At the core there is the micro controller, MCU, which is programmed to run the BlipBox interfaces and coordinate all other components. This is an AVR ATMega processor, and the program it runs is the device firmware, which we call BlipOS.
The LEDs are controlled by a TLC5940 16 channel, 12bit LED driver. The 16 channels are multiplexed across 5 rows using discrete NPN transistors.
The touch screen is a 5 wire, 5.7″ resistive screen which is controlled and read by the MCU using its 10-bit analogue to digital converters. By oversampling the conversion, a higher resolution can be achieved.
The interface board takes care of USB, MIDI and external power. For USB, a separate controller IC is required. For MIDI we use an optocoupler.
This is the first version that we produce and sell. It is characterised by its black, 4mm acrylic side panels with the BlipBox logo and name engraved on the left side. The right side houses external power, MIDI out, and USB connections.
The MCU in v9 is an ATMega168, which has been initialised with a boot loader and is compatible with the Arduino programming environment. The USB controller is an FTDI FT232RL, same as in Arduino Duemilanove and Diecimila.
BlipBox v9 can be powered over USB, or using the external power connection. External power requires a 9v, positive tip DC supply of at least 140mA. The connection is a standard 2.5mm DC plug. There is a switch between the DC and USB sockets which selects the power source. When powered over USB, the device draws less than 100mA current with all LEDs fully lit.
More recent builds are based on v10 of the PCB which is functionally identical to v9.