LoRa Communication with Ra-02 SX1278 wireless module using CASP

This example project demonstrates LoRa wireless data transmission between host PC and a remote micro-controller using two similar Ra-02 (SX1278) wireless serial communication modules at both ends. We try to acquire analog data from the target board to the host PC wireless and plot the data on the host PC. We also try to control the on-board LED and PWM present on the target board from the host PC. Since the Ra-02 module supports only SPI communication, an intermediate micro-controller is required between host PC and Ra-02 module at the host PC end.

Target

Aries Vega v3.0 development board is used as the remote micro-controller board connected to Ra-02 module. As mentioned earlier since Ra-02 supports only SPI communication, Arduino Nano is used as the intermediate micro-controller between the host PC and the second Ra-02 module. These micro-controller boards can be replaced with any other micro-controller board supported by CASP and can be used in similar manner.

Description

Connect the circuit as shown below. Connect any sensor to the ADC pin A0 and A1 of the Vega Aries board for sensing. We use the on-board LED at pin GPIO22 and PWM0 for controlling. Data from the host PC is transferred to Arduino Nano through serial communication and from Arduino Nano to Vega Aries through the wireless communication

Following are the steps to properly program the Vega Aries board.

· Connect the target to the host PC via a USB cable.

· Note the serial port number to which the board is connected to the host PC, from the host operating system.

· Run CASP and load the ‘sx127x_target_vega’ project. Open the workspace file ‘sx127x_target_vega.wsp’ from CASP main window.

· All blocks are pre-configured for proper functioning. However, user may change the configuration of any block as required. By default data encryption is disabled user may enable the same in the SX127x block parameters.

· For Aries Vega, SPI1 is selected for SPI communication. Choose suitable SPI interface if other micro-controller targets are used.

· Open Home->Simulation->Setup Simulation Parameters menu item. Under TargetHW->General tabs set ‘Target Programmer Port’ parameter to the serial port to which the board is connected.

· Build the model and program the board by clicking on Run button.

Following are the steps to properly program the Arduino Nano board.

· Connect the target to the host PC via a USB cable.

· Note the serial port number to which the board is connected to the host PC, from the host operating system.

· Run another instance of CASP and load the ‘sx127x_target_nano’ project. Open the workspace file ‘sx127x_target_nano.wsp’ from CASP main window.

· Open Home->Simulation->Setup Simulation Parameters menu item. Under TargetHW->General tabs set ‘Target Programmer Port’ parameter to the serial port to which the board is connected.

· Build the model and program the board by clicking on Run button.

Following are the steps to run the native model on the native PC

· Run another instance of CASP and load the ‘sx127x_native’ project. Open the workspace file ‘sx127x_native.wsp’.

· From ‘Serial’ block parameters enter the serial port to which the Arduino Nano is connected to the PC.

· Click on Run button to build and run the model.

Target and Native models are shown below

Screen shot of the output simulation panel running on host PC is shown below. User can control the on-board LED on Vega Aries board by toggling the switch (sw0) in SubWindow1.

Debugging

Serial debugging can be enabled by selecting ‘Local & Remote‘ option from Setup Simulation->Build->Code Debug and re-building the project. The output can be viewed in ‘Serial Monitor’ window from CASP main window.

References

Please go through our video tutorials, tutorial projects and CASP main documentation for getting started with CASP.