Adafruit ADA3657 Adafruit ATSAMD09 Breakout with seesaw

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.

For example, Adafruits ATSAMD09 breakout with seesaw gives you
3 x 12-bit ADC inputs
3 x 8-bit PWM outputs
7 x GPIO with selectable pullup or pulldown
1 x NeoPixel output (up to 63 pixels)
1 x EEPROM with 64 byte of NVM memory (handy for storing small access tokens or MAC addresses)
1 x Interrupt output that can be triggered by any of the accessories
2 x I2C address selection pins
1 x Activity LED

But you can reprogram and reconfigure the chip to have more or less of each peripheral - as long as it fits into the ATSAMD09D14's firmware.
There is a UART converter but it isn't included in the default firmware.

• The ATSAMD09 breakout is great for development of seesaw capabilities.
• You can use it to give your Raspberry Pi or ESP8266 more hardware support.
• Each breakout comes with the assembled and tested board, as well as some header strips.

*Customers looking to resell on eBay or Amazon should contact Adafruit directly.