No-OS User Guide

This user guide uses no-OS's documentation and supports the carriers NUCLEO-H503RB and NUCLEO-H563ZI. For linux, see Linux User Guide,

Building the firmware

For no-OS:

Follow the no-OS build guide to set up your development environment and build the firmware for the AD405X project.

For Linux:

Follow the Kuiper Linux documentation to prepare an SD card with the latest Kuiper image. The AD4062 Linux driver and devicetree are included in recent Kuiper releases.

Hardware setup

Before writing the no-OS firmware, set up the hardware with following steps:

  • Disconnect both the evaluation board and the carrier from all power sources.

  • Connect the evaluation board to the carrier using the Arduino Uno compatible headers (there is only one position where all pins are connected).

  • Check jumpers and powering on instructions specific for the carrier.

  • When powering the evaluation board from the carrier, follow:

    • Set JP2 jumper on the evaluation board to the +5V position. This position connects the evaluation board power management circuitry to the +5 V pin on the Arduino Uno power header.

    • Connect the carrier to a PC with a USB cable, the evaluation board DS1 LED should turn on, as well as other LEDs on the carrier.

  • When powering the evaluation board from an external power supply, follow:

    • Set JP2 jumper on the evaluation board to the VIN position. This position connects the evaluation board power management circuitry to the VIN pin on the Arduino Uno power header.

    • Power on the carrier via the external power supply option (in general, via a DC jack), the evaluation board DS1 LED should turn on, as well as other LEDs on the carrier.

    • Connect the carrier to a PC with a USB cable.

I3C Address Configuration

The AD4060/AD4062 include three digital input pins ADDR0, ADDR1, and ADDR2. The ADDR[2:0] pins enable the assignment of up to eight unique part instance values to support up to eight AD4060/AD4062s on one I3C bus.

The evaluation board’s jumpers JP11, JP12, and JP10 allow for setting the ADDR0, ADDR1, and ADDR2 respectively to either VIO or GND.

Flashing the firmware

These steps are done after the hardware setup, with the board powered on and connected to a PC.

Build the no-OS firmware following the build guide. The AD405X project supports multiple examples:

  • basic_i3c_example: Interactive example for I3C devices that prints samples and waits for threshold events

  • i3c_dma_example: I3C example with DMA support

  • iio_example: TinyIIO server for use with libiio clients

See AD405X no-OS Example Project STM32 for detailed build and flash instructions. Flash the built .elf file to the STM32 board using STM32 Cube IDE or by copying to the USB mass storage device.

Quick start

Connect a precision signal source or signal generator to the analog input Subminiature Version A (SMA) connectors to drive the AD4060/AD4062 inputs into their specified operating ranges.

https://media.githubusercontent.com/media/analogdevicesinc/documentation/main/docs/solutions/reference-designs/ad4062-ardz/user-guide/signal-bias.png

Figure 1 Biasing the EVAL-AD4062-ARDZ Inputs Without Signal Generator Hardware for Software Validation

If no signal generator is available, a jumper cable between the VREF and VCM test points can be used to bias the AD4060/ AD4062 analog inputs to VREF. This is preferred over connecting the amplifier inputs to GND, because the amplifier VEE rails are connected to GND by default.

Evaluation board hardware

The evaluation board includes the AD4060/AD4062 with companion circuitry for an out-of-the-box evaluation experience:

  • ADC: AD4060BCPZ/AD4062BCPZ (14-lead LFCSP)

  • Voltage reference: MAX6070 2.5V low-noise reference

  • Amplifiers: Two MAX44260 low-power, rail-to-rail op amps

  • Power regulator: ADP7118 3.3V LDO regulator

Digital Interface

The AD4060/AD4062 digital interface includes:

  • I3C bus: For reading and writing data (SDA and SCL on Arduino headers)

  • GP0/GP1: Two programmable GPIOs with multiple functions:

    • Data Ready (RDY) signal

    • Threshold interrupt (GP_INTR)

    • Device enable (DEV_EN) for AFE power cycling

    • Static high/low outputs

    • GPIO controller functionality (Linux only)

  • EEPROM: On-board I2C EEPROM for board identification

Power Domains

The evaluation board operates on the following power domains:

Power Rail

Source

Default Voltage

+5V/VIN

Arduino header (from carrier)

5V

VSUPPLY

ADP7118 LDO regulator

3.3V

VDD

VSUPPLY (via JP8)

3.3V

VIO

IOREF from carrier (via JP1)

3.3V

VREF

MAX6070 reference

2.5V

For more detailed hardware information, see the EVAL-AD4060/AD4062 User Guide.

Interfacing with TinyIIO

The no-OS driver supports the AD4060/AD4062 I3C devices through a core driver and a TinyIIO layer. The TinyIIO layer exposes the device to Libiio clients running on a host PC over a serial connection.

For language bindings and high level GUI tools see Libraries and GUI Tools.

Connecting to the device

Execute on the host PC to list the device:

~$

iio_info -u serial:/dev/ttyACM0,115200,8n1

This will display the IIO device information, available channels and attributes.

Available channels

The no-OS TinyIIO implementation exposes two channels:

  • voltage_adc_mode (channel 0): Standard ADC mode, single sample per conversion

  • voltage_burst_averaging_mode (channel 1): Burst averaging mode with oversampling

Channel attributes

Each channel provides the following attributes:

  • raw: Read the raw ADC value (integer)

  • sample_rate: Configure the internal sample rate in Hz (read/write)

  • avg_filter_length: Configure the averaging filter length for burst mode (read/write)

Reading a single sample

To read a single sample from the ADC mode channel:

~$

iio_attr -u serial:/dev/ttyACM0,115200,8n1 -c ad4062 voltage_adc_mode raw

To read from the burst averaging mode channel:

~$

iio_attr -u serial:/dev/ttyACM0,115200,8n1 -c ad4062 voltage_burst_averaging_mode raw

Configuring sample rate

View the current sample rate:

~$

iio_attr -u serial:/dev/ttyACM0,115200,8n1 -c ad4062 voltage_adc_mode sample_rate

Set a new sample rate (in Hz):

~$

iio_attr -u serial:/dev/ttyACM0,115200,8n1 -c ad4062 voltage_adc_mode sample_rate 1000000

Available sample rates: 2000000, 1000000, 333000, 100000, 33000, 10000, 3000, 1000, 500, 333, 250, 200, 166, 140, 125, 111 Hz.

Configuring averaging

For burst averaging mode, configure the filter length:

~$

iio_attr -u serial:/dev/ttyACM0,115200,8n1 -c ad4062 voltage_burst_averaging_mode avg_filter_length 8

Capturing buffered data

To capture a stream of samples to a buffer:

~$

iio_readdev -u serial:/dev/ttyACM0,115200,8n1 -s 1024 -b 256 ad4062 voltage_adc_mode > data.bin

This captures 1024 samples in buffers of 256 samples each.

tinyIIO limitations

Not all driver features are exposed through tinyIIO, in particular, threshold events are not available as IIO events like in the linux driver, still, an example that demos threshold events without tinyIIO is provided.

References