The project provides the source code, schematics and PCB CAD files for the DAQ32 hardware and software. The system was originally developed as an interface to an array of up to 10 triple-axes accelerometers (Analog Devices’ ADXL335).

The DAQ32 board is a 32 Channel, 32.768 ksps, 12-bit resolution, USB data acquisition board. Input channels are multiplexed so the effective sampling rate is 32.768 ksps / (number of enabled channels); e.g. 1 channel at 32.768 ksps or 32 channels at 1024 ksps. The on-board DSP microcontroller samples at x8 for on-board filtering; e.g. 1 channel would be sampled at 262.144 ksps prior to filtering. Input signals may be between 0 V and 3.3 V or TTL. The board provides the user with a filtered power supply up to 400 mA at 3.3 V. The PCB is a 2-layer design using exclusively SMD, designed in Eagle CAD (freeware). The key hardware components are the: dsPIC33, 32.768 kHz watch crystal, FTDI USB-UART, 32 voltage-follower op-amps, 5-bit DIP switch, and power supply filtering passives. The total parts cost for one DAQ32 board is approximately £30 and may be assembled by hand. The device firmware is written in C with limited in-line assembly and requires Microchip’s MPLAB IDE (free) and C30 compiler (free version available).

The DAQ32 PC Interface software is a simple application written in C# that enables DAQ32 data to be logged to a CSV file or displayed in real-time on up to 11 on-screen, 3 channel oscilloscopes. The application makes use of Michael Bernstein's oscilloscope library with Frank Greenlee's C# wrapper. The ‘DAQ32serial.cs’ class allows the integration of the DAQ32 hardware other C# projects.

The available downloads (tab above) include: The Eagle CAD schematics and PCB design files; pre-compiled PCB Gerber files; firmware in the form of a Microchip MPLAB project folder (pre-compiled .hex included); and the Visual Studio 2008 project folder for the ‘DAQ32 PC Interface’. Additional uploads upon request; e.g. component part numbers, missing information etc.

Demonstration video:

http://www.youtube.com/watch?v=g_C-L97l_XI