Testing the FXS Interface

FXS Interface PCB design

FXS Interface PCB design

In electronic hardware design you can be sure that anything new and untested will have bugs. So I have a habit of building the new part and testing it using known working hardware. The engineering concept is to test and debug the absolute minimum, as bug counts tend to increase exponentially with complexity.

With the Mesh Potato the FXS Interface hardware is new. This design connects the router to an analog telephone. So Elektra and I have designed a small PCB to test just that part of the design. Here are some pictures of (i) the small FXS interface PCB design we have designed and (ii) an assembled FXS interface PCB, with a WRT54 for scale.

The idea is to connect this PCB to a Nanostation 2 or DIR-300 router and build up the Mesh Potato FXS functionality. We can then incorporate any bug fixes into the Mesh Potato prototype.

This strategy is also a time saver – while Atcom are laying out and building the PCB for the Mesh Potato Prototype, we can be using the FXS interface hardware above to develop the Mesh Potato software. That way we reduce the overall length of the project as when the Mesh Potato Prototype arrives we will have tested and debugged firmware to run on it.

We have plenty of spare PCBs so if any one would like to build up a FXS interface please let me know.

Assembled FXS Interface

Assembled FXS Interface

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3 Responses to «Testing the FXS Interface»


  1. April 27, 2009 at 11:36 pm, Beer, Coffee, and a little DSP » Blog Archive » Mesh Potato FXS Interface said:
    [...] have just blogged on the Mesh Potato FXS Interface over on the Village Telco [...]

  2. May 11, 2009 at 5:06 am, Carlos Eugenio Martínez Cruz said:
    I have interest in having some PCBs. If you still have some to spare send them to Carlos Eugenio Martínez Cruz Apartado Postal 05-191 Metrocentro, San Salvador El Salvador

    • May 11, 2009 at 9:02 am, Steve said:
      Hi Carlos, If you send David Rowe a message via his blog http://rowetel.com/blog, he may be able to help you out.

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