# Autoguide

The computerized altazimuth newtonian system can accept autoguider input.

The autoguider needs to supply a relay for each direction, or, a +5 VDC TTL signal for each direction, or, a serial connection sending LX200 protocol commands.

If using a relay box, wire the interface circuit such that when a relay closes, a +5VDC TTL signal is supplied as follows:
If using a control signal, tie the control signals so that the control signal going to logical high raises the input voltage to a +5VDC level as follows:

(this scheme mirrors the four direction buttons on the hand paddle)

- up or north: to pin 13 of the parallel port,
- down or south: to pin 12 of the parallel port,
- left or counterclockwise: to pin 10 of the parallel port,
- right or clockwise: to pins 13 and 12 of the parallel port.

### To operate:

- 1. Put the telescope control program hand paddle mode into one of the guide modes. Set the speed of the guiding corrections by adjusting the microstepping guide speed.
- 2. Orient the autoguider by rotating it so that the autoguider's up and down correspond to the telescope's autoguider.
- 3. Calibrate the autoguider.
- 4. Initiate guide corrections by the telescope control program by momentarily flipping the hand paddle mode switch to the left and then center the switch.
- 5. Start the autoguider.

All guide functionality continues to exist with the autoguider on. For instance, in guide+stay mode, flipping the hand paddle mode switch momentarily to the right will calculate drift, and null the telescope's drift. Immediately re-initiate telescope control program guiding by momentarily flipping the hand paddle mode switch to the left and then center the switch. In guide+record mode, a record is kept of the autoguider's corrections.

The hand paddle can continue to be used. Pressing a direction button will add its guiding correction to the autoguider.

### Guide arrangements include:

- piggyback guide scope
- off-axis guider
- intercept guider
- built-in guider chip ala ST7, ST8

- return to top
- continue onto 'Configuring the Software'
...by Mel Bartels