- Codec2 Low Bit Rate Speech Codec. A low bit rate, communications quality speech codec that fills the gap in open source speech coding at 2400 bits/s and below. Applications include digital speech over HF/VHF radio and extremely low bandwidth VOIP trunking.
- FDMDV Modem. A 1400 bit/s modem for Digital Voice over HF radio. The FDMDV modem is optimised for digital speech, in particular fast sync, no multi-second training sequences, the ability to recover quickly after a fade. It is implemented in both GNU Octave (for simulation and development) and C (for real time operation).
- FreeDV. A GUI Application that bundles the Codec 2 and the FDMDV modem projects above into an end user application for digital voice over SSB radio.
Completed (or sleeping) Projects
- The $10 ATA is a low cost, open hardware, FXS port design. It uses an Atmel micro-controller to implement both audio I/O and a DC-DC converter for telephony battery and ring voltages. It can be assembled from easy to find analog parts or even e-waste. It is being developed to lower the production cost of the Mesh Potato, and can also be used to turn any OpenWRT router into a mesh telephony device.
- The IP0X range of embedded, open hardware, open software IP-PBXes. Closely related projects include the BAPs Build System and the Mini Asterisk GUI. The Open Hardware page lists related open hardware telephony projects. In future I would like to do more work on the GUI, and try to make Asterisk as easy to set up as a Wifi router.
- Dili Village Telco: In 2010 and 2011 Rowetel and Fongtil built the Dili Village Telco, a 60 node mesh telephony network in Dili, Timor Leste. This project was kindly sponsored by ISIF and ISOC grants.
- The Mesh Potato: The Mesh Potato is a 802.11bg mesh router with a single FXS port. It is custom hardware designed to give people in the developing world affordable telephones. Adjacent mesh potatoes automatically form a peer-peer network, relaying telephone calls without land lines or cell phone towers. The Mesh Potato is designed using open hardware and software and is part of the Village Telco project. Lots of blog posts and progress updates on the Village Telco blog. The Shuttleworth Foundation kindly sponsored this project. The Mesh Potato entered production in September 2010. Lots more information on my Village Telco and Mesh Potato work here.
- Open Source Line Echo Canceller: A very popular high quality line echo canceller for Asterisk that is free (as in speech). Works with any Zaptel and DAHDI compatible hardware, from humble X100Ps to multiple PRIs. Removes the need for expensive “hardware” echo cancellation. Part of many Asterisk and Linux distributions and now part of the Linux Kernel!
- Electric Car: I drive an electric car every day. My EV has a range of 100 km, 120 km/hr top speed, and runs on 120V at 450A peak. I rarely use my other, internal combustion car any more, and can’t remember the last time I bought petrol! Lots more information on my EV page.
- Lowering my home energy consumption: At my previous home I enjoyed an ongoing project to slash my energy bills and make the home independent of fossil fuels. Over a two year period I slashed electricity consumption by 70%, consumed very little natural gas, and almost no petrol. Our house was more comfortable. We saved thousands of tax free dollars on car maintenance and fuel and had near-zero energy bills. We used the money saved to work on projects that interest us and help people, rather than working for money to pay ever increasing bills. Lots of posts in the Renewables and Electric Vehicles blog categories.