• Sinusoid generation

    Nathan Petersen10/08/2018 at 14:51 0 comments

    PolySynth comes to life! We can finally generate simple sinusoidal waveforms out of the DAC at arbitrary frequency!

    Channel 0 above pulses once per period, so the frequency of that pulse indicates the sine waves' frequency. The above example shows a ~1 kHz sine wave output. The lines DIN, CLK, and CS are the serial interface from the MCU to the DAC. They are toggling much faster than 1kHz (approximately 1 MHz).

    To do this, we store sine wave samples in a lookup table and simply iterate through them, streaming them out over SPI at a set frequency.

    Now that the hardware drivers are in place, all that is left is to build a firmware stack on top of this to generate multiple frequencies via Additive Sinusoidal Synthesis.

  • PolySynth PCB assembled!

    Nathan Petersen09/25/2018 at 19:52 0 comments

    I know not much time has passed since my previous post, but I have the PolySynth boards assembled!!!

    They look very nice :) I didn't have any footprint issues; everything is going to plan.

    Next step is to develop firmware to do the Additive Fourier Synthesis ...updates to follow.

  • Boards have arrived!

    Nathan Petersen09/25/2018 at 19:39 0 comments

    After weeks of waiting, boards have arrived from Seeed Studio! Look good! :)

    I will get them assembled and post when I start testing. Should be very soon.

  • Ordered first boards!

    Nathan Petersen08/29/2018 at 15:36 0 comments

    As of 8/23/2018, PolySynth boards have been ordered! I got 10 from SeeedStudio for cheap, so hopefully they will be of good quality... I've never had a problem before with Seeed, so let's hope they continue to work well for me.

    Since this project log update is a few days delayed, the boards should arrive soon! I'll let everyone know when they arrive and I get them assembled.

    Metal layers from PCB order
    Top and bottom layers of just the metal areas (no pours).