ROADMAP

[Gadgetoid]

These are outstanding Interstate 75 issues that we've got a tentative interest in fixing:

• Interstate 75 Pixel Mapping pimoroni-pico#249
• Interstate75 - supporting more panel types pimoroni-pico#233
• Interstate 75 W, no global brightness function? pimoroni-pico#805
• I75W fails to activate wireless interface using MicroPython v1.24.0, picow v1.24.0-beta1 pimoroni-pico#1035
• Request for additional resolutions DISPLAY_INTERSTATE75_192X32 DISPLAY_INTERSTATE75_256X32 pimoroni-pico#988
• i75 + Pico W ever increasing memory usage pimoroni-pico#871

[tkreyche]

Please get the global brightness adjustment implemented. I believe this was possible in the Circuit Python build for the 2040 but that doesn't run on the 2350. So there are no other options. Experimenting with a hardware hack, don't know if it will work yet. I need to drive the panel brighter than your default pwm settings - why are you limiting it and not allowing adjustment? Increasing the volage over 5v helps a little but not much and is the wrong solution. If I want to burn out my LEDs early that should be my own decision.

[ansiwen]

@Gadgetoid Is this repository still active? I just bought a Interstate 75 W (2350) and the last release is quite old for a product still being sold. The Pico 2 W releases in https://github.com/pimoroni/pimoroni-pico-rp2350 is a lot more up-to-date, which I am using now, but they are lacking some I75W specialities. That's fine, I'm not using them anyway, but I'm just curious, what the plans are. Thanks!

[Gadgetoid]

quite old for a product still being sold

Wow, you're not wrong. Apparently I shut my eyes and 2025 just blew past.

I'm just curious, what the plans are. Thanks!

We've reinvented the wheel for graphics, again, and are working on a new product that uses the hub75 and this library. As such the development is plodding along behind the scenes but there are definitely things happening.

Was there anything specific you needed for an up-to-date MicroPython?

And @tkreyche

Please get the global brightness adjustment implemented.

This is more complicated to do well (and fast) than you'd think, but I have some ideas relating to regenerating the gamma LUTs so we get brightness control for "free" without adversely affecting dynamic range.

[ansiwen]

I'm just curious, what the plans are. Thanks!

We've reinvented the wheel for graphics, again, and are working on a new product that uses the hub75 and this library. As such the development is plodding along behind the scenes but there are definitely things happening.

Was there anything specific you needed for an up-to-date MicroPython?

@Gadgetoid thanks for the prompt response! No, as I said, I was just curious, because I saw the betas got released in short intervals and suddenly stopped a year ago, so I just wanted to make sure I am not missing something. As I said I'm fine with the Pico 2 W release for now, since it also has the hub75 module/driver included, which is my main interest.

In general (not micropython related) I have two things on my current wish list:

• possibility to render my own custom bitmap fonts with the hub75 driver (or a standalone hub75 PIO/DMA driver that I can use with a standard frambuffer)
• support for FM6373 LED driver (I got two 128x64 panels with these chips)

BTW: The Interstate 75 W (2350) is perfect! I couldn't find anything else with RP2350, WiFi, LED matrix power supply and 5v level shifters in a single package, and even for a good price. I hope you will restock them! :-)

Thanks again!

[Gadgetoid]

• possibility to render my own custom bitmap fonts with the hub75 driver (or a standalone hub75 PIO/DMA driver that I can use with a standard frambuffer)

This is something that our new PicoVector library can do well, and which I'll be migrating to i75 generally.

• support for FM6373 LED driver (I got two 128x64 panels with these chips)

Driving two 128x64 panels is around the tipping point where scanning out the pixel data becomes really cumbersome and we're working on a dual channel matrix driver - which works beautifully with very specific panels - in order to work around this.

Somewhere out there is an installation using pure C drivers running 5 x 32 x 32 panels (5120 pixels) across multiple Hub75 boards, and even that was close to the limit. There's a delicate balance of framerate, brightness and bit-depth (for high dynamic range gamma correction) to maintain.

Have you had any luck poking the panels from MicroPython? If they are electrically compatible then it should be possible to build a driver for them that just accepts the raw pixel data from PicoGraphics (memoryview(graphics)).

Otherwise I don't believe we stock or sell them, so I don't have access to any for testing. Got a link to the specs/datasheet?

[ansiwen]

• possibility to render my own custom bitmap fonts with the hub75 driver (or a standalone hub75 PIO/DMA driver that I can use with a standard frambuffer)

This is something that our new PicoVector library can do well, and which I'll be migrating to i75 generally.

@Gadgetoid vector library for bitmap fonts? I want to define each single pixels of the fonts (I want to recreate the font of our local public transportation displays).

• support for FM6373 LED driver (I got two 128x64 panels with these chips)

Driving two 128x64 panels is around the tipping point where scanning out the pixel data becomes really cumbersome and we're working on a dual channel matrix driver - which works beautifully with very specific panels - in order to work around this.

But your "Starter Kit" includes two 128x64 panels. I assumed that must work well with the RP2350 then?

The FM6373 are so-called E-PWM panels, so they should be less demanding, because you don't need to do the BCM for brighness levels anymore, IIUC. The only driver that I could find that implements it since recently is for STM32: https://github.com/board707/DMD_STM32

Have you had any luck poking the panels from MicroPython? If they are electrically compatible then it should be possible to build a driver for them that just accepts the raw pixel data from PicoGraphics (memoryview(graphics)).

Oh, with memoryview(graphics) I can access the raw framebuffer? I'm new to micropython, I had no idea. Just googled it. (That was a third point on my wishlist, that I forgot to mention: after I decoded a picture from a file, I want to move it without decoding it again for every frame.)

Otherwise I don't believe we stock or sell them, so I don't have access to any for testing. Got a link to the specs/datasheet?

Here someone found a data-sheet, but it's quite sparse:
mrcodetastic/ESP32-HUB75-MatrixPanel-DMA#642 (comment)

[Gadgetoid]

vector library for bitmap fonts?

It's predominately vector, but it also does pixelly things 😆 ie: all the pixel fonts are proper pixel fonts.

Our current PicoGraphics library supports custom pixel fonts, but it's much more difficult to create the necessary data files. Some details here: https://github.com/pimoroni/pimoroni-pico/releases/tag/v1.20.3

The font creator tool - pgfutil - never got the love it needed, but it does work.

The FM6373 are so-called E-PWM panels, so they should be less demanding, because you don't need to do the BCM for brighness levels anymore, IIUC

Interesting, so just send them brightness levels in presumably 8-bit (like a chain of APA102s but not) and they'll do the rest- that feels very accomplishable with a small Python library.

But your "Starter Kit" includes two 128x64 panels. I assumed that must work well with the RP2350 then?

Edit: Missed this. Yes RP2350 makes a big difference, but it still falls short of our lofty expectations 😆 actually I think the 5x32x32 I was thinking of also used RP2040-based boards. I'm definitely losing the plot a little.

It's academic, though, because if FM6373 takes basically all of the load off displaying an image (I still don't fully understand them and data seems scant but I'm looking into it) then both the 2040 and 2350 should be able to handle more pixels without significant framerate/brightness compromise. It looks like it supports 16 colums x 64 rows at a time, with an input pulse to advance the row. There's enough RAM for twice this, though, so that hints at double-buffering support (write a frame while the other is displaying).

It's also possible that the panel is just not electrically compatible with existing Hub75 controllers. I'm intrigued though.