freeDSP Classic SMD B - DIY

The freeDSP Classic SMD B is a programmable signal processing board for audio signals. It is equipped with an ADAU 1701 DSP from analog devices

This offer includes a partially assembled PCB, only the THT Parts need to be soldered by yourself. The board has been developed by the freeDSP project, you can find further information regarding the project and this board at freedsp.cc

The signal processor is programmed via a graphical programming interface running on a standard PC, therefore no special knowledge regarding DSPs is required. With dimensions of only 100x80mm the board is very compact in size and can be integrated in different applications.

The software tool used for programming is Sigma Studio from analog devices. This software allows configuring customized algorithms from pre-defined functional blocks by drag and drop. No specific high level programming skills are required. In addition to that the tool enables the run time adjustment of parameters so the algorithms can be optimized quickly and without compiling and downloading the code after every change in the programm. The software is only available for Windows OS, for programming the board, a special adapter like the freeUSBi which can be obtained in this shop is required. Alternatively programming with an arduino board is also possible.

The freeDSP classic SMD B is not only a break-out-board for the ADAU 1701 DSP to provide easier access to the pins. It is a complete DSP unit that can be operated without additional parts and includes the following submodules / functionalities

• Large input voltage range from 5-27V DC enabled by a high efficiency switching converter
• Muting circuit for supression of noise during startup
• Selectable input sensitivity from three levels by on-board jumpers
• 2 inputs and 4 outputs with RCA connectors
• Active output filters
• Onboard EEPROM for stand alone operation without a PC
• 4 extension ports with digital sound interface (I2S) for connection of peripherals like digital interfaces or amplifiers
• Termination resistors in the output channels to prevent unwanted reflections

In addition the freeDSP project indicates the following figures to be typical for this board

• Sampling rate 44.1 kHz / 48 kHz
• Bit depth 24 bit (DSP uses 28bit single und 56 bit double precision internally)
• Input level 0,9 – 2V (selectable)
• Input impedance 7.5 kOhm (max 0.9V) up to 13.9 kOhm (max. 2V)
• Output level 0,9V (2.5Vpp)
• Output impedance 336 Ohm
• Dynamic range 98 dB
• Harmonic distorsions THD -73 dB bei 1kHz, -10 dBV
• Power consumption <0,5W up to 12V DC, <0,6W up to 25V DC
• System clock 24,576 MHz
• Footprint 100x80 mm