Hardware Layout#
While ZynthboxOS will run just fine on a raw raspberry pi (check the Building and Installing guide to see how to do that for yourself), the best experience will be when using it with the hardware designed to complement it all: The Box. This chapter describes the layout of that hardware. If you already have a kit and would like to put it together, that's what the Build Guide is for.
In addition to the Raspberry Pi 5 on which the software runs, the box is made up of a number of components, which is what this document describes. Each component, in turn, also links to the relevant files in the hardware repository that you would need to print your own board and construct it yourself, either from scratch, or by purchasing the individual parts from some pcb manufacturer. It is worth noting at this point that you do not have to do this: If you would like, we offer pre-built boxes, and we also offer kits where all you need is to put it together (no soldering required), as well as kits where you get to do that soldering yourself. You can find all that in our store.
If you just want to dig in and look around, the kicad files for the project can all be found in the kicad subfolder of the project, but the following attempts to describe this in some further detail, with the main project file being Z2_rpi4.kicad_pro.
Kicad Update
The project was created using an older version of Kicad (when it was created in 2021), which according to the version i installed (version 9.0.2) is out of date, and it updated the project files for me when i tried loading it up (haven't saved anything, just glanced at things for now). Not a big problem, but something that will need keeping in mind.
The Components#
The main components which make up your box are:
- The Raspberry Pi 5
- The Display assembly
- The Main IO PCB
- The Controller PCB
- The Case (top and bottom part)
- The Heat Sink
The main PCB with a Raspberry Pi 5 installed
The top PCB, with the display assembly installed
The Raspberry Pi 5#
This, hopefully obviously, is not something we have built: The Raspberry Pi 5 is a powerful single-board computer, and readily available to most people. Where to acquire one would depend greatly on your location, but handily, the Raspberry Pi Foundation offers a list of locations you can get it from.
The Display Assembly#
The display assembly is made by DWIN, and the full set of details can be found here in the hardware repository. This is a combination of a HDMI display, and a USB touch surface, and it is connected to the Main I/O PCB via a single 24-pin ribbon cable, to allow for easy disconnection, for servicing and general messing about.
A render of the Display Assembly
The main files describing this piece are (this is pretty raw, as more of the design work seems to have been done by DWIN directly):
- PCB Layout
- DWIN Questions
- DWIN Communication
- (further details to go here as we dig in deeper)
The Main IO PCB#
The Main I/O is essentially a very fancy Raspberry Pi HAT, which you mount the SBC onto in the usual manner, but which itself is then strapped into the base of the case, in what would from the point of view of the SBC seem to be upside-down. This is done to allow for the direct connection heat spreader attached to the bottom of the case to directly contact the Raspberry Pi's warm bits. While active cooling is, of course, more efficient for heat removal, this allows us to safely run the SBC without having a fan in the box, which, to a great many people (and frankly us included) just wouldn't be acceptable for most music gear.
A render of the Main I/O board PCB, with a Raspberry Pi and the heat sink attached
The main files which make up this piece are:
- Generated Gerber file: The original Gerber file, before being adjusted by PCBWay
- PCBWay Gerber file: For production, usable for sending to PCBWay. This seems to be the version downloaded from there (there are minor design flaws in the PCB layout, which PCBWay will offer to fix, and this seems to be the fixed version)
- PCB layout: The raw PCB layout
- Schematic: The schematics for the board's sections (also where the BOM would be created)
- (further details to go here as we dig in deeper)
The Controller PCB#
The Controller PCB is where all the buttons and knobs on top of the box are located. Similarly to the display assembly, it is connected to the Main I/O PCB via a single ribbon connection, which allows for the two to be easily disconnected for servicing and general messing about.
A render of the Controller board
The main files which make up this piece are:
- Generated Gerber file: The original Gerber file, before being adjusted by PCBWay
- PCBWay Gerber file: For production, usable for sending to PCBWay. This seems to be the version downloaded from there (there are minor design flaws in the PCB layout, which PCBWay will offer to fix, and this seems to be the fixed version)
- PCB layout (the raw PCB layout)
- Schematic: The schematic for the board's sections (also where the BOM would be created)
- (further details to go here as we dig in deeper)
The Case#
The case is designed to be created from two pieces of metal, and then having a number of standoffs and the like added, for a build which is simultaneously sleek and easy to work with.
The main files which make up this part of the equation are:
- (further details to go here as we dig in deeper)
The Heat Sink#
Originally created and envisioned by the Zynthian project for their V5 box, this metal block is designed to attach directly between the Raspberry Pi and the case, with the main PCB between them, functioning as a mix of standoffs and connector, allowing the bottom of the case to function as a passive heat sink.
- (further details to go here as we dig in deeper)
Thoughts on rework options#
- The current touch sensors for the knobs lacks a resistor to ensure they are less twitchy (which and where will need investigating, but this is where the ghost touches come from)
- Converting the board to accommodate a Raspberry Pi 5 SBC in place of the 4 it was originally designed for will want a model of the RPi5 to be sourced. A look around the internet suggests this is not yet a commonly available thing (i can find one for the CM5, available from the foundation, but haven't found one for the raw 5 - though a step file exists in the foundation's product information portal, which would likely be useful to someone who knows the tools).
- The above will also be required for the heat sink
- Switching from silicone pads to hotswap keyboard switches (with the argument being end-user flexibility in the feel of interacting with the box, and flexibility in home construction)
- A way to plug in a battery and mount it internally would be very neat and friendly to our users (like, what if we offer it as a non-standard option, with one of the various standard connectors for the purpose, so people can pick their own battery and just fit it in the box?)
Ordering from PCBWay#
When it comes to ordering one of these, at the moment we're looking at PCBWay for the main bits (this has a minimum order quantity of 5). While this process could be done manually, it is much, much simpler to use the PCBWay Plug-in for KiCad plugin, available directly from KiCad's Plugin And Content Manager's Fabrication plugins tab. Using this, perform the following steps from within KiCad, with the Z2_rpi4 project opened:
- Once you have installed the plugin, open up the Z2_rpi4 PCB (double-click on Z2_rpi4.kicad_pcb in the Project Files tree)
- Wait for the PCB Editor to open, and then click the PCB Way button at the end of the toolbar
- In the newly opened browser window, the quote form will have the various files uploaded by the plugin
- Scroll down to the Assembly Service section, and tick the box
- Fill in the amount (the minimum order is 5, and while the assembly service can fill in less than that, as we are making five PCBs, probably makes sense to also assemble five of them)
- Click "Calculate" to make sure things are properly up to date
- In the sidebar, make sure you've selected the appropriate shipping destination and service
- Click "Save to Cart", and agree to the popup's questions (nothing in our thing is illegal or restricted)
- The PCB and assembly is now in the cart, and awaiting a reply.
The Existing Gerber Files#
Originally, the way the boards were made was that PCBWay printed the PCB only, and then for the first five prototypes, the boards were soldered manually by someone. The next, larger set of prototypes also had the boards made by PCBWay, but the component assembly work was done by Eónica Solutions in Barcelona.
What this means is, ordering a new set of boards is possible (by simply submitting the old PCBWay Gerber files to them and ordering the boards), but a fully constructed board would require one of two options:
- Either someone will need to do that soldering work (some individual person, or Eónica Solutions again)
- Or the BOM needs to be completed in a manner usable by PCBWay. It is worth noting to this last option that this is work which optimally would want to be done anyway.
Display#
Ordering replacement display assemblies will require considerably more research, and likely require direct contact with DWIN again, or perhaps getting back in touch with jofemodo, to see where they are at with their displays. (worth noting that he currently has both arms in casts, having broken them falling off a ladder after working on some solar panels)