1.3 ADC User Sequence
This example application shows how to sample three analog inputs using the user sequencer in software trigger mode and send the converted data to the console.
Description
Conversion of the three analog inputs is triggered from software trigger at every 500 ms. The user sequencer is used to define the order of conversion:
| Board | Sequence of conversion |
|---|---|
| SAMA5D29 Curiosity Development Board Kit | AD5 –> AD6 –> AD7 |
Analog input voltage in the range of 0V to 3.3V is fed to the ADC input channel AD5, AD6 and AD7. ADC conversion result is displayed on the console.
Downloading and Building the Application
To clone or download this application from Github, go to the main page of this repository and then click Clone button to clone this repository or download as zip file. This content can also be downloaded using content manager by following these instructions.
Path of the application within the repository is apps/adc/adc_user_sequence/firmware.
To build the application, refer to the following table and open the project using its IDE.
| Project Name | Description |
|---|---|
| sam_a5d29_curiosity.X | MPLABX project for SAMA5D29 Curiosity Development Board Kit |
Setting Up AT91Bootstrap Loader
To load the application binary onto the target device, we need to use at91bootstrap loader. Refer to the at91bootstrap loader documentation for details on how to configure, build and run bootstrap loader project and use it to bootstrap the application binaries.
Setting Up the Hardware
The following table shows the target hardware for the application projects.
| Project Name | Description |
|---|---|
| sam_a5d29_curiosity.X | SAMA5D29 Curiosity Development Board Kit |
Setting Up SAMA5D29 Curiosity Development Board
- Connect the UART Debug port (J28) on the board to the computer using a FTDI USB to serial cable.
- Connect the Debug USB port on the board to the computer using a Type-C USB cable (to power the board)
- Use a jumper wire to connect Pin 37 of J25 (AD5 is mapped to Port Pin PD24) to 3.3 V or GND
- Use a jumper wire to connect Pin 1 of mikroBUS1 J19 (AD6 is mapped to Port Pin PD25) to 3.3 V or GND
- Use a jumper wire to connect Pin 1 of mikroBUS2 J22 (AD7 is mapped to Port Pin PD26) to 3.3 V or GND
Running the Application
- Build the application using its IDE
- Open the Terminal application (Ex.:Tera term) on the computer.
- Connect to the Virtual COM port
and configure the serial settings as follows:
- Baud : 115200
- Data : 8 Bits
- Parity : None
- Stop : 1 Bit
- Flow Control : None
- The console displays the ADC Count and the ADC Input Voltage
