Simple 8 Channel ADC for Use with Radio-SkyPipe

The schematic below depicts an 8 channel 12 bit analog to digital converter (ADC) which will work with Radio-SkyPipe software. Pins 1 through 8 of the MAX 186 integrated circuit correspond to Channels 1 through 8. The 100 kilohm resistor to ground shown on Channel 1 (pin 1) should be repeated for all inputs even if there is no intention to utilize that many channels. The circuit attaches to the computer via the parallel port. The appropriate parallel port address must be selected in the Radio-SkyPipe software. All .1MF (microfarad) capacitors are non-polarized types, typically disc ceramic capacitors. They should be rated for at least 15 volts. The circuit may be powered by a battery or other external well filtered DC power supply. (You may order the MAX186 IC from Radio-Sky Publishing below on this page.)

The circuit may be built on a small IC type Radio-Shack breadboard circuit board. For this circuit, I recommend using a socket for the MAX 186 IC. Insert the IC in the socket only after the rest of the wiring has been completed and double checked for accuracy. Be especially careful to orient the IC so that the notch in in IC package corresponds to pins 1 and 20 of the socket.

The circuit will work in the Standard version of Radio-SkyPipe, but only Channel 1 will be available. The Pro-Upgrade allows you to use any number of channels up to 8. The channels used must be sequential. Analog inputs should be restricted to the 0 to 4.095 V range.

The optional 1 to 10 MF capacitor is only necessary if the power supply is not adequately filtered.

If you have already built the similar circuit for the 8 channel ADCMAX project, you can quickly modify it by changing just three connections to the DB-25 connector. Click here for instructions on modifying that circuit.

Back to Radio-SkyPipe Help

Radio-Sky Publishing Home