OpenTAC sprint, Cambridge

Last weekend saw a small group get togeather in Cambridge to hack on the OpenTAC.  OpenTAC is an OpenHardware OpenSoftware test platform, designed specificly to aid automated testing and continious intergration.

Aimed at small / mobile / embedded targets OpenTAC v1 provides all of the  support infrastructure to drive up to 8 DUTs (Device Under Test) to your test or CI system.
Each of the 8 EUT ports provides:

  • A serial port (either RS232 levels on an DB9 socket, or 3V3 TTL on a molex kk plug)
  • USB Power (up-to 2A with a software defined fuse, and alarm limits)
  • USB data interconnect
  • Ethernet

All ports on the EUT interface are relay issolated, this means that cables to your EUT can be ‘unplugged’ under software control (we are aware of several SoC development boards that latch up if there is a serial port connected before power is applied).

Additionly there are 8 GPIO lines that can be used as switch controls to any EUT (perhaps to put a specific EUT into a programming mode, reboot it or even start it)


Anyway, back to the hacking weekend. ..


Joining Steve McIntyre and myself were Mark Brown, and Michael Grzeschik  (sorry Michael, I couldn’t find a homepage).  Mark traveled down from Scotland whilst Michael flew in from Germany for the weekend.  Gents we greatly apprecate you taking the time and expence to join us this weekend.  I should also thank my employer Toby Churchill Ltd. for allowing us to use the office to host the event.

A lot of work got done, and I beleive we have now fully tested and debugged the hardware.  We have also made great progress with the device tree and dvice drivers for the platform.  Mark got the EUT power system working as proof of concept, and has taken an OpenTAC board back with him to turn this into suitable drivers and hopfully push them up stream.  Meanwhile Michael spent his time working on the system portion of the device tree; OpenTAC’s internal power sequancing, thermal managment subsystem, and USB hub control.  Steve  got to grips with the USB serial converters (including how to read and program their internal non-volatile settings).  Finally I was able to explain hardware sequancing to everyone, and to modify boards to overcome some of my design mistakes (the biggest was by far the missing sence resistors for the EUT power managment)