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something wicked this way comes caution for dialup get a snack


oddcomp
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I have some assembly code that I wrote floating around somewhere for controlling RC servos. There must be tons of code to do that on the web, it's pretty easy to write. IIRC a pulse at 40-100Hz from 1ms to 2ms with the middle of the travel at 1.5ms.

 

I haven't played around with BASIC for any microcontrollers, but in general BASIC programs are big and slow. If it works for this application that would be great because it's easy to write. Virtually all of the code I have written for microcontrollers has been in assembly or C.

 

If I were designing something like this I would definately want good power supply regulation/filtering, power supply monitoring, a watchdog timer, and some sort of serial debug/admin/program interface. Chosing a uC with in-circuit serial programming and EEPROM data memory would be wise. Don't forget about some ESD protection on the I/O's. The automotive environment is very harsh. Potting or conformal coating the finished circuit might be a good idea.

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cool i'll take what ever bits and pieces you can spare i got other things that will need servo op also like a lcd display slider thingy

 

 

btw after lots of pondering and rediscovering those things called hood pins i am gonna attempt to wedge the fmic and radiator that i have here from a saab 9000 into the wagon.. hehe

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...Don't forget about some ESD protection on the I/O's. The automotive environment is very harsh. Potting or conformal coating the finished circuit might be a good idea.

There are some pretty good buffer ICs out there. And the stock ECU uses neither conformal nor potting and they survive pretty well. I wouldn't get too worked up over it.

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The body modules I worked on for Motorola were conformal coated, and many of the underhood ECU's out there are potted. It really depends where one wants to put it and how well the enclosure will be sealed. Potting is easy for a DIY'er to do and it offers improved vibration resistance and resistance to moisture and contaminants. If you put it in the cabin then no worries, under the hood and I would pot it. The servo should definately be a waterproof one.

 

I work on mission critical equipment that is deployed to the far corners of the planet, so I tend to belt and suspenders everything. Sorry if my suggestions border on excessive. ;) I suppose if this circuit failed no one's life would be in danger.

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  • 3 months later...

just a tiny useless update

 

sadly i pulled the motor from the wagon..too mujch time + money to acually put it back' on the road ..

 

the good news is that my work will continue butnot in wagon form

this morning i pulled a dead ea82t motor from my "new" used suby

and dropped the megasquirted+edis'd xt intake'd hks ssqv b.o.v'd ford thunderchicken intercooled chevy alternated ea82t from my wagon into a nice

85 r/x 4 door 5speed dual range with lsd

 

i hope to rewire it in the next few days and do the intercooler pipes

i have taken a few pics old motor / old wagon motor install

and since i have a digital video camera i lan on making a few short clips of the whole setup .. in action like on the highway

some dirt maybe a few failed 4wd drifts somewhere

some vids of the screen on my laptop showing what the motor is doing "thanks ed i dug up a battey pack for it now woot!!"

 

with any luck i plan on heading up to portland internatonal raceway

to get a time slip before wcss7... at leasti hope i can

i iwsh i had the 80-100 bux it requires to get about 3 runs on a dyno so i could get a better tune on the motor but eh oh well

i will be just happy to have a <slightly altered> subaru again on the road

 

oof its nap time :)

 

still gotta figure out how to move a large cooler with a rx hmmm

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