GD77 Hotspot - Bottom Charger Part Replacement

thingiverse

This is a replacement bottom part of the GD77 desktop charger, designed to be a DMR hotspot, with a Raspberry Pi Zero W fitted inside. You can also replace the original charger board by a cheap TP5100 one (photo provided). The hotspot functionnality is **only available** in the OpenGD77 <a href="https://github.com/rogerclarkmelbourne/OpenGD77" target="_blank">firmware</a> (<a href="https://opengd77.com/" target="_blank">forum</a>) You need to cut the small inner tabs on the upper charger part, as the walls of the bottom part are thicker than the original. **Ferrite beads (on both cables) are required to avoid EMI problems (like USB disabling).** - 1 Mini360 DC-DC step down <a href="https://www.amazon.fr/gp/product/B07G4FM6ZW/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1" target="_blank">converter</a> (RPi power supply), - 1 power <a href="https://www.amazon.fr/gp/product/B07C4LYDHV/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1" target="_blank">switch</a>, - 1 Raspberry Pi Zero W, - 1 SDCard to install Pi-Star, - 2 MicroUSB male connectors, - 1 GD77 programming <a href="https://www.amazon.fr/gp/product/B01C89G9H8/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1" target="_blank">cable</a> (shortened to avoid EMI), - Adhesive copper foil band, - Wires, - 8 * M2 screws (various length 3 to 6mm, reuse the original 4 ones to assemble top and bottom charger parts). You need to put a copper foil layer under the RPi (between the bottom and the *Pi-Shield* parts), and also above it, between the shield parts, both connected to ground. **The FreeCAD files are provided**.