Ask Alexa to make a cocktail you want. Recipes are included in PHPoC script.
How System Works
When an user says to Amazon Echo Dot: “Alexa, ask Cocktail Machine to give me cocktail_name”, the following works will be done:

Amazon Echo streams this sentence to Alexa Service
Alexa Service process this sentence based on configuration of Cocktail Custom Skill and then send “cocktail_name” to AWS Lambda function via endpoint of the Lambda function (URL or Amazon Resource Names (ARNs)). This Endpoint has been configure in Custom Skill configuration
Lambda function publish a message which contains cocktail_name to a topic in MQTT broker.
PHPoC (a IoT Hardware platform, which already subscribed the topic) receives this message, It get cocktail_name and control the step motor to make cocktail based on the recipe.
I have an article (Amazon Echo – Control DIY IoT devices) which explains in detail and shows step by step how to use Amazon Echo to control DIY IoT devices.

Every step of this project is almost the same, there are only some difference on interaction model configuration and source code. You can do step by step on that link. I only show the differences in this article.”