Larry (Mr.Optimization)

I work with bits, bytes and pixels. I'm also pretty good at optimizing code. Lately I've been doing a lot of proof of concepts for clients. I share my personal projects on GitHub here: https://github.com/bitbank2

I started programming as a teen in the late 70's with 8-bit micros.

Knowledge is to be shared, not hoarded.

Github: https://github.com/bitbank2
Blog: https://bitbanksoftware.blogspot.com
Buy me a coffee: https://ko-fi.com/bitbank

Public Key

npub1cujehsn48wkf5pz54cmmq92eahrfzu029fdel07v5eu993efxl0qrcjx7k

NIP-05 Address

fast_code_r_us_at_floss.social@momostr.pink

Profile Code

nprofile1qqsvwfvmcf6nhty6q322udasz4v7m353w84z5kulhlx2v7zjcu5n0hspz3mhxue69uhhyetvv9ujuerpd46hxtnfduqs6amnwvaz7tmwdaejumr0dsz2lyxf

Publishing to

nostr-pub.wellorder.net

relay.damus.io

nos.lol

Author Public Key

npub1cujehsn48wkf5pz54cmmq92eahrfzu029fdel07v5eu993efxl0qrcjx7k

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Last Notes

2026-05-04 18:02:36 UTC

New item arrived in today's mail - the Waveshare 4.2" ESP32-S3 RLCD (reflective) thing. It has a 400x300 ST7305 monochrome reflective LCD. It can update the display quickly in "high power" mode. The weird memory layout adds extra effort and latency to code, but it's manageable. I added support for it to my OneBitDisplay library (LCD_ST7305B).
https://cdn.masto.host/floss/media_attachments/files/116/517/615/265/307/569/original/2edfd0440cc4b522.jpeg

2026-05-02 15:12:14 UTC

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Tjpg is functional, but much slower. Your device has the ESP32-S3 which has advanced CPU instructions which can accelerate certain tasks. I use them in my JPEG library to speed up decoding. For 6k images, speed is not that much of a concern.

2026-05-02 15:01:42 UTC

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Are you using JPEGDEC with the S3 SIMD enabled?

2026-04-14 21:10:21 UTC

New in this week's mail - the Xteink X3. A teeny, tiny e-book reader. The hardware is smaller, yet more advanced that the X4. I added 1-bit B/W and 2-bit grayscale support for it to my bb_epaper library.
https://cdn.masto.host/floss/media_attachments/files/116/405/106/062/928/083/original/30c1aae28f10bd0c.webp

2026-02-18 19:17:56 UTC

@npub1jjf…jh0u I guess I missed when you added non-RPI devices to your pinout site. Thanks 🎉
https://esp32c3.pinout.xyz/

2026-02-16 10:28:57 UTC

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You mean the kind with Eink displays? I'm working on those. What is your must-have feature? Portability? Large display? Battery life?

2026-01-12 16:03:24 UTC

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To clarify...besides spending lots of quarters on Frogger when it came out (1981), not too long ago I also wrote emulators for most versions of it.

2026-01-12 11:48:50 UTC

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The 'real' Frogger (coin-op) didn't let you do that.

2025-11-13 11:15:43 UTC

New idea - parallel Eink displays driven by a Raspberry Pi (or equivalent Linux SBC). What's the benefit? The RPI is inexpensive and much more powerful than any ESP32. It can chew through pixels much faster and do more interesting things with the display. The PCB cost is reduced since the RPI is doing all of the heavy lifting. Thoughts?
https://youtube.com/shorts/LwGyGYwzwRU?feature=share

2025-10-26 20:56:12 UTC

Something new (for me) today. I enhanced some existing #Golang code. I have never seen Go before today. I can see the appeal - you get to choose to run it interpreted or compiled. I'm not going to switch to using it on the daily, but I can see where it might come in handy.

2025-09-26 19:15:46 UTC

This looks like a great project; I hope it's affordable:
https://www.crowdsupply.com/open-tools/open-printer

2025-03-12 13:17:47 UTC

The more I use Python, the more I understand why the performance is poor - it abstracts away so much of how a computer actually works that it makes it "business as usual" to duplicate/convert/enlarge data at every step of your code. When the data is large and the code bogs down, that's when you're forced to examine all of the memory mismanagement.

2025-02-23 10:58:06 UTC

Here's the premise to the software optimization course I'm creating. Does it resonate with you?
https://cdn.masto.host/floss/media_attachments/files/114/052/841/577/725/034/original/a6d9dfe33291e90f.png

2025-02-12 10:12:45 UTC

More emails with requests for free tech support today. The general form is "I found your library and I would like it to work on my hardware". It's pretty clear that the request is from someone with little experience in embedded HW/SW. I politely tell them that it isn't a simple question/response and that if they would like, they can engage me for paid consulting services. Is this how other people respond to such requests?

2025-02-03 17:55:17 UTC

Here's a short video of the new code I was talking about for FastEPD. It shows partial updates (fast, no flashing), 4-bpp grayscale (slow w/flashing) and finally a regional update (new) which allows a full update of either 1 or 4-bpp to occur without disturbing other pixels. The new feature is not ready to release yet, but looking good so far.
https://youtu.be/wXsfpUWcFxU

2025-01-23 14:31:34 UTC

I'm working on a new idea for an open source project to submit for a grant (NLnet). This idea would be a comprehensive embedded device simulator for MacOS that would accelerate embedded software development by simulating displays and sensors and allowing faster edit/compile/debug along with real profiling. Who would find this useful?

2024-11-13 10:00:19 UTC

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

2024-11-04 12:49:32 UTC

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The physics of e-paper is really complex and it's impressive how the controller hides so much of the details from users. The partial update situation is not intuitive and I tried to document it well in my examples, but it's definitely not obvious how to make use of it. Maybe bb_epaper can be the C layer that offers all options and put a pretty Python API on top. This will get you consistency across Arduino and RPI in both C and Python.

2024-11-04 11:52:45 UTC

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?

2024-10-20 18:25:43 UTC

Conway's game of life on e-paper? Sure, why not?
https://youtu.be/mdOq_wnun_U

2024-09-30 07:29:54 UTC

I spent some time over the weekend on my e-paper library and added 90 degree rotation to the bufferless 8 and 16-pixel font. It's hard to know how far to go with all of these features because the code size grows as well and that needs to stay 'slim' for constrained MCUs.
https://cdn.masto.host/floss/media_attachments/files/113/225/325/101/791/948/original/df69dffb06330c3a.jpg

2024-09-18 12:11:07 UTC

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I've got plenty of fun coding to keep me busy, but the **paid** coding is a mental grind today.

2024-09-18 12:05:58 UTC

...Still waiting for today's coding 'flow' to begin. In the mean time, scroll scroll scroll away the day 😀

2024-09-15 18:41:30 UTC

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Here it is - this is the feel-good bit of simple code I needed to write today. It allows 1-bit graphics to be written directly to e-paper frame buffers at any bit position. In other words, a setup with no local frame buffer can draw sprites or characters at any X position directly into the display's internal memory, not just on byte boundaries.
https://cdn.masto.host/floss/media_attachments/files/113/143/025/835/273/667/original/cd54d2991ec2b4e8.png
https://cdn.masto.host/floss/media_attachments/files/113/143/031/198/606/133/original/cc218f8ebe3f20d6.jpg

2024-09-15 17:07:09 UTC

Today is a good day to write 50 or so lines of C code that does something fun/amazing and gives you that dopamine rush instead of doomscrolling.

2024-09-13 10:21:47 UTC

My friend Martin and I are working on a new ESP32-C6 PCB to be the basis of some super low power #eink applications. We can't compete with the prices on AliExpress, but it would be affordable and probably sold through Tindie. Does this interest anyone?
https://cdn.masto.host/floss/media_attachments/files/113/129/742/264/449/254/original/c9e46319f8695233.jpeg

2024-09-09 10:54:58 UTC

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I found this GitHub repo with what appears to be the Hershey vector fonts converted to TTF:
https://github.com/yangcht/Hershey_font_TTF
I did a test on the AVHersheyComplexHeavy to a 40pt bitmap font (characters 32-127) and the result with my "BBF" format is 5228 bytes.

2024-09-09 08:01:27 UTC

I think my Group5 compression and font scheme are stable enough to turn into an Arduino library. I still haven't sorted the license situation, but that's not stopping me from writing and testing the wrapper classes.

2024-08-25 18:24:46 UTC

OMG - my compressed font idea worked on the first try. It took about 8 lines of C code to add support to bb_spi_lcd. This 70 point Roboto_Black font (digits and colon only) are stored in 1K of FLASH and need 256 bytes of RAM to decode.
https://cdn.masto.host/floss/media_attachments/files/113/024/056/242/220/406/original/781d9d841e9bbd9f.jpg

2024-08-24 18:02:26 UTC

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Only occurs in PULL-DOWN mode and with some other very specific conditions met. Will never occur in any of my use cases.

2024-08-24 08:46:28 UTC

I designed little breakout PCBs for the @npub1e4c…r4kh Xiao footprint. It gives you 2 push buttons, a QWIIC connector, 4-pin OLED header and 8-pin color LCD header. My friend Martin is testing selling them through his store here:
https://www.tindie.com/products/fasani/xiao-adapter-board-with-qwiic-display-connectors/
It's really hard to sell low priced items these days because of the labor and shipping costs. The actual item costs very little, but selling to individuals is very inefficient. Maybe someone here has a better idea for selling this type of item.

2024-08-17 10:54:35 UTC

Here's a full screen animated GIF running on my latest AnimatedGIF library code (easily compiled on the Pico 2 without modification). The PR2040 struggled to run it at full speed, but the RP2350 can do it without overclocking.
https://youtu.be/XfKLrqwvwwM

2024-08-17 10:23:42 UTC

The #RP2350 impresses me again today. I ported my 8-bit parallel LCD code from Arduino to the Pico SDK in a matter of minutes and it just works. The PIO code required zero modifications from the RP2040 version. Will have a video demo later today.

2024-08-09 11:19:59 UTC

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Any idea when this will be integrated into an Arduino board support package?