Guru
Joined: 16/09/2019
Location: United KingdomPosts: 4048
| Posted: 11:09am 18 Sep 2023 |
Hi Andrew,
Thanks for the interest and the questions.
We will look at adding for the next revision / FAQ, but in the meantime here are some answers:
@bigmik is the master of the photos, I'm sure he will oblige.
The Game*Mite is 99.95% a PicoMite so you can connect USB and use a serial terminal or MMEdit as per usual. To get to the MMBasic prompt you need to send a Ctrl-C or select "Exit to BASIC" from the main menu.
J1 is a 7x2 right-angle boxed male header bringing out all the unused GPIO: GP16-19, GP26-28. There are also solder jumpers to route GP20-21 to this header if you don't need the onboard audio. It also has 3xGND and 2xVCC (3v3), note there isn't 5V anywhere on the board unless being powered by USB. These pins are (I believe) sufficient to allow access to a limited combination of ADC,I2C0,I2C1,RxTx0 or SPI0 (shared with display and SD card). I believe it could be used for the simple DSO code currently being developed y @NPHighview and others and for a 6-channel logic analyser (@Volhout) though in the latter case you have to sacrifice or re-route the audio to other pins. We could have made more I/O available by copying the NES controller design and using a shift-register and additional pull-up resistors with the buttons, but we sacrificed that in the name of reduced complexity / component count.
I'm sure @bigmik can oblige. Though at less than 1 GBP per PCB I'm not sure it's a waste to use one as the backplate, especially since it is printed with useful information about OPTIONS and pin allocation.
That is up to the "clever shedders" and outside my pay grade.
A prominent constraint in the current design was to try and create something ergonomic that would still fit on a single 100mmx100mm PCB because JLCPCB will fabricate those incredibly cheaply.
However if you wanted to fit a case then you would probably want at least two PCBs:
Bottom: 100mmx100mm containing the top half of the current PCB with the Pico and other modules but in the bottom half instead of having the controller you would mount the speaker, battery and a header (c.f. J10) on which to mount the controller PCB (below).
Top: A 100mmx40mm PCB containing the controller.
This would allow the TFT and buttons to be put in approximately the same horizontal plane making it easier to enclose and provide the necessary cut-outs.
With the volume turned right down the device draws ~100 mA. With the volume cranked up (and sound playing) is draws ~200 mA. You can do the maths yourself with the recommended 1000 mAh battery ... though those are Chinese mAh, so ... I've not had one give up on me yet.
I'm guessing that has to be done by measuring VSYS (from the battery) and doing some mapping of V vs. remaining charge in software. Does GP29 carry that information (VSYS/3) ?
Not as the hardware is currently configured. I *think* you could patch one of the unallocated PWM pins to the LED pin on the TFT but I've never tried it. In the absence of an operating system each program would then have to be able to handle this independently or the firmware would need some serious hardware configuration specific titivating to monitor the GPIO allocated to the buttons.
I think so, though you might want a version of the WebMite firmware that includes the Game*Mite's modifications, or Peter would have to be persuaded of their general merit.
I know nothing!
Not for the Game*Mite, but perhaps it may serve as inspiration for another device. The Game*Mite uses the ILI9341 because of its ubiquity, low-cost, and also most importantly because its resolution is the same as the PicoMiteVGA which makes porting games between the two platforms easier. I believe the 3.2" is the biggest of the ILI9341 displays.
It looks like you can get similar right-angle DPDT but the PCB might need titivating to fit one.
You know a fellow Aussie who can provide
.Best wishes,
Tom
Edited 2023-09-19 19:24 by thwill