitting in direct sunlight they were exposed to about 150-160F temperatures, maybe enough to pull things out of spec enough (Vreg's - internally protected against thermal overload, crystal off spec?). When transistors are heated for example, leakage current increases, which increases collector current, which generates more heat, and that process can sometimes lead to thermal runaway. The propeller has been "tested" (read - tortured) by parallax with extreme temperatures (think dry ice and then an oven), the prop kept going when all the support components fell out of spec causing malfunctions, if i recall correctly, parallax eventually had to run wires into the oven from outside just to see where the prop would stop working or what would fail first. So it's possible that your supporting component(s) are having issues with the heat, not the prop. Do you have a heat sink on your 5V regulator? As others noted, for a typical 5V regulator (7805) to drop 7-9.5V it does so in the form of heat emitted, same goes for a 3V version. They are essentially fancy transistors that vary current through them based on the voltage @ the reference pin (GND pin), most have thermal shutdown modes built in. If even adding a heat sink doesn't help stabilize the 5V output, think about getting a fairly cheap DC-DC converter. Are there decoupling caps near the input/output of your 5V regulator to suppress noise spikes? Also, what kind of current are you sourcing/sinking with the prop pin? as i found out, the base of a typical 2n2222 needs about 1mA to work reliably in saturation with 12V Vcc.

As far as troubleshooting goes, you can touch/hold your soldering iron/hot air soldering very close to various components for like 5-7 sec at a time while the setup is powered on and under normal operating voltage cond, this will increase the temperature of the component your testing only, this is good for localizing individual heat related problems (most likely a higher power component first, like your 5V regulator). Measure expected voltages at various points in your circuit, if you find the voltages are off significantly, you probably found your heat related problem. Using a laser temp gun works good for general areas, it's just a passive IR sensor after all.

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Quicker answers in the #propeller chat channel on freenode.net. Don't know squat about IRC? Download Pigin! So easy a caveman could do it...
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Post Edited (RinksCustoms) : 7/20/2010 4:35:47 PM GMT

turbosupra · 2010-07-20 20:29

Hi everyone, thanks for the replies all, I really appreciate the different ideas!

I did some temperature probing today, ambient temp was 88F, car was sitting in direct sunlight. This was at 12 noon. The breadboard and prop assembly, etc is in the back seat, which is not in direct sunlight during 12 noon, but would be as the sun rises and sets.

107F Air inside of car
170F Dashboard (black)
140F Top of steering wheel (black)
120F Leather gear shift knob (black)
125F Propeller chip
140F 5v regulator
107F Floor carpet in the shade

Based on what you all are saying, maybe the following is what happened.

Maybe the voltage regulators overheated. I may have pushed the last code update to the eprom instead of to ram (I can't remember) and so maybe the voltage regulators temporarily failing caused the prop to power down which then caused the eprom to erase? That would be why the reset didn't work? And when I plugged my laptop back in it triggered the chip to reboot or something?

I'm not quite sure how the USB connection could trigger a reboot so to speak, but that USB connection started the chip over again?

I have the parallax only provided regulators, capacitors, etc on the breadboard. The external components such as transistors are from radio shack, and the external resistors/capacitors from various places.

Should I add another stepdown voltage regulator to go from 12-14 down to 9 or something like that?

@RinksCustoms ... 1mA is nothing, I thought it was 4 or 5mA, that's good info to know!

Sapieha · 2010-07-20 20:36

Hi turbosupra.

It is good idea to have 9V Reg.

BUT at last add Heatsink To 5V Reg. As I said in previous post relatively BIG.

Regards.

Ps and if You have possibility one 4004 Diode in series with !2V-14V

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Nothing is impossible, there are only different degrees of difficulty.
For every stupid question there is at least one intelligent answer.
Don't guess - ask instead.
If you don't ask you won't know.
If your gonna construct something, make it·as simple as·possible yet as versatile as posible.

Sapieha

turbosupra · 2010-07-21 10:57

Hi Sapieha,

How big of a heat sink do you recommend, I was hoping to avoid using one because of size.

Also, what will the diode do besides drop voltage a little?

Sapieha said...
Hi turbosupra.

It is good idea to have 9V Reg.

BUT at last add Heatsink To 5V Reg. As I said in previous post relatively BIG.

Regards.

Ps and if You have possibility one 4004 Diode in series with !2V-14V

Sapieha · 2010-07-21 12:36

Hi turbosupra.

Regarding Diode.
That it drop Voltage little is only one extra bonus.
But You must consider at in most vehicle's in time You start engine -- You can have relatively big negative going Inductive Spices from starter electrical motor
and all other inductive Voltages that can be generated in vehicle.
Diode is for cut of all that Voltages.

Regarding Heatsink.
You must experiment on that - else look in spec to REG on heat coefficient curve what it need - in relation to Consumed current.

Regards

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Nothing is impossible, there are only different degrees of difficulty.
For every stupid question there is at least one intelligent answer.
Don't guess - ask instead.
If you don't ask you won't know.
If your gonna construct something, make it·as simple as·possible yet as versatile as posible.

Sapieha

turbosupra · 2010-07-22 02:26

Ok,

My chip did this again I get a check engine light as soon as the chip or whatever component stops working, at 6pm I went to the movies after driving around for 45 minutes with the a/c on, in car temp was about 75F. I parked the car, got out and didn't like my parking location so I got back in and started the car and the check engine light came on immediately. Meaning that the prop failed or went into an endless loop in the code or?

Inside the car was about 75F, I had my laser temp gun and shot all of the components and the warmest was 125F, the prop was 110F. I then removed and plugged in each output and input that I had and it did not effect the prop. The prop was not outputting on any of the 3 pins I'm using for it. I then wiggled the board, and every component on it and it changed nothing. Then I verified all voltages and grounds on the board and they were all correct including right at the prop pin. After that I tried a reset of the prop with the reset button, no response on the usb to serial connector LEDs or the prop output pins. Next I tried removing power from the prop and then ground, that did not bring it back. I went to the movie and got home 3 hours later, performed the same tests, still no change. After that I recorded the values on video if anyone wants to see what I did, the link is below and then I recorded when I plugged in the usb cable how it jump started the prop and once again it was working immediately and stayed working after I unplugged it.

What could cause this, I'm completely confused? I tried to rule out everything but the prop and the code I have running on it.

To see where I plug in the usb cable to the laptop jump to 3:35, at 4:00 is where the chip enters it's main pub, so either the code is timing out and the usb connection is restarting it or it is freezing and the usb connection is restarting it or something??


PUB Main


  Debug.Start(31,30,0,115200) 'start cog with serial driver
  Debug.Str(string("Debug-output started",13))
  Debug.Str(string("******* Entering Main Pub *******",13))
  waitcnt(clkfreq + cnt)
  dira[noparse][[/noparse]c_EngineRunningPin]      := 0
  ina[noparse][[/noparse]c_IgnitionOnPin]          := 1

  Debug.Str(string("Right before repeat loop",13))

  PressureSensorOutput := 0

  Cognew(PWMout , @PWMoutStack)
  Debug.Str(string("Cognew(PWMout, @PWMoutStack)  done",13))
  Debug.Str(string("IO-Pin starts to switch on/off ",13))

  oscillationtime := 500

  Cognew(Measure_rpm,@rpm_Stack)

  Cognew(TrunkTrigger_PulseChecking, @Trunktriggerstack)

  Cognew(Lift, @Liftstack)

  'Cognew(Lift_Feedback_Control, @Lift_Feedbackstack)
  
  
  
      repeat  ' repeat loop starts here

RinksCustoms said...
breadboards in an automotive environment isn't a good idea (breadboards aren't meant to be used in an environment with vibration) also as you know, if your prop or any of the supporting components were sitting in direct sunlight they were exposed to about 150-160F temperatures, maybe enough to pull things out of spec enough (Vreg's - internally protected against thermal overload, crystal off spec?). When transistors are heated for example, leakage current increases, which increases collector current, which generates more heat, and that process can sometimes lead to thermal runaway. The propeller has been "tested" (read - tortured) by parallax with extreme temperatures (think dry ice and then an oven), the prop kept going when all the support components fell out of spec causing malfunctions, if i recall correctly, parallax eventually had to run wires into the oven from outside just to see where the prop would stop working or what would fail first. So it's possible that your supporting component(s) are having issues with the heat, not the prop. Do you have a heat sink on your 5V regulator? As others noted, for a typical 5V regulator (7805) to drop 7-9.5V it does so in the form of heat emitted, same goes for a 3V version. They are essentially fancy transistors that vary current through them based on the voltage @ the reference pin (GND pin), most have thermal shutdown modes built in. If even adding a heat sink doesn't help stabilize the 5V output, think about getting a fairly cheap DC-DC converter. Are there decoupling caps near the input/output of your 5V regulator to suppress noise spikes? Also, what kind of current are you sourcing/sinking with the prop pin? as i found out, the base of a typical 2n2222 needs about 1mA to work reliably in saturation with 12V Vcc.

As far as troubleshooting goes, you can touch/hold your soldering iron/hot air soldering very close to various components for like 5-7 sec at a time while the setup is powered on and under normal operating voltage cond, this will increase the temperature of the component your testing only, this is good for localizing individual heat related problems (most likely a higher power component first, like your 5V regulator). Measure expected voltages at various points in your circuit, if you find the voltages are off significantly, you probably found your heat related problem. Using a laser temp gun works good for general areas, it's just a passive IR sensor after all.

turbosupra · 2010-07-22 13:27

My code should loop for just about eternity, correct?

wjsteele · 2010-07-22 14:12

Well, that depends... that first cog looks like it will, but without seeing the other cogs code, we don't know what they do.

Bill

turbosupra · 2010-07-22 18:06

All of the other cogs are called within pub main

I'm trying to figure out what could have stopped that method from running?

wjsteele said...
Well, that depends... that first cog looks like it will, but without seeing the other cogs code, we don't know what they do.

Bill

turbosupra · 2010-07-22 21:43

I hope that someone finds this during a search if they ever encounter it as I've found my culprit which is pictured below (thanks David@Parallax)

I unplugged the serial to usb converter from the 4-pin right-angle header, SIP 0.1" (see pics below) and the prop was up and functioning as normal within 2 seconds, cycling through the cogs and outputting to my output hardware.

soshimo · 2010-07-23 03:27

turbosupra said...
I hope that someone finds this during a search if they ever encounter it as I've found my culprit which is pictured below (thanks David@Parallax)

I unplugged the serial to usb converter from the 4-pin right-angle header, SIP 0.1" (see pics below) and the prop was up and functioning as normal within 2 seconds, cycling through the cogs and outputting to my output hardware.

I'm glad you found your issue, but that doesn't really help anyone searching these forums. I use propplug and an FTDI usb->serial converter. I've never experienced the issues you are describing. I had an FTDI board go out on me (one of the SparkFun ones, no less). It just stopped reading serial data - it didn't make the program randomly stop working.

What, in particular, was the cause? Do you have a bad FTDI board? Is there a short somewhere? That would be the most helpful information tbh.

LeeMark · 2010-07-23 06:00

Hi Mate

I think 95F temperature might have caused the problem. I suggest you to check the components and their maximu temperature range.

lanyard[noparse][[/noparse]/url

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lanyard

Leon · 2010-07-23 09:52

95F shouldn't cause a problem. 95C might.

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Leon Heller
Amateur radio callsign: G1HSM

turbosupra · 2010-07-24 02:10

How does that not help anyone searching?

Parallax told me that the chip tries to push serial out to the computer and it cannot and that this causes the chip to reset? Then eventually it locks up, they described this as a 'known issue' based on the way he spoke about it.

I don't believe it is bad, it still works it just causes issues when the data cannot write to the serial console window? If you want specifics, call David@Parallax as he would be the expert.

soshimo said...

I'm glad you found your issue, but that doesn't really help anyone searching these forums. I use propplug and an FTDI usb->serial converter. I've never experienced the issues you are describing. I had an FTDI board go out on me (one of the SparkFun ones, no less). It just stopped reading serial data - it didn't make the program randomly stop working.

What, in particular, was the cause? Do you have a bad FTDI board? Is there a short somewhere? That would be the most helpful information tbh.

Duane Degn · 2010-07-24 03:20

turbosupra,

I take you had the PropPlug connected the whole time?· This seems like the problem many have had with the Propeller Demo Board and Prop Proto Board with USB.· If there is a·tx signal to the FTDI chip, it resets·the·Prop.· I was having this problem when·I found someone else on the forum having similar trouble which was quickly cleared up·thanks to·one of the many·helpful·people here.· I now cut the·reset trace on my USB Proto Boards and use a jumper (to reconnect the reset line) when I'm programming it.· I'm pretty sure there are several more elegant solutions to this problem.

Duane

turbosupra · 2010-07-24 11:21

Duane,

That definitely sounds like it. Any pics of how you do that, just for the thread reference?

Duane Degn said...
turbosupra,

I take you had the PropPlug connected the whole time? This seems like the problem many have had with the Propeller Demo Board and Prop Proto Board with USB. If there is a tx signal to the FTDI chip, it resets the Prop. I was having this problem when I found someone else on the forum having similar trouble which was quickly cleared up thanks to one of the many helpful people here. I now cut the reset trace on my USB Proto Boards and use a jumper (to reconnect the reset line) when I'm programming it. I'm pretty sure there are several more elegant solutions to this problem.

Duane

My prop chip stopped working, then started working again?

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