Merge pull request #477 from alexeden/add-adafruit-seesaw

Add adafruit-seesaw driver

Author: BartMassey

README.md

@@ -777,6 +777,7 @@ Otherwise, please add it to the [WIP section](#wip) below.
 
 1. [AD983x] - SPI - AD9833/AD9837 waveform generators / DDS - [Intro blog post][25] - [![crates.io](https://img.shields.io/crates/v/ad983x.svg)](https://crates.io/crates/ad983x)
 1. [adafruit-alphanum4] - I2C - Driver for [Adafruit 14-segment LED Alphanumeric Backpack][29] based on the ht16k33 chip - [![crates.io](https://img.shields.io/crates/v/adafruit-alphanum4.svg)](https://crates.io/crates/adafruit-alphanum4)
+1. [adafruit-seesaw] - I2C - Driver for devices running the [Adafruit Seesaw][75] firmware - [![crates.io](https://img.shields.io/crates/v/adafruit-seesaw.svg)](https://crates.io/crates/adafruit-seesaw)
 1. [ADE791x] - SPI - ADE7912/ADE7913 3-Channel, Isolated, Sigma-Delta ADC - [github][66] - [![crates.io](https://img.shields.io/crates/v/ade791x.svg)](https://crates.io/crates/ade791x)
 1. [ADS1x1x] - I2C - 12/16-bit ADCs like ADS1013, ADS1015, ADS1115, etc. - [Intro blog post][23] - [![crates.io](https://img.shields.io/crates/v/ads1x1x.svg)](https://crates.io/crates/ads1x1x)
 1. [ADXL313] - SPI - 3-axis accelerometer - [![crates.io](https://img.shields.io/crates/v/adxl313.svg)](https://crates.io/crates/adxl313)
@@ -934,9 +935,11 @@ Otherwise, please add it to the [WIP section](#wip) below.
 [72]: https://github.com/FloppyDisck/SHT31-rs
 [73]: https://barretts.club/posts/max6675-hal/
 [74]: https://github.com/rust-dd/embedded-dht-rs
+[75]: https://learn.adafruit.com/adafruit-seesaw-atsamd09-breakout/overview
 
 [AD983x]: https://crates.io/crates/ad983x
 [adafruit-alphanum4]: https://crates.io/crates/adafruit-alphanum4
+[adafruit-seesaw]: https://crates.io/crates/adafruit-seesaw
 [ADE791x]: https://crates.io/crates/ade791x
 [ADS1x1x]: https://crates.io/crates/ads1x1x
 [ADXL313]: https://crates.io/crates/adxl313