First, 90 percent of your "thanks" has to go to the zxing dev team of the original java based project. :)
Now your question. Some weeks ago I "ported" ZXing.Net to the .Net Micro Framework which is the base of such small devices.
BUT I don't have such a device. I can't make real world test. I run only a small example within the emulator.
It works, that means you can compile the project, you can run it and you will get results! But the emulator is very slow.
There are some places where the .NetMF port of ZXing.Net can be optimized for small devices.
I have no idea if the CPU and memory is enough for a good decoding experience.
It would be great if you can test it and post your results here. I will help you if you have trouble with the source code.