{"title":"Adafruit ATtiny816 Breakout with seesaw - STEMMA QT / Qwiic","handle":"adafruit-attiny816-breakout-with-seesaw-stemma-qt-qwiic","url":"/products/adafruit-attiny816-breakout-with-seesaw-stemma-qt-qwiic","description":"The Adafruit ATtiny816 Breakout with seesaw is a compact development board that combines an ATtiny816 microcontroller with the Adafruit seesaw I2C framework and STEMMA QT connectivity. Pre-programmed with seesaw firmware, it acts as an I2C-controlled co-processor — adding GPIO, ADC, PWM, and NeoPixel support to any I2C-capable host.\n\nThis board offers the same pin layout and seesaw capabilities as the ATtiny1616 variant but with a smaller memory footprint, making it a cost-effective option for projects that don't need the extra flash and RAM. It can also be reprogrammed as a general-purpose ATtiny816 development board using the megaTinyCore Arduino core.\n\nKey Features\n\n\nATtiny816 Microcontroller – 8KB flash, 512 bytes RAM, 128 bytes EEPROM, internal oscillator up to 20 MHz, hardware multiplier\n\nSeesaw I2C Framework – Universal converter providing GPIO, ADC, PWM, and NeoPixel control over I2C\n\n12× GPIO – Pins 0–5, 6, 8, 11, 14, 15, 16 with selectable pullup resistors\n\n9× 10-bit ADC Inputs – Pins 0, 1, 2, 3, 4, 5, 14, 15, 16\n\n5× 8-bit PWM Outputs – Pins 0, 1, 7, 11, 16\n\nNeoPixel Output – Drive up to 60 NeoPixel LEDs from a single pin\n\n127-byte EEPROM – Non-volatile memory for tokens or MAC addresses (last byte used for I2C address)\n\nInterrupt Output – Pin 6, triggered by any configured peripheral\n\n2× I2C Address Selection Pins – Pins 12 and 13 for running multiple boards on one bus\n\n2× STEMMA QT / Qwiic Connectors – Plug-and-play I2C with 10K pullup resistors\n\n3.3V Regulator – Runs at Vin by default (up to 5V); solder jumper to select 3.3V logic\n\n2V to 5V Operation – Wide voltage range for flexible integration\n\nPower and Activity LEDs – Green power LED, red indicator LED on pin 10\n\n\nAlso Available\n\n\nATtiny1616 Seesaw Breakout with STEMMA QT – More memory (16KB flash, 2KB RAM) and up to 250 NeoPixels\n\nATSAMD09 Seesaw Breakout – Original seesaw breakout with ARM Cortex-M0+ (requires J-Link for reprogramming)\n\n\nIdeal For\n\nAdding extra I/O to Raspberry Pi, ESP32, or Arduino projects via I2C\nNeoPixel control from I2C-only platforms\nATtiny816 development and prototyping\nCost-effective seesaw peripheral in space-constrained designs\n\n\nPackage Contents\n\n1× Adafruit ATtiny816 Breakout with seesaw\n1× Header strip set\n\n\n\nNote: This board does not include a bootloader. To reprogramme or customise the seesaw firmware, you will need a UPDI programmer (which can be made from a USB-to-serial cable and a single 4.7K or 10K resistor). The firmware is compiled using megaTinyCore. No support is provided for custom seesaw builds.\n","vendor":"Adafruit","product_type":"physical","in_stock":true,"options":[],"variants":[{"id":1734,"title":"Default Title","sku":"AF-5681","price":10.11,"on_sale":false,"in_stock":true,"available_quantity":29,"option1":"Default Title"}]}