MEGAphone Hardware Module Progress Update

While I've been focusing on the software and case of late, work has been continuing on the hardware modules as well, as you can see below:

 

This post is really to give an check-in on everything that has got us to that point, and show the progress against the milestones -- and focusing just on the milestones.

k.2.2.4 Low-energy power-management module to minimise energy consumption of device, especially in low-power modes:  PCB Fabrication

l.2.2.5 Low-energy power-management module to minimise energy consumption of device, especially in low-power modes: Assembly

m.2.2.6 Low-energy power-management module to minimise energy consumption of device, especially in low-power modes: Testing

n.2.2.7 Low-energy power-management module to minimise energy consumption of device, especially in low-power modes: Revision

These are pretty simple to address: We've described the testing of the FPGA that sits on the carrier PCB in this blog post: https://c65gs.blogspot.com/2025/12/megaphone-power-management-fpga-and.html 

All that's left is to confirm that the carrier PCB functions correctly once assembled. Here it is assembled:

And... it doesn't work.  

After a pile of testing to figure out how a module that is mostly just 1:1 pin connections could be wrong, I discovered that I had wired one of the ports backwards. This means that pins A3 and B3 that are the USB UART are tied to 3.3V and GND, respectively.  Not conducive for a working UART.

Okay, fixed that now:

The correcting commit is https://github.com/MEGA65/megaphone-modular/commit/7a2151f767eb1be3f8f2eaac9641930a6c5fc54e, and the source files are at: https://github.com/MEGA65/megaphone-modular/tree/main/modules/icesugar-nano-carrier

s.2.3.5 Battery management and energy harvesting module to allow USB-C, intergrated solar panel and external 12/24V vehicle battery power sources, and efficient management of the integrated rechargeable battery: Assembly

t.2.3.6 Battery management and energy harvesting module to allow USB-C, intergrated solar panel and external 12/24V vehicle battery power sources, and efficient management of the integrated rechargeable battery: Testing

This one is also fairly simple to report on, but with less positive news.

We've assembled the module, but despite considerable testing and attempts at finding the problems with it, it refuses to work. This module was based on an existing open-source design, hence the "module in module" appearance.  We've now come to the conclusion that we will need to completely redesign this from scratch using the datasheets, so milestone u.2.3.7 is not yet achieved. 

aj. 2.6.2 External speaker and bluetooth headset interface module: Schematic

ak. 2.6.3 External speaker and bluetooth headset interface module: PCB layout

al. 2.6.4 External speaker and bluetooth headset interface module: PCB fabrication

am. 2.6.5 External speaker and bluetooth headset interface module: Assembly

These two modules have been designed and assembled, as we can see in the images below, based on the schematic and PCB designs on github: https://github.com/gardners/mega65-megaphone-hardware-modules/tree/main/modules/bluetooth

at. 2.7.4 Primary FPGA carrier module, leveraging off-the-shelf FPGA modules if at all possible: PCB Fabrication

au. 2.7.5 Primary FPGA carrier module, leveraging off-the-shelf FPGA modules if at all possible: Assembly

av. 2.7.6 Primary FPGA carrier module, leveraging off-the-shelf FPGA modules if at all possible: Testing

aw. 2.7.7 Primary FPGA carrier module, leveraging off-the-shelf FPGA modules if at all possible: Revision

This module has been assembled and confirmed to work. Again, it's a fairly simple pin-mapping module.  Schematic and PCB layouts in github at: https://github.com/gardners/mega65-megaphone-hardware-modules/tree/main/modules/te0725-carrier

 

ay 2.8.2 LCD panel interface module: Schematic

az 2.8.3 LCD panel interface module: PCB Layout

ba 2.8.4 LCD panel interface module: PCB Fabrication

bb 2.8.5 LCD panel interface module: Assembly 

The schematic and layout are in github as usual at https://github.com/gardners/mega65-megaphone-hardware-modules/tree/main/modules/lcd-panel, and the images below show the fabricated and assembled PCB, and confirmation of fit-testing with the LCD panel.

bf. 2.9.2 Auxiliary communications module, e.g., LoRa, ultra-sonic, infra-red or mm wave: Schematic 

bg. 2.9.3 Auxiliary communications module, e.g., LoRa, ultra-sonic, infra-red or mm wave: PCB Layout

bh. 2.9.4 Auxiliary communications module, e.g., LoRa, ultra-sonic, infra-red or mm wave: PCB Fabrication

bi. 2.9.5 Auxiliary communications module, e.g., LoRa, ultra-sonic, infra-red or mm wave: Assembly

bj. 2.9.6 Auxiliary communications module, e.g., LoRa, ultra-sonic, infra-red or mm wave: Testing

bk. 2.9.7 Auxiliary communications module, e.g., LoRa, ultra-sonic, infra-red or mm wave: Revision

This is another of the simpler modules, with just direct pin-to-pin mapping. The image below shows it assembled into the main carrier board.  Testing was performed by ensuring that the pin mappings are all valid.  Schematics and PCB layout as usual in gitlab at: https://github.com/gardners/mega65-megaphone-hardware-modules/tree/main/modules/lora

bm. 2.10.2 Main carrier board and assembly, into which the various modules connect: Schematic

bn. 2.10.2 Main carrier board and assembly, into which the various modules connect: PCB Layout 

bo. 2.10.2 Main carrier board and assembly, into which the various modules connect: PCB Fabrication 

bp. 2.10.2 Main carrier board and assembly, into which the various modules connect: Assembly

Here we again have mixed news: The carrier board has been assembled, but it's clear that we need substantial revisions on this, in part due to having placed some module recepticles up-side-down.  We will need to work out a way to make that harder to do by mistake when designing with this modular system.  Schematic and PCB layout on github as usual: https://github.com/gardners/mega65-megaphone-hardware-modules/tree/main/modules/main-carrier