Panteltje's sign_pic page

Panteltje's sign_pic page

A PIC 18F14K22 programmed to drive 8 LEDs to display a text when rotated anti-clockwise on the end of a string.

In this version you can set the displayed text via the serial link, text is saved in EEPROM.

Click here to download sign_pic-0.4.tgz

The circuit diagram, I also build a small 1.2V to 5V voltage converter, with a start and stop button.
The PIC measures the battery voltage after a MOSFET switch, and if it is above about 1.075V sends a 'power good' signal to the converter.
Battery will discharge to about 1.075V, then completely switch off, got about 20 hours from this battery before recharging was needed.
That converter can also be used as a universal 1.2V to 5V converter, but it is designed for low output currents.
sign_pic circuit diagram

James Arthur was kind enough to process the drawing so it looks a bit more readable:
sign_pic enhanced circuit diagram

The hardware:
sign_pic hardware

The LEDs are normal LEDs, not high efficiency ones, and driven with about 18 mA each.
These are on only 10% of the time or less, so if you want super bright you could pulse better LEDs.
Total current consumption is about 18 mA at 12V input, good for 7 hours on a 9V [rechargeable] battery.
It is probably illegal to mount this on the side of the car and display text to people standing still on the sidewalk,
or special messages to speeders that fly past you.
I wonder if you could do aerial commercials that way.
Maybe displaying some 'Cola' could bring in advertising money.
The possibilities are endless, you could even do TV with 20 PICs, 16 LEDS per PIC, makes 320 TV lines....

In action, swung on the end of the cable:

Click here for some programs I make available under the GPL.

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