AMG8833: 8×8 IR Thermal Camera Array (Grid-EYE)

Working Principle

The AMG8833 (Grid-EYE) from Panasonic is an 8 × 8 infrared thermal imaging sensor that measures the temperature of 64 individual pixels across a 60° × 60° field of view. Each pixel is a thermopile — a series of micro-thermocouple junctions that generate a voltage proportional to the infrared radiation (8–14 µm) received from objects in its field of view. The sensor outputs a 64-element temperature array over I²C at up to 10 Hz.

Unlike single-point IR sensors (like the MLX90614), the AMG8833 provides spatial thermal information, enabling heat mapping, person detection, and thermal imaging at a fraction of the cost of professional thermal cameras. Resolution can be enhanced by software interpolation (bilinear/bicubic) from 8×8 to higher display resolutions.

Electrical Characteristics

Parameter	Value
Resolution	8 × 8 pixels (64 thermopiles)
Temperature Range	0–80 °C object (high gain) / −20 to 100 °C (extended)
Accuracy	±2.5 °C (or ±4.5 °C at edges)
Temperature Resolution	0.25 °C per LSB
Field of View	60° × 60°
Frame Rate	1 or 10 Hz (selectable)
Interface	I²C (0x68 or 0x69, selectable via pad)
Supply Voltage	3.3 V
Current Draw	~4.5 mA active, ~0.8 mA standby
Interrupt	Programmable per-pixel temperature threshold interrupt

Interfacing with an MCU

Connect 3.3 V, GND, SDA, SCL, and optionally INT (for thermal alarm interrupts). Read 128 bytes (64 pixels × 2 bytes each, 12-bit signed) from registers 0x80–0xFF. The Adafruit AMG88xx library handles the register reads and temperature conversion. For display, map pixel temperatures to a colour gradient (blue=cold → red=hot) on an OLED or TFT screen.

Calibration

• Internal thermistor: The AMG8833 has an on-die thermistor for ambient temperature compensation; read register 0x0E–0x0F to verify
• Emissivity assumption: The sensor assumes emissivity ε = 1.0 (blackbody). For shiny or metallic surfaces, actual temperature will be higher than reported
• Cross-pixel uniformity: Edge pixels may have slightly higher error; apply per-pixel offset correction if precision matters
• Distance/FOV: Each pixel covers 7.5° × 7.5°; at 1 m distance, each pixel sees approximately 13 cm × 13 cm

Code Example

/*
 * AMG8833 8×8 Thermal Camera — Arduino
 * Library: Adafruit_AMG88xx (install via Library Manager)
 * Wiring: 3.3V, GND, SDA, SCL
 */
#include <Wire.h>
#include <Adafruit_AMG88xx.h>

Adafruit_AMG88xx amg;
float pixels[AMG88xx_PIXEL_ARRAY_SIZE]; /* 64 floats */

void setup() {
    Serial.begin(115200);
    if (!amg.begin()) {
        Serial.println("AMG8833 not found!");
        while (1);
    }
    Serial.println("AMG8833 Thermal Camera Ready");
    delay(100);
}

void loop() {
    amg.readPixels(pixels);

    /* Print 8x8 thermal grid */
    float minT = 999, maxT = -999;
    for (int row = 0; row < 8; row++) {
        for (int col = 0; col < 8; col++) {
            float t = pixels[row * 8 + col];
            if (t < minT) minT = t;
            if (t > maxT) maxT = t;
            Serial.print(t, 1);
            Serial.print("	");
        }
        Serial.println();
    }
    Serial.print("Range: ");
    Serial.print(minT, 1); Serial.print(" - ");
    Serial.print(maxT, 1); Serial.println(" C
");

    /* Simple person detection */
    if (maxT > 28.0) {
        Serial.println("** WARM OBJECT DETECTED **");
    }
    delay(500);
}

Real-World Applications

Limitations

• Low resolution: 8×8 pixels is extremely coarse; fine details are lost. Cannot identify faces or read text.
• Limited range: 0–80 °C standard; cannot measure high-temperature sources (soldering irons, flames).
• Emissivity dependent: Shiny and metallic surfaces reflect ambient IR, giving false-low readings.
• Distance limitation: At 5+ metres, each pixel covers a large area; individual hotspots become unresolvable.
• No video stream: 10 Hz max; not suitable for fast-moving thermal events.