# Adafruit ATtiny Breakouts with seesaw ## Overview ![](https://cdn-learn.adafruit.com/assets/assets/000/105/222/medium800thumb/adafruit_products_ATTiny_NeoPixel_ring.jpg?1633639240) These are the Adafruit ATtiny817, ATtiny816 and ATtiny1616 breakouts with seesaw! These breakout boards are a "three in one" product: 1. The ATtiny817, ATtiny816 and ATtiny1616 are part of the 'next gen' of AVR microcontrollers, and now we have a cute development/breakout board for them, with just enough hardware to get the chip up and running. 2. It's also an Adafruit seesaw board. Adafruit seesaw is a near-universal converter framework which allows you to add and extend hardware support to any I2C-capable microcontroller or microcomputer. Instead of getting separate I2C GPIO expanders, ADCs, PWM drivers, etc, seesaw can be configured to give a wide range of capabilities. 3. Finally, with STEMMA QT connectors on it, you could use it as either an I2C controller or peripheral with plug-and play support. ![](https://cdn-learn.adafruit.com/assets/assets/000/122/973/medium800/adafruit_products_5681-00.jpg?1690378338) We primarily designed this board for our own use: it's a mini dev board that lets us design with the ATtinyxxx, [just like we did for the ATSAMD09](https://www.adafruit.com/product/3657). With the 2021-2022 silicon shortage, we're adapting some of our SAMD09 designs to the ATtinyxxx series and wanted a quick minimal board to test code on. Each breakout comes with the assembled and tested board, as well as some header strips. Each PCB is fairly minimal and contains: ![](https://cdn-learn.adafruit.com/assets/assets/000/122/974/medium800/adafruit_products_5681-01.jpg?1690378354) ### **ATtiny817 8-bit microcontroller** - 8KB flash, 512 bytes of RAM, 128 bytes of EEPROM - Internal oscillator can run up to 20MHz - Internal hardware multiplier - Can run from 2V to 5V power/logic (check the datasheet for max speed at desired power) - **3.3V regulator** - by default we run at the Vin voltage, which can be 5V, but there's a solder jumper on the bottom if you'd like to select 3V logic. - **Green power LED** - **Red indicator LED** - **Two STEMMA QT I2C connectors** with 10K pullup resistors, connected to pins 10 and 11. The default I2C address is **0x49**. ![adafruit_products_5233-04.jpg](https://cdn-learn.adafruit.com/assets/assets/000/118/840/medium640/adafruit_products_5233-04.jpg?1677165021) ### **ATtiny816 8-bit microcontroller** - 8KB flash, 512 bytes of RAM, 128 bytes of EEPROM - Internal oscillator can run up to 20MHz - Internal hardware multiplier - Can run from 2V to 5V power/logic (check the datasheet for max speed at desired power) - **3.3V regulator**  - by default we run at the Vin voltage, which can be 5V, but there's a solder jumper on the bottom if you'd like to select 3V logic. - **Green power LED** - **Red indicator LED** - **Two STEMMA QT I2C connectors**  with 10K pullup resistors, connected to pins 8 and 9. The default I2C address is **0x49**. ![adafruit_products_5681-03.jpg](https://cdn-learn.adafruit.com/assets/assets/000/118/841/medium640/adafruit_products_5681-03.jpg?1677165064) ### **ATtiny1616 8-bit microcontroller** - 16KB flash, 2KB of RAM, 256 bytes of EEPROM - Internal oscillator can run up to 20MHz - Internal hardware multiplier - Can run from 2V to 5V power/logic (check the datasheet for max speed at desired power) - **3.3V regulator**  - by default we run at the Vin voltage, which can be 5V, but there's a solder jumper on the bottom if you'd like to select 3V logic. - **Green power LED** - **Red indicator LED** - **Two STEMMA QT I2C connectors**  with 10K pullup resistors, connected to pins 8 and 9. The default I2C address is **0x49**. ![adafruit_products_5690-04.jpg](https://cdn-learn.adafruit.com/assets/assets/000/118/842/medium640/adafruit_products_5690-04.jpg?1677165106) ![](https://cdn-learn.adafruit.com/assets/assets/000/105/225/medium800/adafruit_products_ATTiny_STEMMA_side.jpg?1633639282) [This boards comes pre-programmed with seesaw peripheral code](https://github.com/adafruit/Adafruit_seesawPeripheral) that will let it act as an "I2C to something" converter, basically a little I2C-controlled friend to do all the timing-sensitive things many microcontrollers and microcomputers are not good at. For example, using the ATtiny817 breakout with the pre-burned seesaw firmware gives you: - 14 x GPIO with selectable pullup resistors - 9 x 10-bit ADC inputs - pins 0, 1, 2, 3, 6, 7, 18, 19, 20 - 5 x 8-bit PWM outputs - pins 0, 1, 9, 12, 13 - 1 x NeoPixel output (up to 60 pixels) - 1 x EEPROM with 127 byte of NVM memory (handy for storing small access tokens or MAC addresses) - last byte of EEPROM is used for I2C address selection - 1 x Interrupt output that can be triggered by any of the accessories - pin 15 - 2 x I2C address selection pins - pins 16 and 17 - 1 x Activity LED on pin 5, tied active low Using the ATtinyx16 breakouts with pre-burned seesaw firmware gives you: - 12 x GPIO with selectable pullup resistors: 0-5, 6, 8, 11, 14, 15, 16 - 9 x 10-bit ADC inputs - pins 0, 1, 2, 3, 4, 5, 14, 15, 16 - 5 x 8-bit PWM outputs - pins 0, 1, 7, 11, 16 - 1 x NeoPixel output (up to 250 pixels) - 1 x EEPROM with 127 byte of NVM memory (handy for storing small access tokens or MAC addresses) - last byte of EEPROM is used for I2C address selection - 1 x Interrupt output that can be triggered by any of the accessories - pin 6 - 2 x I2C address selection pins - pins 12 and 13 - 1 x Activity LED on pin 10, tied active low ![](https://cdn-learn.adafruit.com/assets/assets/000/105/226/medium800/adafruit_products_ATTiny_back.jpg?1633639296) Of course you can configure or reprogram the chip to however you want to use it - [we like using SpenceKonde's megaTinyCore which brings Arduino peripheral support](https://github.com/SpenceKonde/megaTinyCore) to this series of chips. To program the chip [you will need a 'UPDI' programmer](https://github.com/SpenceKonde/megaTinyCore), which you can make with a [USB-to-Serial cable](https://www.adafruit.com/product/954) and [a single 4.7K or 10K resistor](https://www.adafruit.com/product/2783). **Please note:** The boards do not come with a bootloader. If you want to do development on seesaw (e.g. changing the configuration) you need a separate UPDI programming setup! [The firmware we put on is available as this example sketch](https://github.com/adafruit/Adafruit_seesawPeripheral/blob/main/examples/example_pid5233/example_pid5233.ino), compiled using the megaTinyCore. We don't provide any support for custom builds of seesaw - we think this is cool and useful for the Maker community! - [Next Page](https://learn.adafruit.com/adafruit-attiny817-seesaw/attinyx16-breakout-pinouts.md) ## Primary Products ### Adafruit ATtiny817 Breakout with seesaw - STEMMA QT / Qwiic [Adafruit ATtiny817 Breakout with seesaw - STEMMA QT / Qwiic](https://www.adafruit.com/product/5233) This breakout board is a "three in one" product: 1. The ATtiny817 is part of the 'next gen' of AVR microcontrollers, and now we have a cute development/breakout board for it, with just enough hardware to get the chip up and running. 2. It's also an Adafruit... In Stock [Buy Now](https://www.adafruit.com/product/5233) [Related Guides to the Product](https://learn.adafruit.com/products/5233/guides) ### Adafruit ATtiny816 Breakout with seesaw - STEMMA QT / Qwiic [Adafruit ATtiny816 Breakout with seesaw - STEMMA QT / Qwiic](https://www.adafruit.com/product/5681) This breakout board is a "three in one" product: 1. The ATtiny816 is part of the 'next gen' of AVR microcontrollers, and now we have a cute development/breakout board for it, with just enough hardware to get the chip up and running. 2. It's also an Adafruit... In Stock [Buy Now](https://www.adafruit.com/product/5681) [Related Guides to the Product](https://learn.adafruit.com/products/5681/guides) ### Adafruit ATtiny1616 Breakout with seesaw - STEMMA QT / Qwiic [Adafruit ATtiny1616 Breakout with seesaw - STEMMA QT / Qwiic](https://www.adafruit.com/product/5690) This breakout board is a "three in one" product: 1. The ATtiny1616 is part of the 'next gen' of AVR microcontrollers, and now we have a cute development/breakout board for it, with just enough hardware to get the chip up and running. 2. It's also an Adafruit... In Stock [Buy Now](https://www.adafruit.com/product/5690) [Related Guides to the Product](https://learn.adafruit.com/products/5690/guides) ## Featured Products ### STEMMA QT / Qwiic JST SH 4-Pin Cable - 50mm Long [STEMMA QT / Qwiic JST SH 4-Pin Cable - 50mm Long](https://www.adafruit.com/product/4399) This 4-wire cable is 50mm / 1.9" long and fitted with JST SH female 4-pin connectors on both ends. Compared with the chunkier JST PH these are 1mm pitch instead of 2mm, but still have a nice latching feel, while being easy to insert and remove. In Stock [Buy Now](https://www.adafruit.com/product/4399) [Related Guides to the Product](https://learn.adafruit.com/products/4399/guides) ### USB to TTL Serial Cable - Debug / Console Cable for Raspberry Pi [USB to TTL Serial Cable - Debug / Console Cable for Raspberry Pi](https://www.adafruit.com/product/954) The cable is easiest way ever to connect to your microcontroller/Raspberry Pi/WiFi router serial console port. Inside the big USB plug is a USB\<-\>Serial conversion chip and at the end of the 36" cable are four wire - red power, black ground, white RX into USB port, and green TX out... In Stock [Buy Now](https://www.adafruit.com/product/954) [Related Guides to the Product](https://learn.adafruit.com/products/954/guides) ## Related Guides - [Adafruit UPDI Friend](https://learn.adafruit.com/adafruit-updi-friend.md) - [Adafruit VEML6075 UVA / UVB / UV Index Sensor](https://learn.adafruit.com/adafruit-veml6075-uva-uvb-uv-index-sensor.md) - [Adafruit LM73100 Ideal Diode Breakout](https://learn.adafruit.com/adafruit-lm73100-ideal-diode-breakout.md) - [Adafruit HUSB238 USB Type C Power Delivery Breakout](https://learn.adafruit.com/adafruit-husb238-usb-type-c-power-delivery-breakout.md) - [A REST API for Arduino & the CC3000 WiFi Chip](https://learn.adafruit.com/a-rest-api-for-arduino-and-the-cc3000-wifi-chip.md) - [Light Meter](https://learn.adafruit.com/light-meter.md) - [DIY Robotic Sky Tracking Astrophotography Mount with CircuitPython](https://learn.adafruit.com/diy-robotic-sky-tracking-astrophotography-mount.md) - [Adafruit STEMMA & STEMMA QT](https://learn.adafruit.com/introducing-adafruit-stemma-qt.md) - [Building CircuitPython](https://learn.adafruit.com/building-circuitpython.md) - [Adafruit TSMP96000 IR Receiver Breakout](https://learn.adafruit.com/adafruit-tsmp96000-ir-receiver-breakout.md) - [Adafruit NeoPixel Driver BFF](https://learn.adafruit.com/adafruit-neopixel-driver-bff.md) - [SD Card Performance in CircuitPython](https://learn.adafruit.com/microsd-optimization-circuitpython.md) - [Introducing the Adafruit nRF52840 Feather](https://learn.adafruit.com/introducing-the-adafruit-nrf52840-feather.md) - [Adafruit Music Maker Shield](https://learn.adafruit.com/adafruit-music-maker-shield-vs1053-mp3-wav-wave-ogg-vorbis-player.md) - [Using IFTTT with Adafruit IO to Make an IoT Door Detector](https://learn.adafruit.com/using-ifttt-with-adafruit-io.md)