Servo motor controller direct interface to laptop

GreenGiant83

I have a parallax servero controller. I want to interface is directly with my laptop. I have the standard (db9 i think??) serial cable that I use to connect to my basic stamp 2.· I need to know what pins I need to connect to the servo controllers input. I found this document

http://www.lammertbies.nl/comm/cable/RS-232.html

Looking at the null modem cable config, i was thinking it might a similar setup. Using pins 2, 3, and 5.· If so would 2 and 3 be + and - respectively, and 5 be for signal?

Thanks

allanlane5

The serial PSC is designed to connect directly to a BS2 BOE board. This means that the serial signal levels it expects are "TTL" -- in other words, 0 to 5 volts. The 'normal' RS-232 signaling levels are +- 10 volts. Thus, you can't connect it directly to a PC without some 'level shifter' hardware in the middle -- typically a MAX232 chip with 4 capacitors on a small circuit board.

I believe the USB version of the PSC was created so you COULD connect the USB version directly to a PC, without any additional circuitry in the way.

GreenGiant83

Thats cool, I can have my stamp relay the messages, I dont really want to message with another board.· There isn't anyway to pass all serial input to the stamp to controller is there?

I am planning on using my laptop to generate a sine wave and position 8 servos relative to the values.· The amplitude of the wave is dependant on a light sensor that I have setup with a capictor on a pin to measure RC time.· Since I dont think you can compute the sine of a number on the stamp, and the lack of decimal based numbers, I am generating the servo positions via my computer based on serial input from the stamp.

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