At right is shown the Mk3 and Mk1 control boxes. The Mk3 (on the left) is built into the smallest standard probably achievable. This requires some dexterity and others may opt for a larger box!
At least one side of the box should be made from plastic, allowing the Raspberry Pi wifi signal to be accessed.
The front panel has a power switch, and 3 LEDs. These show on/off, Nexus serial link status and tracking status.
The Raspberry Pi is mounted such that its USB and Ethernet ports are directly accessible. Also a 8P8C jack (RJ45) for the Nexus serial (+USB option) cable.
On the rear are the connectors for attaching the motors, 12 Vdc power and the telescope select switch.
Other types of connectors could be used, indeed they could be omitted and connections made via flying leads.
Control Box Components
The main components are shown here.
Control Box Schematic
Connections shown in red are only required for the eFinder option (mk3eF).
Wiring List mk3
For the mk3eF a USB connection is required to the Nexus DSC. So from now on the 6p6c jack is replaced with a 8p8c RJ45 jack. The wiring is as shown below,
Parts List
1x Box. Suggested ….
Hammond 1455P1601xx plus 1455PPLxxx plastic ends. Suitable for panel mounted connectors on rear and front panel. xx = colour code
1x Raspberry Pi 4b 4GB
1x Phidget HUB0000 or HUB0001_0
2x Phidget 4A stepper STC1003_1
2x Phidget 3003_0 10cm cables
1x 12Vdc to 5Vdc 3A (buck) converter
1x USB A to Mini USB (short!)
3x 3mm red LEDs3x 1k resistors (vary according to brightness wanted)
1x MAX3232 IC mounted on mini pcb. (TTL to RS232 converter)
1x 40 pin GPIO breakout module (soldered or screw terminal as preferred)
1x 8P8C RJ11 socket (panel mounted if preferred)
2x 4pin motor sockets and plugs (panel mounted if preferred)
1x 5.5/2.1mm dc power socket.
2x SPST switch (front panel power switch and telescope select switch)
assorted small screws and nuts.
Control Box software
An microSD card is required loaded with the complete ScopeDog software. (Available for a small charge - contact me)
Click here for details of the Hand Box