gregdavill - Network

Hide an auto-routed mess with this one simple trick. 🤪

Hide an auto-routed mess with this one simple trick. 🤪

Designed this board years ago, and finally ordered it. The pattern looks really cool on the physical...

Designed this board years ago, and finally ordered it. The pattern looks really cool on the physical boards.

https://github.com/gregdavill/advent-calendar-of-circuits-2020/tree/main/syzygy-flir-tau2

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35 •

Circuit boards have arrived ✨

Circuit boards have arrived ✨

I've used the ecpbreaker on a few projects, as a "USB pipe to/from .*" The singular prototype I've got has had a fair bit...

I've used the ecpbreaker on a few projects, as a "USB pipe to/from .*"

The singular prototype I've got has had a fair bit of local rework done. I'd planned to update the designs, in the process I also swapped packages and added routing for the ECP5 serdes to support USB SS.

Got a little carried away in inkscape on the silkscreen for this ESP32-C3 based controller board for controlling some flipdot display...

Got a little carried away in inkscape on the silkscreen for this ESP32-C3 based controller board for controlling some flipdot display modules.

Using this plugin from PCM, which makes the KiCad to blender process super easy: https://github.com/30350n/pcb2blender

Turns out if your riscv code causes an exception before the handler is configured and the core triggers a load access exception, you’ll be...

Turns out if your riscv code causes an exception before the handler is configured and the core triggers a load access exception, you’ll be in a loop that never exits. Apologies for creating… checks notes… 1.8TB trace logs 😵‍💫🫢

When you don't have the exact part... Just place a parallel combination 🙃

When you don't have the exact part... Just place a parallel combination 🙃

Importing an image into KiCad isn't a new feature. But it's super handy for reverse engineering a design. 🐍Would be handy if it...

Importing an image into KiCad isn't a new feature. But it's super handy for reverse engineering a design. 🐍

Would be handy if it was a touch easier to calibrate the exact image size I just adjusted scale until parts started lining up, then locked the image.

Not sure exactly what I’ll do with this now. But I want to refactor my MIPI code a lot to make it more reusable. Knowing the init sequence...

Not sure exactly what I’ll do with this now. But I want to refactor my MIPI code a lot to make it more reusable. Knowing the init sequence that worked on this panel should let me build a simple Linux board with CM4/CM5 or allwinner SoC. Which would let me ultimately use these panels as ethernet connected wall mounted Home Assistant displays.

In tweaking my initial code I noticed I could get into modes where the panel didn’t turn on. After properly simulating the init sequence I...

In tweaking my initial code I noticed I could get into modes where the panel didn’t turn on. After properly simulating the init sequence I found a bug casing lanes to get out of sync 🤪

Fixing that still proved insufficient. Eventually found a different set of init values that actually worked! Then after bumping clock frequency and adjusting frame timing I got a perfect test pattern. This panel is now running RGB888, over a (reasonably slow) 100Mhz MIPI link 🥳

Motivated by this success I decided to revisit my attempts to drive a MIPI version of a similar panel. Unfortunately they’re not from the...

Motivated by this success I decided to revisit my attempts to drive a MIPI version of a similar panel. Unfortunately they’re not from the same manufacturer, and don’t use a common controller.

After updating my old migen/litex based code, I added proper support for multiple lanes, and found similar init code for this panel. After a day or two managed to get something displaying. But it was clear the panel was not happy (edges darkening over time, colours not right, etc)

As a holiday project I figured I’d take a look at these 4” LCD panels. This is a 720x720 pixel with 18bit RGB666 interface. Following...

As a holiday project I figured I’d take a look at these 4” LCD panels. This is a 720x720 pixel with 18bit RGB666 interface.

Following the manufacturers example code I found a binary blob of configuration register unit values I needed to send to the display before it would even display anything. 🥲

Once I had the display on a bit more tweaking was needed to frame timing to get correct pixel data.

Finally hooked it up to a HyperRAM backed frame buffer to get full colour images displayed

Assembly note: "Resistor tried to escape"... It tried to do what?! 🏃

Assembly note: "Resistor tried to escape"

... It tried to do what?! 🏃

Something I should have tried out sooner, making use of the USB 3.0 parts of the luna USB stack on the ButterStick FPGA board.Spun up a...

Something I should have tried out sooner, making use of the USB 3.0 parts of the luna USB stack on the ButterStick FPGA board.

Spun up a simple breakout with a PD controller and data lanes connected to a Type-C.

The LUNA SS code has some bitrot for ECP5 support, but did manage to get it enumerating over the weekend! 😍

All accomplished using the ECP5's built-in 5Gbps serdes blocks and fantastic opensource tools: nextpnr+Yosys, amaranth and LUNA gateware. 🥳🙌🌺

I've recently found and fixed a bug in my ESP32C3 based ducted HVAC WiFi add-on for my daikin system, so I wrote up a long overdue blog...

I've recently found and fixed a bug in my ESP32C3 based ducted HVAC WiFi add-on for my daikin system, so I wrote up a long overdue blog post about it.

Pretty fun project covering; home assistant, esphome, a custom low-level C++ binary driver, custom circuit boards and a 3d printed enclosure, now all hidden away in a drywall cavity.

https://gregdavill.com/posts/daikin-esp-001/

First board designed and assembled to test out new RP2350 silicon samples.Planning on testing out data-rates between PIO and QSPI PSRAM,...

First board designed and assembled to test out new RP2350 silicon samples.

Planning on testing out data-rates between PIO and QSPI PSRAM, have some ideas if the rates are quick enough. (MIPI/thermal sensors/RGB sensors) 🤔
Hoping to test out 3v3 and 1v8 I/O too

Solderpaste ✨

Solderpaste ✨

Spun up a design to interface to some thermal sensors I've had on my desk for awhile. This provides power and routes the somewhat...

Spun up a design to interface to some thermal sensors I've had on my desk for awhile. This provides power and routes the somewhat strange 3-bit data bus into a syzygy interface.

Solderpaste ✨

Solderpaste ✨