• As with anything, something that is good always can be improved. The 3.4 version builds on top of the 3.2 hardware with addition to the I/O sensors (using 2 pins from the PCA9555 I2C expander and changing DC power supply circuit. DC can now be applied from USB-C connector with PD control chip that can be controlled to deliver different voltages to the DC buck converter for controller operation and booster for controlling valves if they are wired at further distances. DC barrow connector is still available along with screw terminal for AC input. Daughter board for DC booster is still utilized for driving DC valves.
  
  Rest of the circuit remains unchanged. It still uses the PCA9555 controller for driving valves and I/O for buttons and input signals. Still uses the CH340C/G USB bridge for programming though it can be omitted to save cost as there is dedicated programming port  to utilize our USB-TTL adapter witch included the auto reset circuitry to put the ESP8266 into programming mode
  
  Like the 3.2 board, the 3.4 was designed to be used for driving either  AC or DC valves. The differentiation is in the output drive transistor. With TRIACS mounted the board is build for AC valves omitting the DC power supply section, please refer to schematic. And with NPN transistors and DC  power source and booster module it will drive DC valves.
  
  
  
  Limitation of the board is that can only be configured for AC or DC  exclusively
   

  Features

    
  
   

  Documents

     Schematic
     Gerber Files 
     Gerber Files dual
     Bill of Materials
     ESP-12 / ESP8266-12
     AP1509
     CH340G
     CH224
     AMS1117
     DS1307
     PCA9555
     24c02
     Firmware