Tone Discriminator Evolved on iCE40 FPGA

Data created by an experiment that evolved a tone discriminator on an iCE40 FPGA. The experiment was originally conducted by Adrian Thompson on an Xilinx XC6200 FPGA in 1997. This is the reproduction on a modern FPGA.

The tone discriminator is a circuit on the FPGA that creates a 3.3 V output signal if presented with a 10 kHz square wave input and a 0 V output signal for a 1 kHz input signal. The circuit was evolved with a Genetic Algorithm and evaluated in three ways:

1. Clamping: Iterative process to evaluate which cells in the circuit contribute dynamically to the output. A random cell is chosen a and its output set to a random constant value. Afterwards the fitness of the circuit is measured. If it decreases by less than 1 %, the cell is kept clamped, else reset to its original state.
2. Temperature dependence: The FPGA with the circuit was cooled or heated to different temperatures and presented with different input frequencies. The output was averaged over 5 s.
3. Location dependence: The circuit was moved to a different location o the FPGA. The Genetic Algorithm was then continued for additional 200 generations.

This upload contains four groups of files:

1. experiment.h5
   • All measurements and chromosomes from the original run of the Genetic Algorithm
2. clamping.h5
   • All measurements of the clamping process
3. temperature-XX.h5
   • All measurements for a different temperature
   • XX is the temperature in degree Celsius
4. new_location-X.h5
   • All measurements and chromosomes for the continued Genetic Algorithm at a new location on the FPGA
   • X is the running number for hundred generations in the file, e.g. 2 contains generations 101 to 200

Errata:

• The timestamps for the temperature measurements are missing in all files but experiment.h5.