M5Stack Analog to I2C Unit 4-20mA Input

Description

The Analog to I2C Unit 4-20mA Input, also documented as Unit AIN4-20mA, is a single-channel 4-20mA current analog measurement unit for M5Stack systems. It uses an STM32G030F6 controller and communicates with the host through I2C, so a controller can read industrial current sensor data without handling raw analog conversion directly.

The 4-20mA I2C measurement unit supports both 2-wire and 4-wire sensor wiring through jumper cap configuration. Its onboard power isolation chip and op-amp circuit help the isolated current sensor unit measure external current sensors accurately while improving signal integrity and system safety.

Features

• Single-channel 4-20mA acquisition: reads current analog signals from industrial sensors.
• I2C host communication: the Analog to I2C Unit 4-20mA Input communicates at I2C address 0x55.
• 2-wire and 4-wire support: jumper caps switch between internal and external power supply wiring modes.
• Isolated measurement path: the isolated current sensor unit uses HCNR200 signal isolation and SGM321YC5/TR op-amp circuitry.
• STM32 controller: STM32G030F6P6 handles measurement processing and I2C data output.
• Development support: the Unit AIN4-20mA supports Arduino, UIFlow, and related firmware resources.

Specifications

Applications

• Power system equipment monitoring
• Motor control and industrial feedback loops
• Energy management and data collection
• Automation and industrial process control
• 4-20mA pressure, flow, level, or temperature transmitter reading

Product List

Other Content

Jumper caps select the wiring mode of the 4-20mA I2C measurement unit. For a passive current-type sensor, connect the DC 24V power supply input, connect the sensor signal to IN+ and IN-, and set the jumper caps to the passive wiring position. For an active current-type sensor, connect the sensor signal to IN+ and IN- and set the jumper caps to the active wiring position.

Before commissioning the isolated current sensor unit, confirm the sensor type, jumper position, and power wiring. A known current source or calibrated transmitter is recommended for checking the Unit AIN4-20mA reading range.

Resources

• Product documentation
• Schematic PDF
• Arduino library
• UIFlow1 documentation
• UIFlow2 documentation
• Internal firmware
• Passive sensor wiring diagram
• Active sensor wiring diagram
• STM32G030F6 datasheet
• HCNR200 datasheet
• SGM321YC5 datasheet

FAQ

What type of signal does the Unit AIN4-20mA measure?

It measures a single-channel 4-20mA current signal and makes the reading available to the host through I2C.

Can it work with passive and active current sensors?

Yes. The Analog to I2C Unit 4-20mA Input supports both wiring types through jumper cap configuration.

What should be checked before use?

Confirm the sensor wiring, jumper cap position, and power supply mode before relying on the 4-20mA I2C measurement unit in an automation system.