Objective
This example project uses the ADC in the PIC32 to convert a voltage from analog to digital and display the magnitude of the result on the four LEDs found on the Digilent® chipKIT® WF32 development board.
The MPLAB® Harmony ADC Driver and Peripheral Libraries are used to achieve this. The MPLAB Harmony Configurator (MHC) is used to configure the ADC Driver to generate an interrupt after acquiring and converting sixteen samples. The Interrupt Service Routine (ISR) calls a function to read and average the results from the ADC results buffer. It also sets the dataReady flag, indicating it's time to update the LEDs with the new ADC result.
The code you will add to this example project (as described in the following steps) implements the state machine shown in the diagram below:
The Project and Source Files download (see below) contains a fully functional project. It can be used as an example and requires no modifications. To gain a deeper understanding of how to use the MPLAB Harmony framework, we recommend generating the project and source files yourself by following the step-by-step procedure below.
Materials
Hardware Tools
| Tool | About | Purchase |
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 chipKIT™ WF32
Development Board |
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 chipKITTM PGM
Programmer/Debugger |
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Software Tools
This project has been verified to work with the following versions of software tools: MPLAB X IDE v3.25, MPLAB XC32 Compiler v1.40, MPLAB Harmony v1.07.01.
As the tools are regularly updated, there may be occasional issues while using newer versions. If that is the case, we recommend using the same version as specified in the project.
The archived versions of our tools can be found below:
MPLAB Harmony
MPLAB X IDE and XC32 Compiler
Note that multiple versions of all these tools can co-exist on the same computer.
| Tool | About | Installers |
Installation
Instructions |
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| Windows | Linux | Mac OSX | |||
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MPLAB® X
Integrated Development Environment |
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MPLAB® XC32
C/C++ Compiler |
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MPLAB® Harmony 1.xx
Integrated Software Framework |
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Exercise Files
The contents of the following ZIP file need to be placed in this directory. If this is not done, the MPLAB X IDE will not be able to find all source files and the project will not build successfully.
<Harmony install path>/apps/training
(example Harmony install path = c:/microchip/harmony/v1_07_01)
| File | Download |
Installation
Instructions |
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| Windows | Linux | Mac OSX | ||
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Project and Source Files
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Procedure
The Project and Source Files download provides a fully functional project. It can be used as an example and requires no modifications. Below are the step-by-step instructions on how the project was created:
1
Create a new MPLAB Harmony project
The Target Device used on the chipKIT WF32 is the PIC32MX695F512L.
in the toolbar).
2
Use the BSP to load appropriate default values for the PIC32 core, clocks, and I/O port pins.
3
Use MHC to enable and configure the ADC Driver
4
Use MHC to generate the code
5
Add application states and variables to your project in app.h
6
Add application-specific configuration constants to the project in system_config.h.
7
Add code to the ADC Interrupt Service Routine.
8
Create the callback function called by the ADC Interrupt Service Routine.
9
Create the function to display the ADC average on the LEDs.
10
Create the application initialization function.
11
Create the APP_Tasks() function to implement the application's state machine.
12
Connect the development board and programmer/debugger to your computer, then select the XC32 compiler version and programmer/debugger for the project
13
to Results
After successfully programming the device, at least one LED will turn on. Turning the POT all the way to the left will light a single LED. As you turn the POT to the right, more LEDs will turn on (similar to a volume indicator).
Conclusions
This example project demonstrates much more than configuring, monitoring, and controlling PIC32 ADC. You've also learned the basic program architecture common to all MPLAB Harmony projects.
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