MountOne | PF Assembly.

Don't Panic!

This guide is 99% images.

Index.

Printed Parts.

These parts have been printed in PETG-CF on a Bambu Lab A1 Mini. For best results, dry your filament before use. 

Full details are in the PF Printed Parts Documentation.

Electronics & Fixings.

The PF Astrograph Hardware Pack includes the following required components & fixings.

  • Hexaxes GPIO Highjacker.
  • 13 x M5 20mm Screws for Plastic.
  • 4 x M2.5 Hex Standoffs.
  • 4 x M2.5 4mm Bolts.
  • 5 x M2 6mm Bolts.

Parts you will need to source yourself.

There are two versions of this astrograph. The difference is one uses the standard Raspberry Pi B form-factor, and the other the 4/5 Compute Module. Details of the differences can be found in the MountOne Electronics documentation. Both are covered in this guide.

If you have downloaded the MountOne PF CAD Pack, there is a full BOM inside.

We go through the software setup in the PF Astrograph Software documentation. This guide is solely for the purpose of the hardware assembly.

PineFeat Lens Controller.

Please follow the guide and instructions on the PineFeat website to assemble the lens controller.

Please note that the camera module will need to be positioned differently to the way shown in the guide, we will cover this shortly.

Place the lens controller assembly into the housing as shown. The release catch should sit centrally in the slot.

It may take some persuasion to push in. Do not use a persuader.

An M5 20mm Screw For Plastic clamps the lens controller, do not over tighten it.

Notice the position of the camera module. Adjust to match.

Install the remaining wires.

Compute Module Wi-Fi Antenna (Optional).

If you have chosen to go with the Compute Module for the extra wiffy, we shall now install the antenna.

Remove the antenna proper, nut and washers from the base.

Insert the base into the main housing making sure to align the hex.

Using tweezers or similar, install the washers and nut.

Tighten the nut.

Install the antenna and position so it can be folded away.

Test.

CM5 (Optional).

Please follow the manufacturers instructions to assemble the Compute Module into your chosen base-board.

Move the antenna lead out the way.

Install the CM5 using the supplied four M2.5 4mm Bolts.

Clip on the antenna to the Compute Module.

Raspberry Pi 4/5 (Optional).

I have preinstalled the Raspberry Pi 5 Active Cooler.

The GPIO Highjacker needs to go onto the RPi next.

Attach the Raspberry Pi to the housing using four M2.5 Standoffs.

Raspberry Pi M.2 HAT.

Secure using four M2.5 4mm Bolts.

GPS (Optional).

I'm using Adafruit's Ultimate GPS Module. Other modules are available.

Affix using two M2 6mm Bolts.

5V DC/DC Converter.

The design includes mounting for Pololu's D36V50F5. However, I have made a bracket for Waveshare's DC5-36-TO-DC3V3-5.

Install using three M2 6mm Bolts.

The Wiring.

There are a collection of wires that need to be made that go between the various modules. Please refer to PineFeat's documentation for their connection to the GPIO Highjacker. Follow Adafruit's instructions for the GPS module, and Pololu's or Waveshare's for the DC/DC Converter.

There is a 12-way header that will connect to the MountOne. Please refer to the MountOne Electronics documentation for pin-outs. For this astrograph we will only need power and UART from the MaxPCB4, a total of four wires.

For the remainder of this guide we'll be following the instructions for the Compute Module. The wiring is easier to see when doing so.

Note: The Raspberry Pi can draw more than 1.5A from the DC/DC Converter. Make sure you use higher-rated (~5A) wire for the power from the DC/DC Converter to the Raspberry Pi. Using the incorrect cable can result in low voltage warnings.

For the Compute Module version of the GPIO Highjacker I have cut off the pins on the extender and covered the stubs with kapton tape.

  • UART0 - GPS.
  • UART3 - PineFeat Lens Controller.
  • UART4 - MaxPCB4 UART.

Note that the PineFeat Lens Controller requires both a 3.3v and 5v connection. Also connect Tx on one module to Rx on the other module.

Using four M5 20mm Screws For Plastics, install the lens controller module into the main housing.

The Cover.

The cover is held on with two M5 20mm Screws For Plastic.

Careful with the cables.

For specifics on which lenses to use, visit PineFeat's website. I recommend getting a second-hand prime lens.

Mounting The Astrograph.

Remove the cover and lens from the astrograph. Obviously you'll need to have assembled and tested the MountOne before doing so.

Route the cables through the centre.

Mount the astrograph using six M5 20mm Screws For Plastic.

For easy access I am attaching the MountOne to a desk tripod. You can just as easily use a standard tripod, or the Printed Equatorial Tripod (PET).

Check the wiring again. Confirm everything is as it should be.

Connect the wiring to the astrograph.

If all is well, plug the power in.

There should be no magic smoke.

Confirm everything is working.

Power off the system (safely shutdown the Raspberry Pi first).

Refit the covers and lens.

Next, we will go through the Software.

Glamour Shots.

Continue to the PF Software Documentation.

Back to Main Documentation.