Here is a new version of our backplane, taking into account all our recent design changes. Clearly, we don’t have much room left for any additional component, which is a good things, because it will prevent us from adding new features.
Within every submodule section, we have 20 pins on the left and another 40 pins on the right. The left connector is used for the 16 analog ports, a reference level, 12V power supply, 5V power supply, and ground. For its part, the right connector is used for the 16 inputs and 16 outputs that are connected to the digital potentiometers, the 4 wires of the SPI bus, 1 GPIO connected to the Pi, 1 ground, and 2 pins left for future use.