Example Path: examples/SPI/PicKitSerialSPIDemoBd

SPI PicKit Serial Demo Board Application

Overview

This application demonstrates the use of the Microchip PicKit Serial SPI Demo Board with NetBurner embedded systems using the DSPI API. The demo communicates with seven different SPI peripheral devices through an interactive serial menu, and serves a built-in web documentation page.

API

This application uses the NetBurner DSPI API for SPI communication:

DSPIModule – SPI module instance configured per device (baud rate, chip select, clock polarity/phase)
RegisterSem() – register a semaphore signalled when a transfer completes
Start() – begin a SPI transfer with TX/RX buffers and chip-select control

Each peripheral is driven by its own DSPIModule instance because the devices run at different baud rates and clock modes.

Supported Platforms

MODM7AE70 - SAME70 based module
SBE70LC - SAME70 based single board computer
SOMRT1061 - i.MX RT1061 based module
MODRT1171 - i.MX RT1176 based module
MOD5441X - MCF5441X ColdFire based module
NANO54415 - MCF54415 ColdFire based module

SPI Peripherals Demonstrated

The application interfaces with the following Microchip SPI devices:

25LC020A EEPROM - 2Kbit (256 x 8) serial EEPROM
TC77-5.0 - Thermal sensor with 3-wire SPI interface
MCP3201 ADC - 2.7V 12-bit Analog-to-Digital Converter
MCP4822 DAC - Dual 12-bit Digital-to-Analog Converter with internal 2.048V reference
MCP41010 - 256-position single digital potentiometer
MCP6S92 - Single-ended, rail-to-rail I/O, low-gain Programmable Gain Amplifier (PGA)
MCP23S08 - 8-bit I/O expander connected to LEDs

Features

Web Interface

Access the built-in web page at http://<device-ip>/ for:

SPI device table with part numbers and descriptions
Serial console command reference
Per-platform hardware connection guide
DSPI API reference

Interactive Serial Menu

The application provides a serial console menu with the following options:

1 - Erase EEPROM (fill with 0xFF)
2 - Read EEPROM and display contents in hex format
3 - Write incrementing sequence to EEPROM (0x00, 0x01, 0x02...)
A - Read ADC voltage value
D - DAC ramp test on both channels (press any key to stop)
G - Programmable Gain Amplifier (PGA) gain sweep
T - Read temperature sensor (Fahrenheit, Celsius, Kelvin)
P - Set digital potentiometer (prompts for wiper value 0-255)
L - Toggle LEDs on the MCP23S08 GPIO expander

Hardware Pin Connections

The SPI pin map and peripheral selection (controller, chip select) for every supported platform live in SpiPinConfig.h, which UserMain() applies through a common set of SPI_CFG_*() macros. A few platforms also include commented-out alternate pinouts in that header (e.g. LPSPI1 on MODRT1171, LPSPI2 on SOMRT1061) that can be swapped in by commenting out the active set.

MODM7AE70 (P2 Header)

Signal	Header Pin	Function
CS	P2[30]	SPI0 NPCS2 - Chip Select
SCK	P2[25]	SPI0 SPCK - Clock
MISO	P2[27]	SPI0 MISO - Data In
MOSI	P2[28]	SPI0 MOSI - Data Out

SBE70LC (J1 Header)

Signal	Header Pin	Function
CS	J1[14]	SPI0 NPCS0 - Chip Select
SCK	J1[7]	SPI0 SPCK - Clock
MISO	J1[6]	SPI0 MISO - Data In
MOSI	J1[4]	SPI0 MOSI - Data Out

SOMRT1061 (Module Pins)

Signal	Module Pin	Function
CS	Pin 26	LPSPI1 PCS0 - Chip Select
SCK	Pin 27	LPSPI1 SCK - Clock
MISO	Pin 24	LPSPI1 SDI - Data In
MOSI	Pin 25	LPSPI1 SDO - Data Out

MODRT1171 (P1 Header)

Signal	Header Pin	Function
CS	P1[43]	LPSPI5 PCS0 - Chip Select
SCK	P1[42]	LPSPI5 SCK - Clock
MISO	P1[45]	LPSPI5 SDI - Data In
MOSI	P1[44]	LPSPI5 SDO - Data Out

MOD5441X (J2 Header)

Signal	Header Pin	Function
CS	J2[30]	DSPI1 PCS0 - Chip Select
SCK	J2[25]	DSPI1 SCK - Clock
MISO	J2[27]	DSPI1 SIN - Data In
MOSI	J2[28]	DSPI1 SOUT - Data Out

NANO54415 (Module Pins)

Signal	Module Pin	Function
CS	Pin 15	DSPI1 PCS0 - Chip Select
SCK	Pin 31	DSPI1 SCK - Clock
MISO	Pin 33	DSPI1 SIN - Data In
MOSI	Pin 35	DSPI1 SOUT - Data Out

Also connect GND and 3.3V to power the PicKit board.

Key Functions

EEPROM Operations (25LC020A)

EepromWriteBuf() - Writes data with automatic 16-byte page boundary handling and write-enable/WIP polling
EepromRead() - Reads data from the EEPROM

Sensor Reading

GetTemp() - Reads the TC77 thermal sensor over its 3-wire SPI bus (tri-states MOSI to read, then restores it)
ReadADC() - Reads the MCP3201 12-bit ADC and converts to voltage (3.3V reference)
LoopDAC() - Ramps the MCP4822 dual DAC output on both channels until a key is pressed

Configuration / Control

SetPotentiometer() - Sets the MCP41010 wiper position (0-255)
SetPGA() - Sweeps the MCP6S92 amplifier through its gain settings
ToggleLEDs() - Toggles the LEDs via the MCP23S08 GPIO expander

Technical Details

3-wire SPI (TC77)

The TC77 temperature sensor shares MOSI and MISO on a single data line. Before reading the sensor the example tri-states the MOSI pin, performs the read, then restores the pin to its SPI function. The 13-bit signed temperature reading is sign-extended before scaling at 0.0625 degrees C per LSB.

Data Conversion

ADC values are converted to voltage (3.3V reference, 12-bit resolution)
DAC values support a 0-2.048V reference with 2x output gain (10-bit ramp in this example)
Temperature is reported in Fahrenheit, Celsius, and Kelvin

Usage Instructions

Connect the Microchip PicKit Serial SPI Demo Board to your NetBurner development board's SPI pins (CS, SCK, MISO, MOSI, GND, 3.3V) per the table above
Compile and load the application onto your target platform
Access the web interface at http://<device-ip>/ for documentation
Connect to the serial console (typically 115200 baud)
Use the interactive menu to test different SPI peripherals

Troubleshooting

If the TC77 read reports "Error: TC77 not detected":

Verify the PicKit board is properly connected
Confirm the MISO/MOSI wiring matches the table for your platform
Ensure correct voltage levels (3.3V)

Requirements

NetBurner development tools and runtime system
Microchip PicKit Serial SPI Demo Board
Compatible NetBurner hardware platform

Project Structure

PicKitSerialSPIDemoBd/
+-- src/
|   +-- main.cpp        - Main application code
|   +-- SpiPinConfig.h  - Per-platform SPI pin map & peripheral selection
|   +-- htmldata.cpp    - Auto-generated web content
+-- html/
|   +-- index.html    - Web documentation page
|   +-- style.css     - Self-contained stylesheet
|   +-- logo.png      - NetBurner logo
+-- makefile          - Build configuration
+-- ReadMe.txt        - This file