Photovore

As I have stated previously, the Photovore circuit is simple in comparision to the Edgebot, therefore it has less components and required no work to make all the parts fit onto the board. Also, I could simply copy the board template over from the Edgebot files, thus causing the two boards to be identical shapes, the same header positioning and ensuring that the two boards would slot together and carry out the modular features, this also provided a starter board to use for future modules.

As you could see from the Photovore circuit in a previous post, it uses a single comparator and a inverter, however, inverters typically come in 14 pin DIP packages as the chips contain six inverters, plus power connections. Therefore I used a dual comparator and used the spare comparator as a signal inverter, thus reducing the parts to a single 8 pin DIP package.

The second revision had a simple layout change and I swapped the LDRs around, as I realised that I (for some reason) had used the principle that the higher the light intensity, the higher the resistance of the LDR, this is, however, false. So by simply swapping the LDRs around it now drives away from the darker LDR and 'into the light'.

The schematic

The PCB

The latest Photovore design files (v0.2) can be downloaded from Dropbox.