Notices by Larry (Mr.Optimization) (fast_code_r_us@floss.social)

I added a new example to my FastEPD library today. It's not 100% done, but you can start playing with it if you have a M5Stack PaperS3. Here's a short video of it in action:

https://youtube.com/shorts/4gfZluva_18?feature=share

It allows you to navigate the files on the SD card and view (some) image files.

The video file is compiled into the code for this first demo; next I'll read it from the uSD card. This test is of a 22-second 320x240 30fps old Simpsons scene (1.8MB). It averages 2.7K bytes per frame (audio+video)

I added an ESP32-S3 player Arduino example to the pl_mpeg repo for testing. It's nearly able to play 320x240 30fps video w/audio at full speed. The audio is the source of the slowdown now. It's the floating point samples and having to convert them to 16-bit integers. That's the next area to work on - getting rid of the floating point math.

https://youtu.be/hO5Fm7-GFOo

Some quick observations about the ESP32-P4 PCB:
- The PSRAM is integrated into the SoC and is faster than other ESP32s.
- The MIPI DSI (LCD) output is a new bit of hardware and software. It allocates the frame buffer in PSRAM and needs a new API to flush the cache properly.
- It's faster than the ESP32-S3, but not dramatically. The STM32H7 is still much faster than the ESP32-P4
- It has some new 2D DMA I need to explore; it might allow some interesting graphics acceleration.

Here's a quick demo of what I achieved with my optimization of pl_mpeg. A 320x240 video running on the ESP32-S3 and averaging 74 FPS 👀

https://youtu.be/j0QUj42GYQY

The goal is to play any video this size at its rated speed (usually 24fps) on the ESP32-S3.

Thanks to a few helpful testers, my FastEPD library is rapidly supporting a lot more eink panels (8 and 16-bit parallel). One of the features I needed to add was the ability to flip the X and Y directions for certain (odd) panels. Here's a photo of the Y flip on a panel which doesn't need it.

My parallel e-paper library is nearly all fleshed out. This video shows the 3 main ways you can update the display (full update with flash black/white, faster regional update with flash and partial update with no flash).
https://youtu.be/UInzMlpk8ks

M5Stack PaperS3 running my (partially finished) bb_epdiy library:

https://youtu.be/8-cR3clCKIk

The same code also runs on @fasani 's EPDiy V7 PCB:

https://youtu.be/7P4nBP8v6do

In case you haven't seen it, I'm helping with the ZeroWriter project. I optimized the Inkplate library for a couple of their epaper PCBs. ZeroWriter 1.0 will ship with the Inkplate5V2 inside. By optimizing the code, it now has acceptable latency to be used as an electronic typewriter:

https://www.youtube.com/watch?v=Eu8y8mqh5r8

Today I made use of a tool I wrote several years ago. I wrote it to test performance of my code.

A new client is using an i.MX 6 (Cortex-A9) CPU for their product and my gcc_perf tool allowed them to see the direct benefit of being sensitive to the functioning of the CPU write buffer and in-cache vs DRAM latency:

https://github.com/bitbank2/gcc_perf

The first project (that I'm aware of) using my Group5 image compression has had some great success. The openepaperlink project from Aaron Christophel has successfully built the image decoder on a 8051 based electronic shelf label (a very constrained MCU). This reduced the image transmission time by 66% (same with the power). More details soon.

#epaper
#ESL

Besides the cost and speed of e-paper hardware, how do you feel about the software? I see the value of Python for a lot of users, but the tradeoffs for me are not worth it. When experimenting with Python on the Raspberry Pi, I found the following:
- Extra steps / problems encountered when setting up the environment
- Slow speeds (could be several reasons)
- Lack of features: the only exposed method is full refresh. This limits what you can do with e-paper.

Thoughts?

Conway's game of life on e-paper? Sure, why not?

https://youtu.be/mdOq_wnun_U

I added a similar web server example to my bb_epaper project. This one does image compression on the ESP32 through a self-hosted web interface. The user uploads a 1-bit per pixel Windows BMP file and gets back a Group5 (my compression) compressed file as either binary or C HEX values.

https://github.com/bitbank2/bb_epaper

The ESP32 is capable of doing quite a bit on its own. I'm sure I'll expand on this type of project in the near future.

I just added a new project to my "CYD_Projects" repo:

https://github.com/bitbank2/CYD_Projects

This one creates a web server on the ESP32 and allows you to upload JPEG images which get displayed on the LCD.

@jwildeboer What software are you using to drive it? Would you be willing to try my bb_epaper library?

For any #Pimoroni fans, I just confirmed that one of my bb_epaper configurations works on the InkywHAT 4.2" 400x300 B/W/R product. Now you can program your e-paper apps in native code. Try the rpi/examples/compressed_font example.
https://github.com/bitbank2/bb_epaper

@chris "Right to work" = "employees are head-count / chair-warmers"
Since interest rates rose about 18 months ago, big tech companies have had a convenient excuse to lay off 1000's even though they can easily afford to double the number of employees on payroll. "Shareholder perceived value" and "CEO compensation" are much more important to them these days.