AMU Library

A C/C++ library for communicating with AMU (Aerospace Measurement Unit) devices over the I2C or USB interface.

Overview

This Arduino-compatible library provides a comprehensive interface for controlling and reading data from AMU devices via I2C communication. The library supports multiple AMU devices on the same I2C bus and includes SCPI-based communication capabilities.

Features

• I2C Communication: Full support for communicating with AMU devices over the I2C bus
• Multi-device Support: Connect and control multiple AMU devices on the same bus
• Arduino Compatible: Designed to work seamlessly with Arduino and PlatformIO projects
• SCPI Support: Built-in SCPI (Standard Commands for Programmable Instruments) protocol support
• Measurement Capabilities:
  • Voltage measurements
  • Current measurements
  • Temperature sensor readings (multiple sensors)
  • Programmable gain amplifier (PGA) control
• Device Control:
  • LED color and pattern control
  • Channel activation/deactivation
  • Sleep mode management
  • Device information retrieval (serial number, firmware version, notes)

Installation

Arduino IDE

1. Download this library as a ZIP file
2. In Arduino IDE, go to Sketch → Include Library → Add .ZIP Library
3. Select the downloaded ZIP file

PlatformIO

Add the following to your platformio.ini file:

lib_deps = 
    https://github.com/the-aerospace-corporation/amulib.git

Quick Start

#include <Wire.h>
#include <amulib.h>

AMU amu;

void setup() {
    Serial.begin(115200);
    Wire.begin();
    Wire.setClock(400000);
    
    // Initialize AMU device at I2C address 0x0B
    amu.begin(0x0B);
    
    // Wait for device to be ready
    if (amu.waitUntilReady(5000) == 0) {
        Serial.println("AMU device ready!");
    }
}

void loop() {
    // Read voltage
    float voltage = amu.measureVoltage();
    Serial.print("Voltage: ");
    Serial.println(voltage);
    
    // Read current
    float current = amu.measureCurrent();
    Serial.print("Current: ");
    Serial.println(current);
    
    // Read temperature
    float temp = amu.measureTSensor();
    Serial.print("Temperature: ");
    Serial.println(temp);
    
    delay(1000);
}

Examples

The library includes several example projects:

• simple: Basic AMU communication and measurement example
• iv_sweep: Current-voltage sweep measurements
• twi_passthrough: I2C passthrough functionality

Each example includes its own platformio.ini configuration and can be built independently.

API Reference

Initialization

• begin(uint8_t twiAddress) - Initialize AMU with I2C address
• begin(uint8_t twiAddress, amu_transfer_fptr_t i2c_transfer_func) - Initialize with custom I2C transfer function
• waitUntilReady(uint32_t timeout) - Wait for device to be ready

Measurements

• measureVoltage() - Read voltage measurement
• measureCurrent() - Read current measurement
• measureTSensor() - Read primary temperature sensor
• measureTSensor0() - Read temperature sensor 0
• measureTSensor1() - Read temperature sensor 1
• measureTSensor2() - Read temperature sensor 2

Device Control

• setActiveChannels(uint16_t channels) - Set active measurement channels
• setLEDcolor(float red, float grn, float blu) - Set LED color
• setLEDmode(amu_led_pattern_t mode) - Set LED pattern mode
• sleep() - Put device into sleep mode
• getPGA(AMU_ADC_CH_t channel) - Get programmable gain amplifier setting

Device Information

• readSerialStr() - Read device serial number
• readFirmwareStr() - Read firmware version
• readNotes(char* notes) - Read device notes

Hardware Requirements

• Arduino or compatible microcontroller with I2C support
• AMU device(s)
• I2C pull-up resistors (typically 4.7kΩ)

License

This library is released under the MIT License. See the LICENSE file for details.

Author

Colin Mann - Aerospace Corporation

Version

Current version: 2.1

Contributing

Contributions are welcome! Please feel free to submit pull requests or open issues for bugs and feature requests.