HC12 Setup Tool

HC12 modules are 433Mhz band wireless serial modules. These modues are set up using a set of AT commands. This project is a very hasily hacked together tool to make it easy to configure one of these little do-hickies.

Instructions

• Wire your ESP8266 to your HC12 according to the pinout defined in the Config.h file
  • HC12_RX connects to the TX pin of the HC12
  • HC12_TX connects to the RX pin of the HC12
  • HC12_SET connects to the SET pin of the HC12 (pin 5)
• Also connect 3.3v power to the HC12/VIN and GND to GND
• Build and upload the sketch to your microcontroller
• Connect a serial terminal to your microcontroller, running at 115200 baud
  • If you use the Arduino IDE Serial Monitor, set line ending to newline.
• Reset the microcontroller
• You'll should see the baud menu
  • Choose the baud rate for your HC12 unit
  • The default is 9600 bps, which is how they come from the factory
• At the main command prompt, use h for help
• Type in commands (e.g. AT+RX), press return to execute command
• Reset your microcontroller to choose a different HC12 baud rate

Note

This sketch uses SoftwareSerial for communications with the HC12. I recommend using a fastish microcontroller with this sketch (I use a NodeMCU / ESP8266). Older Arduinos like unos and nanos might be less reliable with the SoftwareSerial if the speed goes much above 9600. Might still work though. :)

Pre-requisites

• Install the Arduino IDE 1.6.6 or later
  • Windows & Mac users may find a download link here
  • Major Linux distros carry it in their software repositories, or the link above may be used
• In the Arduino IDE, install ESP8266 board support from Tools -> Board -> Boards Manager
• In the Arduino IDE, install ESP8266 tools from Sketch -> Include Library -> Manage Libraries

Building Using the Arduino IDE

This method is preferred on Windows and for casual users who just want to build and use the project.

• Open Arduino IDE
• Open firmware/firmware.ino
• Set the board you are using (under the Tools -> Board menu)
• Connect board with USB cable
• Click the Upload button on the tool bar

Using make on Linux

This alternative build system may also be used. It is an alternative to using the Arduino IDE and may be preferred by some users.

• Install the esp/Arduino Makefile
• Edit the esp.mk file and set the include line to point at where you installed makeEspArduino.mk (or set the ESP_MAKEFILE environment variable)
• Edit firmware/Makefile and uncomment a BOARD for the board you're using (to see a list of possible boards, run make list_boards from the firmware directory)
• Connect your ESP board with a USB cable
• Press and hold the flash button on the board and use the command make flash from the firmware directory