The RiffPod Story

RiffPod idea

Inspiration can strike in a moment. And when it happens, you want to capture it. In that moment. You think of a tune, you strum it on your guitar, you should be able to record it. No wires, no mic stands, no mixers, no complicated setup. It should be that easy. I wanted it to be.

Imagining so, I backed a Kickstarter project called Acoustic Stream. It promised Bluetooth streaming from my guitar to my smartphone. It failed miserably. The final update is a classic (Ready to Ship!):

Our original project concept turned out to have some technical challenges related to wireless streaming of sound via Bluetooth as well as some limitations in the iOS codec (the algorithm for sound processing that Apple uses) that prohibited us from achieving our goals related to wireless recording and playing.

Now I know that some of our backers were excited about the wireless capabilities of the product. But as with many aggressive Kickstarter technology projects, sometimes the vision exceeds the currently available technology. So we had to make the hard decision to pull those features. We’re sitting on some cool technology, but it would have been a bad experience if we had kept it in.

I was back to square one, only $150 shorter. I decided to do something about it. I found two kindred souls (Nikhil and Jonny) who have the technical chops and believe in the concept of RiffPod.

The basic idea is simple — acquire the sound channel from a guitar’s pickup and transmit it via WiFi. An accompanying app can be then used to record the sound stream on a smart device. The same app can be used to control the device (monitor, start, stop, set channel gains, etc.).

RiffPod streams 2-channel sound via WiFi. Main features:

  • High fidelity recording: 16-bit, 44.1kHz
  • Wireless: comes up as a WiFi access point
  • Works with smartphones and tablets
  • Pass-through for feedback (headphone out)
  • Second channel to stream an accompanying vocalist or instrument

Current Status

We have a fully functional prototype including hardware, firmware, iOS and Android apps.

Device firmware. RiffPod access point (AP) listens for start and stop commands. When the start command is received, it begins to acquire the sound signal and streams it, and stops when the stop command is received. Todo: dynamically change channel gain upon demand, store and retrieve the gain values from flash memory.

iOS app. Sends start and stop commands to control streaming and records the stream. It shows a visualization of the sound stream using charts. It allows playback of the recording. It allows sharing of the recording with third-party apps. Todo: make RiffPod compatible with Digital Audio Workstations (DAWs) such as Garageband.

iOS Screenshot

Android app. Sends start and stop commands to control streaming and records. It shows a visualization of the sound stream using charts. It allows playback of the recording. Todo: integration with Audio Evolution, stability improvements

Android Screenshot

Hardware. All development was done on development boards from Texas Instruments. Todo: Integrated PCB prototype validation, enclosure design and prototype, battery life testing.

RiffPod PCB