This page will document all the changes for the second revision of solar sense → changes found from validation and assembly:
- relay footprint is wrong → increase the through hole size, pad size and distance between everything so it actually mates
- have a pin on the controller board get a high or low if connected to the right jumper config for 5 vs 6 mppt board
- none of the vias tented?? maybe manufacturing issue (this was not jlc) but double check pcb
- move C32 north so 12V isnt shorted to ground 😞
- switch mosi and clock and fix miso silk (says mso)
- reconfigure relay driver for low side output for current sinking IC
- indicator LED for 12V
- move the I2C pullup resistors to be near the controller board, not near the first mppt
- Add a fan control IC for solar fan (meant to help cool nomuras inside enclosure) controlled by onboard thermistor (from 5 mppt board extra thermistor slot) and powered off of solar (will be depopped for 6 mppt solar board)
- Also reconfigure thermistors so that the on-board resistor is a pull-up resistor and calculate the correct pull-up resistor values for the 2 types of temperature sensors - 100Ohm platinum RTD and 10K NTC thermistors
- Add more clearance to power pads from GND pour (this may have helped the C32 12V short to gnd, its weird it did not give me a warning about that…)
- Add LEDs for all the rails
- The relay driver has a status pin that turns on an LED when operational, however I forgot to connect that line to the relay sense pin on PA6 that is input to the controller board. Either use that status pin for relay sense, or an additional sense circuit on the contacts for that input. Rev 1 has absolutely no relay sense.