QR code generate in microcontroller

[Vindhyachal.takniki]

1. I have to generate QR code, have string of 100 bytes which needs to be fit in.
Controller I am using is Atmega2560 arduino.
generated code is to be shown on TFT & to be print on thermal printer also.

2. There are few libs on it in C/C++, but all use malloc functions. Is there any simple to use library for this? Any one has worked on it before?

[hamster_nz]

I've used another 2D bar code, PFD417 ( https://en.wikipedia.org/wiki/PDF417 ) on an STM32 controller to display on an LCD. It worked well, and I feel is better suited to lower quality printers than QR codes.

On a PC I started with https://sourceforge.net/projects/pdf417lib/, and then manually replaced all the unchanging variables (width, height, barcode parameters like ECC) with constants, and rather than generating objects (aka malloc()ing a a structure, populating it, and then returning it's address to the caller) I had just one structure statically allocated. Along the way I generated BMP files and tested reading it with a free PDF417 reader app (https://play.google.com/store/apps/details?id=mobi.pdf417&hl=en) on my phone to make sure I hadn't broken it.

Once that was all done and debugged on the PC, then moved it to the STM32 and LCD with zero problems or embedded debugging required.

[Jeroen3]

The mostly use malloc because the input is variable length.
You can probably implement malloc, and make it just return one fixed memory block.

Have you searched github yet? I did find some C libs in a quick search. Maybe it's something.
https://github.com/fukuchi/libqrencode
https://github.com/tz1/qrduino
https://github.com/embedded-systems/qr

[amyk]

Figure out the size of QR code that you'll need, then replace all malloc()s with the appropriate constant-size array.

(A lot of code out there needlessly uses malloc() in general, even for constant sizes.)