DDS Module

Bpod direct digital synthesizer (DDS) module, Designed by Sanworks.

The DDS module outputs a continuous sine or triangle wave, with frequency and amplitude modulated by the state machine, a separate Bpod module or both in parallel.

Specs:

• • Arduino-compatible 96MHz ARM Cortex M4 processor (Teensy 3.2)

  • Direct digital synthesis IC (DDS) - AD9834.

    • Driven by 10MHz oscillator, anticipating output frequencies between 1 and 100kHz

  • 12 bit digital amplitude control with an external DAC IC: AD5620

    • Output amplitude from 150mV to 650mV peak-to-peak

  • 1 Bpod state machine port.

  • 1 Bpod module port (most often used for streaming digital inputs, with configurable mapping to frequency outputs).

  • BNC output connector

  • Module can optionally derive its power supply from pocket state machine (using an on-board jumper).

Note: This module loosely implements Analog Devices Circuit Note CN0156 for amplitude control. The output channel is directly driven by the DDS IC, resulting in a DC offset that varies slightly with the amplitude setting. See the amplitude adjustment section in the MATLAB plugin documentation for more info.

Firmware for the DDS module is available here.