Post by thread:[OT]: Other Microcontrollers

I'm interested in knowing what microcontrollers group members use when they are not using PICs -- specifically in low-power or high-temperature (>=150C) applications. I've used the MSP430 for low-power applications up to 125C and the PIC 16F877 for higher-temperature circuits. And in reference to high-temperature design, what part of the design fails first at the temperature rises -- I have observed the oscillator and external serial flash to be the first to go. Thanks. -Shawn _________________________________________________________________ MSN Photos is the easiest way to share and print your photos: http://photos.msn.com/support/worldwide.aspx -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

At 09:21 AM 7/21/02 -0700, you wrote: >Just curious, what kind of applications are you developing ? > >Oil drilling probes ? Honeywell has some 8051s that are spec'd to operate over 200'C. Especially for down-hole telemetry stuff. A bit pricey ($1K or so, IIRC), and the specs suffer. I try to keep the temperature low by any means available, but in a hole in the ground it is not possible. Other micros? 8051s, 68HC05/8 and MSP430F. Over 125'C you are getting into specialist territory. It might even make sense to qualify them yourself if the app is non-critical. >Or just parking meters for Arizona. ;-) Haha. ;-) The ones in Toronto have a solar panel and cellular phone antenna on them (there are only a couple per block and you print out a ticket* to place on the dash). They take credit and debit cards, and so far, seem very reliable compared to the electronic individual meters. I guess they "phone home" when they are full of money, as well as to validate credit cards and call for help if they are being attacked(?). * The tickets have advertising (eg. city-wide pizza places) printed on the back, so I suspect they actually make money on the paper they use. Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" spam_OUTspeffTakeThisOuTinterlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com 9/11 United we Stand -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

I wonder how they'll ever remake cool hand luke if these go up everywhere? -Adam Spehro Pefhany wrote: {Quote hidden}> > Haha. ;-) The ones in Toronto have a solar panel and cellular phone > antenna on them (there are only a couple per block and you print out > a ticket* to place on the dash). They take credit and debit cards, and > so far, seem very reliable compared to the electronic individual meters. > I guess they "phone home" when they are full of money, as well as to > validate credit cards and call for help if they are being attacked(?). > > * The tickets have advertising (eg. city-wide pizza places) printed on > the back, so I suspect they actually make money on the paper they use. > > Best regards, > > Spehro Pefhany --"it's the network..." "The Journey is the > reward" > .....speffKILLspam@spam@interlog.com Info for manufacturers: > http://www.trexon.com > Embedded software/hardware/analog Info for designers: > http://www.speff.com > 9/11 United we Stand > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > > > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Tal wrote: >Just curious, what kind of applications are you developing ? > >Oil drilling probes ? > >Or just parking meters for Arizona. ;-) > You're right, most of our work involves down-hole drilling applications. I know that Honeywell/Motorola offer high-temp microcontrollers, but they are extremely pricey. I have done lots of heat testing with TI and Microchip parts and I was interested in hearing if anyone else had done testing with low-cost MPUs. I've also done some playing with Atmel flash and it's gone to about 125-130C. -Shawn P.S.: It's pretty hot in Calgary this summer, but not quite Arizona. _________________________________________________________________ Chat with friends online, try MSN Messenger: http://messenger.msn.com -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

The automotive industry must use high heat chips. Bill ----- Original Message ----- From: "Shawn Mulligan" <mulliganshawnKILLspamHOTMAIL.COM> To: <.....PICLISTKILLspam.....MITVMA.MIT.EDU> Sent: Sunday, July 21, 2002 3:43 PM Subject: Re: [OT]: Other Microcontrollers > Tal wrote: > > >Just curious, what kind of applications are you developing ? > > > >Oil drilling probes ? > > > >Or just parking meters for Arizona. ;-) > > > You're right, most of our work involves down-hole drilling applications. I > know that Honeywell/Motorola offer high-temp microcontrollers, but they are > extremely pricey. I have done lots of heat testing with TI and Microchip > parts and I was interested in hearing if anyone else had done testing with > low-cost MPUs. I've also done some playing with Atmel flash and it's gone to > about 125-130C. > > -Shawn > > P.S.: It's pretty hot in Calgary this summer, but not quite Arizona. > > __________________________________________________ _______________ > Chat with friends online, try MSN Messenger: http://messenger.msn.com > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

At 07:37 PM 7/21/02 -0700, you wrote: >The automotive industry must use high heat chips. Typically spec'd over the -40 to 125'C temperature range. Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" EraseMEspeffspam_OUTTakeThisOuTinterlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com 9/11 United we Stand -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

" The automotive industry must use high heat chips." Bill, the CPU module in my '86 Chevrolet Caprice enjoyed a nice comfortable ride inside the passenger compartment! It was behind the right side kick panel ... I popped it open - don't remember now what the CPU chip was but the "big boy" on board was in a 40 pin package (ceramic or plastic I can't recall). RF Jim ----- Original Message ----- From: "Bill & Pookie" <williamcornutt111spam_OUTATTBI.COM> To: <@spam@PICLISTKILLspamMITVMA.MIT.EDU> Sent: Sunday, July 21, 2002 9:37 PM Subject: Re: [OT]: Other Microcontrollers > The automotive industry must use high heat chips. > > Bill > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Could you use active cooling and a insolated box to protect the chips ??? ----- Original Message ----- From: "Spehro Pefhany" <KILLspamspeffKILLspamINTERLOG.COM> To: <RemoveMEPICLISTTakeThisOuTMITVMA.MIT.EDU> Sent: Sunday, July 21, 2002 11:09 PM Subject: Re: [OT]: Other Microcontrollers > At 07:37 PM 7/21/02 -0700, you wrote: > >The automotive industry must use high heat chips. > > Typically spec'd over the -40 to 125'C temperature range. > > Best regards, > > Spehro Pefhany --"it's the network..." "The Journey is the reward" > spamBeGonespeffspamBeGoneinterlog.com Info for manufacturers: http://www.trexon.com > Embedded software/hardware/analog Info for designers: http://www.speff.com > 9/11 United we Stand > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Modern active cooling is a simple heat pump - take heat from A, move it to B. I imagine that taking the heat from the hole and moving to the top of the hole, while possible, is likely not practical, and sending the stuff down in an ice pack (or liquid N) probably increases the weight for only a little benefit (ie, it's going to be in the hole long enough to boil off several gallons of liquid N if you want to gather any meaningful data) There is a right way, and an ugly kludge. It's very likely that the right way is sending down equipment that can handle the stresses placed on it, rather than making the environment fit the equipment (at which point you probably lose much of the value of the data gathered down there anyway) -Adam Archmage wrote: >Could you use active cooling and a insolated box to protect the chips ??? > > >{Original Message removed}

"M. Adam Davis" <TakeThisOuTadampicEraseMEspam_OUTUBASICS.COM> wrote: > Modern active cooling is a simple heat pump - take heat from A, move it > to B. > > I imagine that taking the heat from the hole and moving to the top of > the hole, while possible, is likely not practical, ... Why not? All you need is a Peltier Junction array (or a stack of them) that is capable of keeping a tiny insulated box containing the active chips below their maximum rated temperature, while outputting the heat into the drilling slurry stream at something higher than *its* temperature. No moving parts; should work indefinitely as long as there's sufficient electricity to run it. > There is a right way, and an ugly kludge. It's very likely that the > right way is sending down equipment that can handle the stresses placed > on it, rather than making the environment fit the equipment (at which > point you probably lose much of the value of the data gathered down > there anyway) Good attitude, but you need to take a top-down view. If you can create an enclosure that can withstand the enviroment while providing a more component-friendly environment inside, then you don't need to qualify every chip, wire and solder joint inside the box for the harsher environment. -- Dave Tweed -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

I can see that. The components wouldn't generate much heat (if designed carefully they would emit very little heat). Put them inside an insulated container with a stack of peltiers... Then you'd only have to find out the differential each peltier could handle, it's current consumption at that differential, and the total difference between the two temperatures. Getting the heat transferred off the last peltier would be the trick - is a heat sink going to manage it, or is it going to get fouled? -Adam Dave Tweed wrote: {Quote hidden}>"M. Adam Davis" <RemoveMEadampicTakeThisOuTUBASICS.COM> wrote: > > >>Modern active cooling is a simple heat pump - take heat from A, move it >>to B. >> >>I imagine that taking the heat from the hole and moving to the top of >>the hole, while possible, is likely not practical, ... >> >> > >Why not? All you need is a Peltier Junction array (or a stack of them) >that is capable of keeping a tiny insulated box containing the active >chips below their maximum rated temperature, while outputting the heat >into the drilling slurry stream at something higher than *its* >temperature. No moving parts; should work indefinitely as long as >there's sufficient electricity to run it. > > > >>There is a right way, and an ugly kludge. It's very likely that the >>right way is sending down equipment that can handle the stresses placed >>on it, rather than making the environment fit the equipment (at which >>point you probably lose much of the value of the data gathered down >>there anyway) >> >> > >Good attitude, but you need to take a top-down view. If you can create >an enclosure that can withstand the enviroment while providing a more >component-friendly environment inside, then you don't need to qualify >every chip, wire and solder joint inside the box for the harsher >environment. > >-- Dave Tweed > >-- >http://www.piclist.com hint: The list server can filter out subtopics >(like ads or off topics) for you. See http://www.piclist.com/#topics > > > > > > > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> " The automotive industry must use high heat chips." > > Bill, the CPU module in my '86 Chevrolet Caprice enjoyed > a nice comfortable ride inside the passenger compartment! > > It was behind the right side kick panel ... > > I popped it open - don't remember now what the CPU chip was > but the "big boy" on board was in a 40 pin package (ceramic > or plastic I can't recall). In most GMs (don't know other companies) the ECM (or "computer") is located exactly where you describe, on the firewall just above the passengers feet. It is usually based on a Motorolla MCU, 6800 series IIRC. Later models use Intel, I think. TTYL -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Remember that peltiers are not very efficient and will generate a lot of heat themselves. This is why when you stack them you need progressively more elements per layer. Also for hi-temp apps, remember that standard peltiers use low melting-point solders in their construction, which will limit their operating range. Wouldn't surprise me if they wouldn't stand much more temp than most ICs. On Mon, 22 Jul 2002 10:41:43 -0400, you wrote: {Quote hidden}>I can see that. The components wouldn't generate much heat (if designed >carefully they would emit very little heat). > >Put them inside an insulated container with a stack of peltiers... > >Then you'd only have to find out the differential each peltier could >handle, it's current consumption at that differential, and the total >difference between the two temperatures. > >Getting the heat transferred off the last peltier would be the trick - >is a heat sink going to manage it, or is it going to get fouled? > >-Adam > >Dave Tweed wrote: > >>"M. Adam Davis" <adampicEraseME.....UBASICS.COM> wrote: >> >> >>>Modern active cooling is a simple heat pump - take heat from A, move it >>>to B. >>> >>>I imagine that taking the heat from the hole and moving to the top of >>>the hole, while possible, is likely not practical, ... >>> >>> >> >>Why not? All you need is a Peltier Junction array (or a stack of them) >>that is capable of keeping a tiny insulated box containing the active >>chips below their maximum rated temperature, while outputting the heat >>into the drilling slurry stream at something higher than *its* >>temperature. No moving parts; should work indefinitely as long as >>there's sufficient electricity to run it. >> >> >> >>>There is a right way, and an ugly kludge. It's very likely that the >>>right way is sending down equipment that can handle the stresses placed >>>on it, rather than making the environment fit the equipment (at which >>>point you probably lose much of the value of the data gathered down >>>there anyway) >>> >>> >> >>Good attitude, but you need to take a top-down view. If you can create >>an enclosure that can withstand the enviroment while providing a more >>component-friendly environment inside, then you don't need to qualify >>every chip, wire and solder joint inside the box for the harsher >>environment. >> >>-- Dave Tweed >> >>-- >>http://www.piclist.com hint: The list server can filter out subtopics >>(like ads or off topics) for you. See http://www.piclist.com/#topics >> >> >> >> >> >> >> -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Since flash is not so heat resistant why not use OTP or better CERDIP EPROM based PICs with no onboard A/D or other analog devices and with external clock from a heat-rated can oscillator (or diy). Once upon a time I made some tests and I came to the conclusion that one can make parts work a little beyond the rated temperature by tampering with the supply voltage. The main effects of temperature are to shift the leakage and thresholds (increases with CMOS) and decrease the gain. Thus higher voltage and shifted IO logic levels should work for CMOS, with a derated (?) clock. My experiments were with NMOS parts where things behave differently. I suspect that a CERDIP 16C54A/XT (I still have those) could be run at 150deg C with 500kHz clock at 5.5V or so. The chips may have to be reprogrammed every half a year or so since the EPROM is also erased faster when hot. Peter -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

I appreciate your advice. The flash in this instance is used for external data logging so OTP wouldn't be helpful. The heat-rated can oscillator approach is something I will experiment with, as well as varying supply voltage and clock frequency. Firstly, I will experiment with voltage levels, going from 3.3V parts to 5.0V. Thank you again. Further, some people have suggested elaborate cooling stategies; however, unfortunately in the down-hole drilling business everything is powered by lithium batteries and power consumption is a real limiting concern. -Shawn {Original Message removed}

You really are limited in many ways. You have to accept the stresses of the environment -- pressure, temperature, vibration, space limitations, power sources, etc. -Shawn {Quote hidden}> There is a right way, and an ugly kludge. It's very likely that the > right way is sending down equipment that can handle the stresses placed > on it, rather than making the environment fit the equipment (at which > point you probably lose much of the value of the data gathered down > there anyway) > > -Adam > > Archmage wrote: > > >Could you use active cooling and a insolated box to protect the chips ??? > > > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

On Mon, 22 Jul 2002, shawnmulligan wrote: >I appreciate your advice. The flash in this instance is used for external >data logging so OTP wouldn't be helpful. The heat-rated can oscillator >approach is something I will experiment with, as well as varying supply >voltage and clock frequency. Firstly, I will experiment with voltage levels, >going from 3.3V parts to 5.0V. Thank you again. I think that those fram parts (ferro-electric ram) are rated for high temperature. If I understand well the fram cell will stay the way it was programmed until the Curie temperature is reached. This may be high enough for you to try it out even if it is out of spec. Peter -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> -----Original Message----- > From: M. Adam Davis [SMTP:EraseMEadampicUBASICS.COM] > Sent: Monday, July 22, 2002 3:42 PM > To: RemoveMEPICLISTEraseMEEraseMEMITVMA.MIT.EDU > Subject: Re: [OT]: Other Microcontrollers > > I can see that. The components wouldn't generate much heat (if designed > carefully they would emit very little heat). > > Think about what would control the TEC's. They need amps of current to pump heat if working near their maximum delta T. A linear system will give off considerable heat, a switching system is likely to give noise problems. It's possible you could get away without any form of temperature control, just apply enough voltage accross the TEC's for the worst case, but you would have to be very carefull that the cold sides didn't get cold enough to damage the circuit when the unit is operating at temperatures condierably lower than it's maximum. TEC's are interesting and occaisionaly usefull engineering solutions, but their disadvantages can often outweigh any benefits. Regards Mike -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> -----Original Message----- > From: M. Adam Davis [SMTP:RemoveMEadampicspam_OUTKILLspamUBASICS.COM] > Sent: Monday, July 22, 2002 3:42 PM > To: RemoveMEPICLISTTakeThisOuTspamMITVMA.MIT.EDU > Subject: Re: [OT]: Other Microcontrollers > > I can see that. The components wouldn't generate much heat (if designed > carefully they would emit very little heat). > > Think about what would control the TEC's. They need amps of current to pump heat if working near their maximum delta T. A linear system will give off considerable heat, a switching system is likely to give noise problems. It's possible you could get away without any form of temperature control, just apply enough voltage accross the TEC's for the worst case, but you would have to be very carefull that the cold sides didn't get cold enough to damage the circuit when the unit is operating at temperatures condierably lower than it's maximum. TEC's are interesting and occaisionaly usefull engineering solutions, but their disadvantages can often outweigh any benefits. Regards Mike -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.