Post by thread:Automotive / PIC

I am interested in using PICs for automotive gadgets. Are there any sites that anyone knows about that might be helpful. In particular, what if any, special precautions must be followed to ensure reliable operation in the vehicle environment. I suspect some kind of power conditioning and spike suppression etc. would be needed. Thanks in advance.

At 06:26 AM 5/13/97 -0500, you wrote: >I am interested in using PICs for automotive gadgets. Are there any >sites that anyone knows about that might be helpful. In particular, what >if any, special precautions must be followed to ensure reliable operation >in the vehicle environment. I suspect some kind of power conditioning >and spike suppression etc. would be needed. Thanks in advance. > You're right about about power conditioning. I am a design engineer for an automotive OEM, and the auto companys have stringent requirements that electronic products must withstand. You have to consider the following (electrical) items: Normal Operating voltage range of 9 to 16 v Reverse voltage withstanding capability 24 V supply withstanding capability. This is due to 24V "hot shot" battery boost Load dump/transient withstanding: Varies, but figure you got to withstand 100 volt pulse which is on the order of 50 microsec in duration. Don't forget the enviromental conditions, esp. if you are under the hood. M Walter

<<< From: Danny Chicotel <spam_OUTDRChicotelTakeThisOuTMARATHONOIL.COM> I am interested in using PICs for automotive gadgets. Are there any sites that anyone knows about that might be helpful. In particular, what if any, special precautions must be followed to ensure reliable operation in the vehicle environment. I suspect some kind of power conditioning and spike suppression etc. would be needed. Thanks in advance. >>> Hi, It would depend on your intended 'market'. If it is a 'gadget' for yourself or a friend then you need take no special precautions. I have built a PIC'84 based thing that lived in the driver's compartment, and had a sensor by a wheel, wired through the engine bay. It was in a plastic box, but I would recommend a metal box as you will probably use a voltage regulator from 12v to 5v and will want to wick away all that heat. Also for one-off quantities you can choose a regulator that has short-circuit and reverse-polarity protection. You should shield all your sensor leads, and maybe zener clamp any inputs, but again if it is a hobbyist device why bother. You are sure to learn something if it goes bang, but PICs seem to be mostly bomb-proof anyway. I have been away from the PICLIST for about a year now, although I have been lurking. It is nice to see familiar names still there. BTW if anyone's interested I have details on how to make money fast, and it really works...! Andy (the other one) --- (made up sig tacked on the end as we have cc:Mail, an appalling example of an email system) Software Engineer Synaptics Inc.