Mecanique's internal bootloader OSC

[ScaleRobotics]

Not a problem Doug, glad it worked for you. By the way I love your project. http://www.harbornet.com/sunflower/pvdish.html

Charles and Bert have convinced me as well. So my next project will run on internal oscillator.

And for those really cheap, small projects, you can get away without a max232 chip with another modification to the source code. http://www.picbasic.co.uk/forum/show...2538#post82538

Walter

Edit: Here I am with my solar install:

[cncmachineguy]

Charles and Bert have convinced me as well. So my next project will run on internal oscillator.

Nice to know I can convince someone of something

welcome to the "inside"

[SUNFLOWER]

California solar, kudos scalerobotics. The solar dish is a dangerous autonomous robot. It must know where the sun is from a clock time/date algorithm and where the dish points. Otherwise, if the sun suddenly appears from behind a cloud then a rebel dish could melt rocks or start fires. I was once set on fire by walking into the invisible beam. It was like being hit with a 10 kW laser.

It appears the dish control system will cost $15, plus sensors $? and Pololu dual motor Hbridge TB6612FNG $8 for one.

The MAX232 is not so dear. Olimex make a populated PIC 40 carrier board ~ 1 @ $17, or 150 @ $13, or thousands w/o crystals @ <$10. Includes PIC 40 socket, MAX232, DB-9 plug, LM317 +3.3V / +5V power, status led, push button, 20 MHz crystal, reset button, ICSP, and circuit area for things like a DS1307 clock. Looks good for production start up with easy scale up.

http://www.olimex.com/dev/pic-p40.html

The business model is mass production from existing mass produced materials and parts all installed/maintained globally via local integration without central command and control. Local return on investment must be 20% (without subsidies) compared to current natural gas prices.

The huge and urgent objective is international global warming mitigation.

Best,
Doug

[Bruce]

Charles,

We have chamber-tested random units at -40C and 100C, about 30 units total.

Were you testing this by boot-loading with the internal osc and a serial loader, or just testing to see if the PIC failed at these temps?

If so - which PIC were you using? I've had problems in Colorado when the temperature fell below freezing with serial loaders using the internal osc. And more when the board was in an enclosure exposed to direct sun.

Just curious. That's pretty good if you were boot-loading with a serial loader using the internal osc at these temperatures.

[Charles Linquis]

Charles,


Were you testing this by boot-loading with the internal osc and a serial loader, or just testing to see if the PIC failed at these temps?

If so - which PIC were you using? I've had problems in Colorado when the temperature fell below freezing with serial loaders using the internal osc. And more when the board was in an enclosure exposed to direct sun.

Just curious. That's pretty good if you were boot-loading with a serial loader using the internal osc at these temperatures.

We were not actually boot-loading at those temps. We were, however, continuously doing serial I/O at 19,200 baud. No problems. Note that we were using 18LF2321's at 5V.
Many years ago, I found that some other chips (in the 16F series) were not nearly so accurate - or stable.

[Bruce]

Thanks Charles. I'll have to try an 18F part. I had tested this with 16F types. Never thought there would be that much difference with the internal osc on an 18F type, but I will test it. Solid comms with the internal osc at those temps is pretty amazing.

[Charles Linquis]

Different parts have different tolerances on the oscillator. Some of the newer 18F parts are really good.

[ScaleRobotics]

Otherwise, if the sun suddenly appears from behind a cloud then a rebel dish could melt rocks

Melting Rocks = Cool!!

The huge and urgent objective is international global warming mitigation.

Very Cool!!

I was once set on fire by walking into the invisible beam. It was like being hit with a 10 kW laser.

Most uncool!

Very nice project indeed. (And don't forget to wear your sun block!)

[SUNFLOWER]

Solar melted rocks made great visitor gifts.

We flashed hot dogs on sticks into carbon but could not get a marshmallow hot. The rules at Federal solar concentrator sites include, "Always wear white clothes and white caps".