eFinder Build Instructions

Building your own eFinder is relatively easy. Just a little soldering is required and a box drilled and cut to take the display.

You will need a camera and lens. Currently the code only works with ZWO ASI and QHY cmos cameras. I recommend the ASI120MM-S.    A 50mm f1.8 cctv lens is ideal and relatively low cost.

The code has been primarily developed to work with telescopes controlled by a Nexus DSC. Each installation will be different though and I can provide some help in modifying the code to suit. Please contact me if you want the code. This isn’t a commercial product, so please be prepared for some ‘work in progress’ and bugs.

There are two variants currently, the preferred one connects to the Nexus DSC via USB, the other via Wifi. Only if your existing Nexus DSC USB port is being used (ie by ServoCat) then use the wifi variant.

Parts List - Processor box

1x Box. I suggest one of the commercial raspberry Pi cases, but if dew is a problem then use a sealed box. 

1x Raspberry Pi4b or Pi5 4GB

1x 32GB microSD card

1x ttl to USB cable (using the PL2303chipset) Not needed if wifi used to connect to the Nexus DSC.

Parts List - control & display box

1x Box. 100x60x25 mm is just big enough.

1x display module. 2.23" OLED Display Module for Raspberry Pi Pico

1x Raspberry Pi Pico

1x 5 way navigation switch.

1x USB to micro USB cable, perhaps 3m long

Piece or red plastic for display window 

assorted small screws and nuts.

Thats it! (Most of these parts are available from the Pi Hut)


The tables list the wiring required for each box. 

The OLED module plugs directly onto the Pi Pico. Just 6 wires needed from the Pico pins to the navigation switch.

Click here for a gallery of photos of the eFinder build

Screenshot 2023-05-28 at 12.41.14

© AstroKeith 2022