Here it is!
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.