IIO Demo no-OS Example Project

See projects/iio_demo (doxygen) for the Doxygen documentation.

Overview

The IIO Demo project runs an IIO (Industrial I/O) server on the target board, exposing demo ADC and DAC devices to any IIO client. The demo devices use loopback buffers, so data written to the DAC can be read back from the ADC, making this project a self-contained reference for the no-OS IIO framework that requires no external hardware.

Because the demo devices are entirely software based, this project is also a convenient way to bring up and validate a new board port: it exercises the UART/USB/Wi-Fi transport, the IRQ and timer infrastructure, and the IIO stack without depending on any physical sensor being present.

If you are not familiar with the ADI IIO Application, please take a look at: IIO No-OS

If you are not familiar with the ADI IIO-Oscilloscope Client, please take a look at: IIO Oscilloscope

No-OS Build Setup

Please see: No-OS Build Guide

No-OS Supported Examples

The initialization data used in the examples is taken out from the Project Common Data Path.

The macros used in Common Data are defined in platform specific files found in the Project Platform Configuration Path.

Each example is selected with its own --variant (the .conf files in the project directory). Not every variant is available on every board; see the combination list with python tools/scripts/no_os_build.py list --project iio_demo.

IIO example

The iio example instantiates the demo ADC and DAC devices and launches an IIOD server over the board's UART. Data written to the DAC loopback buffer can be read back from the ADC, so no external hardware is required. Using the IIO Oscilloscope application (or the iio_readdev / iio_writedev command line tools), users can access device attributes such as sampling frequency, scale, and offset and stream buffered data.

This example is built by selecting the iio variant (see the Build Command sections below).

IIO Timer Trigger example

The iio_timer_trigger example demonstrates buffered data acquisition driven by a hardware timer trigger. A periodic timer interrupt paces the sampling of the demo ADC, feeding the IIO buffer at a deterministic rate. This showcases the no-OS IIO trigger infrastructure without needing an external trigger source.

This example is built by selecting the iio_timer_trigger variant (see the Build Command sections below).

IIO USB UART example

The iio_usb_uart example is functionally identical to the basic iio example, but exposes the IIOD server over a USB CDC-ACM (virtual serial) interface instead of a physical UART. The board enumerates as a serial device on the host, and the IIO client connects to that virtual COM port.

This example is built by selecting the iio_usb_uart variant (see the Build Command sections below).

IIO Wi-Fi example

The iio_wifi example runs the IIOD transport over an ESP8266 Wi-Fi module (driven via UART AT commands) instead of the serial backend. The board connects to the configured access point and the IIO client connects to the reported IP address, allowing remote access to the demo devices over the network.

Set the network credentials in the iio_wifi defconfig via CONFIG_WIFI_SSID and CONFIG_WIFI_PWD before building.

This example is built by selecting the iio_wifi variant (see the Build Command sections below).

IIO Wi-Fi with Software Trigger example

The iio_wifi_with_sw_trig example combines the Wi-Fi transport with a software trigger for buffered data acquisition. As with iio_wifi, the IIOD server is reachable over the network. The software trigger requires networking and is therefore not supported over a plain UART backend.

Set the network credentials in the iio_wifi_with_sw_trig defconfig via CONFIG_WIFI_SSID and CONFIG_WIFI_PWD before building.

This example is built by selecting the iio_wifi_with_sw_trig variant (see the Build Command sections below).

Interacting with the device

Once the board is running, an IIO client such as iio_writedev / iio_readdev can be used to write to and read from the demo devices.

Write to device:

cat sample.dat | iio_writedev -u serial:/dev/ttyUSB0,921600 -b 400 demo_device

Read from device:

iio_readdev -u serial:/dev/ttyUSB0,921600 -b 400 -s 6400 demo_device > sample.dat

On Windows, use the COM port name for the serial URI:

Get-Content ascii.dat | iio_writedev -u serial:COM9,921600 -b 100 -s 100 demo_device_output
iio_readdev -u serial:COM9,921600 -b 100 -s 100 demo_device_input voltage0 voltage1

No-OS Supported Platforms

All platforms below are built through the unified no-OS CMake build flow using tools/scripts/no_os_build.py. Because the demo devices are software loopbacks, no external sensor wiring is required for any platform; simply connect the board to the host (typically over USB).

ADuCM Platform

Used Hardware

EVAL-ADICUP3029
An ESP8266 Wi-Fi module (only for the iio_wifi / iio_wifi_with_sw_trig variants)

Connections

No external sensor connections are required. Connect the EVAL-ADICUP3029 to the host via its USB port for both power and the serial console. For the Wi-Fi variants, attach the ESP8266 module to the UART pins used by the platform configuration.

Build Command

Available variants: iio, iio_wifi, iio_wifi_with_sw_trig. Available boards: eval-adicup3029. Replace --variant accordingly.

# point at the CrossCore Embedded Studio install (only if not auto-detected)
export CCES_HOME=/opt/analog/cces/3.0.3

cd no-OS

# build the iio example on the EVAL-ADICUP3029
python tools/scripts/no_os_build.py build \
   --project iio_demo --variant iio --board eval-adicup3029

# build the iio example over Wi-Fi (ESP8266)
python tools/scripts/no_os_build.py build \
   --project iio_demo --variant iio_wifi --board eval-adicup3029

# build and flash (requires a connected debug probe)
python tools/scripts/no_os_build.py build \
   --project iio_demo --variant iio --board eval-adicup3029 \
   --probe openocd --flash

The iio_wifi variants run the IIOD transport over an ESP8266 Wi-Fi module (UART AT commands) instead of the serial backend. Set the network credentials in the iio_wifi (or iio_wifi_with_sw_trig) defconfig via CONFIG_WIFI_SSID and CONFIG_WIFI_PWD before building, for example:

CONFIG_WIFI_SSID="MyNetwork"
CONFIG_WIFI_PWD="MyPassword"

Maxim Platform

Used Hardware

Connections

No external sensor connections are required. Connect the chosen Maxim board to the host via its USB port for power and the serial console.

Build Command

Available variants: iio, iio_usb_uart. Available boards: max32650fthr, max32655fthr, max32666fthr, max78000fthr (iio); ad-apard32690-sl, max32650fthr, max32666fthr (iio_usb_uart). Replace --variant / --board accordingly. Not every variant is available on every board; see the combination list with python tools/scripts/no_os_build.py list --project iio_demo.

# point at the Maxim SDK libraries (only if not auto-detected)
export MAXIM_LIBRARIES=</path/to/MaximSDK/Libraries>

cd no-OS

# build the iio example on the max32650fthr board
python tools/scripts/no_os_build.py build \
   --project iio_demo --variant iio --board max32650fthr

# build and flash (requires a connected debug probe)
python tools/scripts/no_os_build.py build \
   --project iio_demo --variant iio --board max32650fthr \
   --probe openocd --flash

STM32 Platform

Used Hardware

SDP-K1
NUCLEO-F413ZH
ST debugger

Connections

No external sensor connections are required. Connect the chosen STM32 board to the host via its USB port for power and the serial console.

Build Command

Available variants: iio, iio_timer_trigger, iio_usb_uart. Available boards: sdp-ck1z (all three variants); nucleo-f413zh (iio_usb_uart). Replace --variant / --board accordingly. Not every variant is available on every board; see the combination list with python tools/scripts/no_os_build.py list --project iio_demo.

# set the path to STM32CubeMX and STM32CubeIDE (only if they are not
# in a default install location)
export STM32CUBEMX=</path/to/stm32cubemx>
export STM32CUBEIDE=</path/to/stm32cubeide>

cd no-OS

# build the iio example on the sdp-ck1z board
python tools/scripts/no_os_build.py build \
   --project iio_demo --variant iio --board sdp-ck1z

# build and flash (requires a connected debug probe)
python tools/scripts/no_os_build.py build \
   --project iio_demo --variant iio --board sdp-ck1z \
   --probe openocd --flash

Pico Platform

Used Hardware

Raspberry Pi Pico

Connections

No external sensor connections are required. Connect the Raspberry Pi Pico to the host via its USB port for power and the serial console.

Build Command

Available variants: iio. Available boards: rpi-pico. Replace --variant / --board accordingly.

cd no-OS

# build the iio example on the Raspberry Pi Pico
python tools/scripts/no_os_build.py build \
   --project iio_demo --variant iio --board rpi-pico

# build and flash (requires a connected debug probe)
python tools/scripts/no_os_build.py build \
   --project iio_demo --variant iio --board rpi-pico \
   --probe openocd --flash