Reduce RAM usage

[pierluigizagaria]

Thank you for providing this lib to the community.
I'm trying to use this library into a RC remote controller that uses lua script.
It complains for the RAM usage.

Is there any way to reduce RAM usage?

[pgundlach]

I have no idea how to reduce RAM usage. I use this library on a laptop with plenty RAM so I have never had the need to look at that.

[pierluigizagaria]

The big arrays are the one that occupies ram.
Could you simplify the qr code generation by removing advanced options? Or maybe by removing the big declared tables?

[pgundlach]

How much size do the arrays take? I assume that the cclxvi table takes up most space and can be calculated on the fly. The other tables? I am not really sure how to calculate those.

[alufers]

FYI: I've done the optimization and created an EdgeTX script based on this lib: https://github.com/alufers/edgetx-gps-qrcode

Here are is the outline of the modifications I had to make to make it run on the STM32 embedded in my radio: https://github.com/alufers/edgetx-gps-qrcode/blob/master/gps_qr.src.lua#L9

TL;DR: I had to remove almost everything not used for generating a binary QR code with the L error correction, and code-golf it to minimize the RAM usage. Additionally I run the script through a minifier.

The modifications remove useful features, so I would not want to contribute them here.