OpenSprinkler-Firmware for 4 Channels Relay Boards with ESP-12F

This Firmware is a slightly modified variant of the original OpenSprinkler firmware to run with an inexpensive 4 Channels Relay Module AC/DC ESP-12F Development Board (a.k.a. "ESP12F_Relay_X4")

See also ESP12F_Relay_X4_Schema.pdf

Supported Features:

• 4 OpenSprinkler station, controlled by the board relays
• 3 Buttons
• OLED Display (SSD1306, 128x64)

Known Restrictions

• Only 4 sprinkler stations are supported (no support for Zone Expander)
• Sensor 1 and 2 are not supported yet (GPIO1 and GPIO3 could be used)
• RF Transmitter not supported yet (GPIO10 could be used)
• Current sensing is not supported (disabled on the OLED display)

Used Hardware

• ESP12F_Relay_X4 board

  • Solder all supplied pin headers
  • Attach the relay jumper
    • RY1 <—> IO16
    • RY2 <—> IO14
    • RY3 <—> IO12
    • RY4 <—> IO13

• 128x64 OLED Display (SSD1306)

  • Wiring: Display <—> ESP12F_Relay_X4:
    • GND <—> GND
    • VCC <—> 3.3V
    • SCL <—> IO5
    • SDA <—> IO4

• Real Time Clock (DS1307)
  Since this is a 5V module it's important to remove the pull up resistors (5V!) on SDA and SCL.
  
  It's also important to use a rechargeable battery LIR2332!

  • Wiring: RTC <—> ESP12F_Relay_X4:
    • GND <—> GND
    • VCC <—> 5V
    • SCL <—> IO5
    • SDA <—> IO4

• Push Buttons

  • Wiring: ESP12F_Relay_X4 <—> Button <—> Powering:
    • IO2 <—> Button 1 <—> GND
    • IO0 <—> Button 2 <—> GND (IO0 has an external pull up resistor on the board!)
    • IO15 <—> Button 3 <—> 3.3V (IO15 has an external pull down resistor on the board!)

• USB to TTL Serial Adapter 3.3V

  • Assure that the Adapter is set to 3.3V (in case it supports also 5V)
  • Wiring: TTL-Adapter <—> ESP12F_Relay_X4 (only needed during programming):
    • GND <—> GND
    • RXD <—> TXD
    • TXD <—> RXD
    • 3.3V <—> 3.3V

• Valve Power Supply (e.g. 24V~Bell-Transformer, in case you use 24V AC valves.)
  Important: If you want to turn on the transformer via a relay (as OpenSprinkler Master Zone) you should consider to use a "RC Circuit" aka "Snubber" to protect the relay contacts.
  

• Enclosure (e.g. TRU COMPONENTS TC-9065652 Universal enclosure, in case you want to place the transformator into the enclosure)

Used Software

• Visual Studio Code
• PlatformIO IDE Extension

Building and flashing of the firmware

• In PlatformIO select the "esp12f_4ch_relay_board" task of the Project
• Build the firmware
• To activate the Flash-Mode Press and hold Button 2 until the reset button on the ESP12F_Relay_X4 board was also pressed
• Upload the Firmware
• Press the RST button of the ESP12F_Relay_X4 board
• Follow the instructions of the OpenSprinkler User Manual

Meta

Distributed under the GNU General Public License license. See LICENSE.txt for more information.

https://github.com/ThFischer/OpenSprinkler-Firmware/tree/ESP-12F-4CH-Relay-Board

Update:

Since the WiFi connectitivity was quite poor I added an external antenna. See https://www.instructables.com/External-Antenna-for-ESP8266/ for more details.

Another variant …

I added the branch "NODEMCU_74HC595" branch that uses a NodeMCU, 74HC595 ShiftRegister and an 8Ch 5V Relay board.