ATM - Martin Cibulski - 2004-06-20
Start > Microcontroller based telescope driver IV > Hardware


Hardware Description


Mainboard Connections

Around the PCB layout one can see the names of the connectors with pin numbers.


Power

This is the 24 V power connector.

PinSignal
1Plus, 24 V
2Minus, Ground

Stepper 1 and 2

Stepper motor connections.

PinSignal
1Motor coil 1, plus
2Motor coil 1, minus
3Motor coil 2, minus
4Motor coil 2, plus
5Ground

Handbox

Two shift registers in the handbox are controlled from the main CPU.

PinSignal
1Ground
2Power, 24 V
3Port A0, output, shift data + LCD register select
4Port A1, output, shift clock + LCD R/W signal
5Port A2, output, parallel output pulse + LCD enable signal
6Port A3, input, LCD busy signal
7Port A4, output, parallel input pulse
8Port A5, input, shift data (buttons)
9Port D7, output, LED on/off
10not connected

RS232

RS232 pins are numbered differently to make Sub-D crimp connections possible.

PinSignal
1not connected
2Receive
3Send
4not connected
5Ground
6not connected
7not connected
8not connected
9not connected
10not connected

Expansion Port

This connection is the Two Wire Interface of the AVR processor which can handle the I2C bus protocol. This connection is currently not used in the software.
A possible application might be controlling two more motors (field derotator, focuser) from a second board connected here.

PinSignal
1Ground
2Power +5V
3Ground
4Port D1, SDA
5Ground
6Port D0, SCL
7Ground
8Port D6, output, clock pulse
9Ground
10Power +24V

mc_4_mainboard_connections.gif
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