AVR Freaks

Great guys, thanks.

The silicone compound has almost hardened and now the built-in sensor on a 80cm coax (100pF) refuses to work. A fresh DS1820 in the breadboard works fine. Is that 100pF of the coax the killing factor ?? It reads 85 degr C all the time.

< some more testing .... >

O crap, the fresh DS1820 in the breadboard works fine, even with 220pF in parallel. Apparently I damaged the glued-in one when soldering it to the coax. Not a good day. :(

George, I am aware that the DS1820 is an obsolete part: but I had 4 in stock, and accuracy is not that important for this purpose. My bike (Honda Shadow VT500C) is a fluid-cooled engine, with a fan behind the radiator that kicks in @ 80 degr C. So I am lucky.
Automotive is a hostile environment, I know. Worked in automotive for several years.

Attached a picture of the poor bugger. And those ugly looking black creatures are the new pulse generators. Completely covered in 250 degr resistant silicone mastique. I need my own extruder for plastics ! :)

DS1820 out, good old NTC in.

cheers

Nard

Not a few centigrades, George. We had a very cold weather a few weeks ago (minus 15, all is relative, of course) and I would not have let my old girl (26 years) in the shed without proper cooling fluid. Protection until minus 37 degr C.
About oil: I agree. And nothing but the best for my old girl. No el cheapo oil from the supermarket. She has her standards .....

The pulse generators did fine for 26 years. Not bad, IMO. But your theory sounds valid: when I chopped the plastic it was all very oily inside. The one that still worked was much harder to crack than the defective one. The magnet of the working one broke in two because of the violence needed to free the metal innerworks. *That* was a good day: I didn't expect I could re-use the metal. Me lucky-dog.

Time will tell if I did it right. There was no alternative: spareparts for my classic is a pain. My backup-plan was to mount hall-sensors and generate a pulse-generator-like signal ... with an AVR, of course. I am quite pleased that I could stick to the original concept. Although I did the trick with the Hall-sensors and mocking-up a pulse-generator-signal in my automotive days.

There is only one AVR on board now: to do the indicators. These are led-based now; the original indicators broke at the flex-joint. No replacement at a reasonable price. Ripp-offs plenty. And the transition to leds was a logical step.

Sensors are now being baked for the last time. When done I will do a calibration of the built-in NTC, for later reference. When the second AVR comes in. With a nice LCD. And *resistive* touchscreen. Guess why ;)

Cheers

Nard

Whoooo, ...... the brand that shall not be named ?!

Just kidding. A PIC ?