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Network PDU-S: RevA Complete!

Here it is!

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Postmortem

The final product turned out pretty great.  I’m glad I followed through and turned RevA into a fully functional product despite the constant desire to redesign every time I ran into issues.

  • Silkscreen text too small.
  • Instead of 22uf Ceremic caps switch to 47uf electrolytic for cost savings
  • Shink size of SOIC pads so they get less solder
  • Use 4mil stencil
  • Add stencil alignment tooling holes to board and stencil 
  • Reduce BOM.  Since I’m used to working on high performance RF devices I tend to use too many bypass caps for such a low speed design.
  • Use smaller microcontroller.  The ATMeega2560 was too large physically, feature wise, and cost wise.
  • Use smaller vias
  • Figure out how to use interrupts with wiznet to cut down polling
  • Reduce board size.
    • Switch to using 2 boards: 1 for relays+ drivers, and the other for the main circuitry.
    • This will allow changing the relay board for some NEC UB2-12NJ relays if I want to do a low-voltage version.
    • This will allow the main RJ45 jack to butt up to the back panel.
  • Add the Wiznet reset line to avr so I can reset manually if watchhdog timer fails.
  • Test points!
  • Bottom size copper keepout around relays to avoid arcing
  • Add an LED per relay.
  • Add power monitoring per outlet
  • Finish zero crossing detector to improve relay lifetime.
  • Switch the Power button LED to a port with PWM output so I can do the “breathing” LED effect.
  • Make the power-monitoring module an addon (CT, Zero crossing, Vsense)
  • Mirror RJ45 differential termination so they stay coupled better.
  • Enclosure cutout for the IDC power inlet was the wrong size.  Had to file it down a bit.
  • Need a rear on/off switch with integrated 15A breaker for power cycling the logic.

One thought on “Network PDU-S: RevA Complete!

  1. Hi,
    You did so great job!

    I am from WIZnet (I already contacted you through Hackaday contact form)
    If you have had any problem in using our chip, just tell us any time!

    Also, if you have any plan to develop a project that network solution is required, we can recommend any good solution.

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