The implementation of a platform-independent neural network is in files nn.h and nn.c.
Data structure allocation depends on the platform. For a fixed-size network, it could be static. File nn-alloc.h declares generic functions; file nn-alloc-stdlib.c implements them using malloc and free.
The implementation can be tested with tests/xor.c, a stand-alone program which learns the exclusive-or function. The program is built by Makefile.
Neural network functions are made available to the virtual machine of Aseba and the Aseba programming language as native functions. They need support for floating-point (arithmetic operators and function tanh). Native functions are implemented in C in files thymio/nn-native.h, thymio/nn-native.c and thymio/nn-descriptions.c.
Program vmshell contains the Aseba VM, the Aseba language compiler and the neural network functions. It meakes the development and tests of the new functions easier.
In addition to the neural network functions, vmshell implements a native function test.display(a) which displays its argument:
./vmshell --code 'call test.display([1,2,345])'
To compile vmshell with the makefile, copy or create a symbolic link aseba in the directory of thymio-nn, at the same level as this README file. The content or target should be the directory aseba/aseba from https://github.com/Mobsya/aseba.