Quote:
Originally posted by Mike Alighieri
...So, we got this solution... at radioshack, you can buy a little double-pole rotary switch with 6 positions.
Good stuff,
Mike Alighieri
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Mike,
We used the same switch with a little twist. If you are good at bending metal without breaking it, you can disassemble the switch. Take the contact insulator from the back of the switch. You will notice two, "u" shaped contacts on the rotating insulator inside the body of the switch. Cut the
inner contact on just one of the contacts. Then take a look at the metal body of the switch and you will see the metal is dimpled in two places. The dimples are the travel stops for the rotating shaft. Crimp one of the dimples up and out of the way and reassemble the switch. You will now have an eleven position switch. Wire 9k resistors between each of the contacts around the outside of the switch. Add a 10K resistor to the end contact and attach the other end to the 5 volt power supply. Tie the bottom of the resistor string to ground. Add a wire between the two center contacts and take that common point to an analog input. What you will have is a switch that simulates a 100K pot swinging from just under 5 volts to ground with 11 distinct steps. We used this method to select up to 11 different auto modes on the player control box. We were able to then have 11 programs loaded in the robot software (custom circuit board) and ran which ever program seemed appropriate at the time.
BTW this is an old Ham Radio trick. I have a home brew antenna tuner that I use the same switch to select 11 different inductors. I hope Radio Shack doesn't catch on, they'll either jack the price or dump it.