ADT7420-PMDZ no-OS Example Project

See projects/adt7420-pmdz (doxygen) for the Doxygen documentation.

The EVAL-ADT7420-PMDZ is a PMOD evaluation board for the ADT7420, a high accuracy digital temperature sensor. The ADT7420 provides 16-bit resolution (0.0078 degrees C) and communicates via an I2C interface. Its factory-set I2C address is 0x48, with options for modification via solder link configurations on pins A0 and A1, allowing up to four unique addresses. The ADT7420 operates over a supply voltage range of 2.7 V to 5.5 V with a typical supply current of 210 uA at 3.3 V. The device features programmable INT and CT open-drain outputs for over-temperature and critical temperature alert notifications.

Applications

RTD and thermistor replacement
Thermocouple cold junction compensation
Medical equipment
Industrial control and test
Food transportation and storage
Environmental monitoring and HVAC
Laser diode temperature control

Hardware Specifications

Power Supply Requirements

The EVAL-ADT7420-PMDZ is powered via the PMOD connector from the host board. The host board must provide a 3.3 V supply. The ADT7420 draws a typical supply current of 210 uA in normal operation mode. An onboard LED near component R5 indicates when power is applied.

Digital Interface

The EVAL-ADT7420-PMDZ uses an extended I2C PMOD interface, providing SCL, SDA, VDD, and GND connections through the standard 2x4 PMOD header (P1).

P1 Pin Configuration

Pin No.	Pin Function	Mnemonic
1	Serial Clock	SCL
2	Serial Clock	SCL
3	Serial Data	SDA
4	Serial Data	SDA
5	Digital Ground	DGND
6	Digital Ground	DGND
7	Digital Power	VDD
8	Digital Power	VDD

Jumper Configuration

The EVAL-ADT7420-PMDZ provides I2C address selection through solder links JP1 and JP2.

JP1 Position	JP2 Position	A1 Logic	A0 Logic	I2C Address
2 & 3 Short	2 & 3 Short	Low	Low	0x48
2 & 3 Short	1 & 2 Short	Low	High	0x49
1 & 2 Short	2 & 3 Short	High	Low	0x4A
1 & 2 Short	1 & 2 Short	High	High	0x4B

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: Project Common Data Path

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

Dummy example

This is a simple example that initializes the ADT7420 temperature sensor via I2C, reads the high and low temperature limit registers, calculates the current temperature using adt7420_get_temperature(), and configures the hysteresis register. The example runs in a continuous loop, periodically printing the current temperature and threshold values.

In order to build the dummy example, make sure you have the following configuration in the Makefile

# Select the example you want to enable by choosing y for enabling and n for disabling
DUMMY_EXAMPLE = y
IIO_EXAMPLE = n

IIO example

This project is actually a IIOD demo for EVAL-ADT7420-PMDZ. The project launches a IIOD server on the board so that the user may connect to it via an IIO client.

Using IIO-Oscilloscope, the user can configure the device.

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

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

The No-OS IIO Application together with the No-OS IIO ADT7420 driver take care of all the back-end logic needed to setup the IIO server.

This example initializes the IIO device and calls the IIO app as shown in: IIO Example

In order to build the IIO project make sure you have the following configuration in the Makefile

# Select the example you want to enable by choosing y for enabling and n for disabling
DUMMY_EXAMPLE = n
IIO_EXAMPLE = y

No-OS Supported Platforms

Maxim Platform

Used hardware

EVAL-ADT7420-PMDZ
Maxim platform board (MAX32650, MAX32655, MAX32660, MAX32665, MAX78000, or MAX32690)

Connections

Connect the EVAL-ADT7420-PMDZ PMOD connector to the I2C PMOD header on the Maxim platform board. The I2C SDA, SCL, VDD (3.3 V), and GND signals are routed through the PMOD connector.

Build Command

# to delete current build
make reset
# to build the project
make PLATFORM=maxim TARGET=max32690
# to flash the code
make run

Mbed Platform