The part number **15284** most commonly refers to the **Adafruit Seesaw - I2C to Hardware Expander Breakout**. This component is a versatile tool designed to add more Input/Output (I/O) capabilities to a microcontroller (like an Arduino or Raspberry Pi) using only two wires via the I2C protocol. --- ### 1. Technical Specifications The core of this breakout is the **ATSAMD09** microcontroller, pre-programmed with Adafruit's "Seesaw" firmware. | Feature | Specification | | :--- | :--- | | **Interface** | I2C (Inter-Integrated Circuit) | | **Operating Voltage** | 3.3V to 5V DC | | **Microcontroller** | ATSAMD09 (ARM Cortex M0+) | | **GPIO Pins** | Up to 8 pins (configurable) | | **ADC Channels** | 3 x 10-bit Analog-to-Digital converters | | **PWM Outputs** | 1 x 16-bit Timer PWM | | **I2C Address** | 0x49 (Default, hardware configurable) | --- ### 2. Key Capabilities The 15284 (Seesaw) acts as a "bridge" to offload simple tasks from your main processor. * **GPIO Expansion:** Adds digital pins that can be used for reading buttons or driving LEDs. * **Analog Reading:** Allows you to read sensors (like potentiometers or light sensors) even if your main board (like a Raspberry Pi) lacks built-in ADC pins. * **PWM Control:** Can be used to dim LEDs or control small servos without jitter. * **EEPROM:** Includes a small amount of non-volatile memory to store settings or small strings of data. --- ### 3. Pinout Description The board typically features the following connection points: | Pin Type | Function | | :--- | :--- | | **VCC/GND** | Power input (3.3V or 5V) and Ground. | | **SDA/SCL** | I2C Data and Clock lines for communication with the host. | | **PA02, PA04, PA05** | Standard GPIO pins with ADC capabilities. | | **PA08, PA09, PA14** | Standard GPIO pins. | | **PA15** | GPIO pin often used for PWM. | --- ### 4. Common Use Cases 1. **Raspberry Pi Projects:** Adding analog inputs to a Pi, which natively only has digital GPIO. 2. **Reducing Pin Usage:** If you have an Arduino project with too many buttons/LEDs, you can move 8 of them to the Seesaw to save pins on the Arduino. 3. **Sensor Hubs:** Creating a modular sensor board that communicates entirely over I2C. ---