CASP supports exchanging data between micro-controllers using LoRa communication. This example project demonstrates LoRa wireless data transmission between host PC and two remote micro-controllers using three similar nRF24L01 wireless communication modules. We try to acquire analog data from the two remote micro-controller boards to the host PC wirelessly and plot the data on the host PC. We also try to control the on-board LED and PWMs present on the target boards from the host PC. Since the nRF24L01 modules supports only SPI communication, an intermediate micro-controller is required between host PC and nRF24L01 module at the host PC end.
Pre-Requisites
- Arduino Nano, Raspberry Pi Pico, Vega Aries or any three micro-controller boards supported by CASP with SPI interface.
- nRF24L01 LoRa modules – 3 No.
- CASP software is installed along with CASP Python Libraries (optional).
- Arduino BSP is installed.
- The project files are located at CASP installed directory ‘CASP/support/examples/communication/15_lora_nrf24’. These are also available for download at this link.
Connection Diagram
Aries Vega v3.0 and Arduino Nano development boards are used as the remote micro-controller boards connected to the respective nRF24 modules. As mentioned earlier, since nRF24L01 supports only SPI communication, Raspberry Pi Pico (RPiPIco) development board is used as an intermediate micro-controller between the host PC and the third nRF24 module. These micro-controller boards can be replaced with any other micro-controller board supported by CASP and can be used in similar manner.
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 GPIO24 and PWM0 for controlling. Similarly, Arduino Nano A0,A1 and PMW pins 5 and 6 are used for data acquisition and control. Data from the host PC is transferred to RPiPico through serial communication and from RPiPico to Vega Aries and Arduino Nano through wireless communication.
CASP Model for 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 ‘nrf24_target_vega’ project. Open the workspace file ‘nrf24_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 nRF24 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.
CASP Model for 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 CASP and load the ‘nrf24_target_nano’ project. Open the workspace file ‘nrf24_target_nano.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 nRF24 block parameters.
- 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.
CASP Model for Raspberry Pi Pico 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 ‘nrf24_target_pico’ project. Open the workspace file ‘nrf24_target_pico.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 nRF24 block parameters.
- 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.
CASP Model for Host Computer
- Run another instance of CASP and load the ‘nRF24_target_native’ project. Open the workspace file ‘nRF24_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.
