Thursday, October 15, 2009
Tuesday, October 6, 2009
OK, here it is. 5 inputs, 16 switched outputs, & 3, 5, & 12 volt power taps. I'm not going to give a step by step how-to because for as wild as it looks, it's really pretty simple.
The TTL signal from the parallel port pins travel through the small gauge wire to the circuit board, through the 1k resistor, and to the base pin of the transistor. The emitter of the transistor is connected to ground. The collector of the transistor connects to one side of the relay coil, & the other side of the coil connects to +12 volts. There's a diode across the coil of the relay, with the stripe toward the side connected to +12 volts. When VSA activates the pin the transistor allows current to pass from the collector to the emitter, completing the circuit and triggering the relay.
The inputs for MonkeyBasic's Helmsman, pins 10, 11, 12, 13, 15, & ground, are brought out to the barrier strip on one end of the enclosure. The other end of the enclosure has ground and power pins fed by a PC power supply, connected through a hacked PC power supply extension.
That's pretty much it. Now all I have to do is design my yard display & decide what to control. Shouldn't be a problem - I've got two whole weeks...
Posted by Jason at 9:12 PM