ESP32 support?

[vr6syncro]

Hey is there a way to support ESP32? or can we add a ESP32 as a handle between Webinterface and Bluetooth? I wanna docker that webui and send it via wlan. The ESP32 have Bluetooth to communicate with the printer.

Any idea? I haven't delved deeper into the program code yet

[NaitLee]

ESP32 is embeddable thingy, so this Python codebase won’t work, and it needs dedicated code to hook to the web interface.

Anyway, that doesn’t mean it’s difficult. I have a spare ESP32 to investigate with, hopefully I can come up with a solution in the future. (I can do C and I have some experience with this stuff)

If you are experienced in these embeddable things and going to make a solution — I’m working on a new web interface, so you may come up with a new communication interface.

Be aware that an ESP32 could do MUCH more by itself than using web interface, e.g. piping stuffs, embedding fonts, etc… so don’t limit yourself to just web :) existing hacks with the python cli could give you inspiration :)

[vr6syncro]

Hey, the esp just need to be a middleman wifi to Bluetooth. So i think that should be easy because it is all existing we need only to Split the file that send data over bt and let the esp do it and add the middlemen software

[NaitLee]

The current web frontend only produces image data, it’s the python backend produces bluetooth traffic.

The backend could dump its traffic. (without really connecting to printer, i.e. fake run)

Example command:

echo 'Hello, world!' | python printer.py -f GB02 -m -t 1,unicode,pf2 -

would produce a traffic.dump, as well as dump.pbm for the printed image. (you need a pf2 font bundle placed in cat-printer root dir for this command to run)

Though, in order to cleanly split the data, the dump format should change a bit, to include length of a “piece” in a leading byte. (it’s a whole binary chunk, while we should only send complete command “pieces” to printer)

Let me see if I can make some prototype ESP32 code in the following days :)

[vr6syncro]

Thanks, i will Look into the Code aswell when i have more time

[NaitLee]

Just now roughly modified this piece of code to work with cat printers to print some fixed data.

Stuffs attached are code and compiled firmware to let an ESP32 scan & connect to a cat printer, print embedded “Hello, world!” bitmap & traffic data and stay there. Log is available via ttyUSB in baudrate 115200.

Flash with this command:

python3 esptool.py write_flash --flash_mode dio --flash_freq 40m --flash_size keep 0x1000 bootloader.bin 0x10000 firmware.bin 0x8000 partitions.bin

I’m personally using PlatformIO and IDF framework. The firmware is created using a preset config called “esp32thing” though I guess it’s generic. (My chip is ESP32-D0WD-V3 (revision v3.0))

I’m not professional and please point out anything wrong 🤣

cat-printer-esp32-hello-world.tar.gz

[NaitLee]

There’s already a library that seemingly supports cat printers on embeddable chips: https://github.com/bitbank2/Thermal_Printer

[vr6syncro]

hey, i installed the Thermal_Printer libary but had to modify it to work with MX06 printer. But i want a webinterface or connection to my smarthome.. the it seems i must program this by myself.