I just received a case from China today, that Roma had shown earlier. Sometime later I noted a couple of supplier prices (Under $5) and the possibility of squeezing an LCD under the window. A month later I have the case and 2.2" (240x320 pix) LCD, and was pleased to find the LCD fits perfectly.
How will the UI look on a 240x320 display ? (assuming sharp youthful vision) uses an ILI9341 driver.
I positioned a couple of example Chinese rotary encoders to show the fit, note the common one in the back has no mounting threads, I used the one on the right (I believe 30 pulses/rev) that comes with resistors on a board, I used de-bounce caps on 1/2 of the encoders last time and experience no trouble without them. (an occasional extra pulse can go unnoticed in this application)
The LCD screen ends up about 4mm below the plastic window.
Notice the pcb thickness grooves and registration pins for the hat this mystery design used. (I assume it’s surplus from a discontinued product, though the Pi 4 option suggests it’s not an old design).
The Pi mounting in the base has just 2 mounting screw holes, (their hat may have provided additional holding force)
All the Pi connectors and SD socket are accessible, there is just an 8mm wide gap next to the header where something could be squeezed in.
I show the Audio Injector Zero board mounted in the Pi, it’s cheapest 24 bit In/Out board ($16.90 Amazon prime/FBA) and allows more connector customizing options, the original Injector board shown in the first image is tough to fit into a rigid case, you may have to cut a slot for the connectors and pot on one side and use an external bezel to close them in.
The Odd Box Design is for DIN Rail Mounting
The Raspberry Pi’s are being used for energy monitoring applications, they might show up in solar energy utility closets.
Example Product Links for the incurably curious 1 … 2 … 3 … 4 … 5 … 6 … 7
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I just wanted to note one possible alternative to the port expander is the MPR121 I2C Capacitive touch 12 input chip whose pins can also be programmed as GPIO connections, it could do the encoder interface as well as handling a row of panel buttons.
1 board delivered for $2.33 (4 for $4.60)
These boards might be handy for a controller project, you can have 48 inputs using the 4 different I2C addresses available. Adafruit Writeup . . . Sparkfun
( You don’t see capacitive touch controls in pro concert gear.
Well perhaps not since the Wasp/Hornet which some non keyboard players still liked for the unique sound, though there were stories of it breaking out a random melody when the concert hall got sweaty)
This plastic case has a keyhole wall mount on the back (hinting at the original product application) this might be OK for semi permanent attachment to an existing synth. with some sort of external mount adapter.
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I bought a few of the first generation Google Voice kits to cannibalize when they were being dumped (Ver 2 uses a Pi Zero and is sold through Target)
$2.99 Google Voice Kit at Microcenter
I never expected to be using the fold up box, but the 9.5cm cube makes an interesting fit challenge.
I had the idea of a minimal cost pedal-board, etc for homeless street musicians, perhaps lent out by a shelter. (I was thinking the red game button on the top could play a celebratory sound when someone makes a donation.)
I discovered the space set aside for a speaker is just enough for a custom open frame battery pack (a standard one is a bit too thick) using a 2.1 A charge/management board with a power gauge. The broken out power connectors could charge a phone in a bind (note the sloppy hot glue used to strain relief the wires tacked onto the USB output)
1/2 way done I plan to use a passive circuit to match a guitar to the microphone input of the Audio Injector Zero (which has a 20db boost option in the Pi control panel)
Though this could act as a headless Zynthian, I am testing this box with a MOD Clone that’s pre-configured to act as a hot spot with VNC and Bluetooth activated, they have a phone Bluetooth app that performance controls the MOD.
I proposed in a previous post, upgrading this sort of die cut cardboard box by using corrugated plastic (like some sign boards use) instead.
Better moisture tolerance while still letting WiFi/Bluetooth pass.