As a user who owns a non-connected car, I want to access some information about my car on my smartphone so that I know about the position of my car and additional information like fuel level, consumption or driving statistics.<\/span><\/p><\/blockquote>\n <\/p>\n As an employee who wants to drive a pool-car, I want to know where the vehicle is parked so that I don\u2019t have to search on different parking spots around the building.<\/span><\/p><\/blockquote>\n <\/p>\n My goal for this project was to build a functional prototype which meets the expectation of at least one requirement. The project can be separated into three components. First part is a Datalogger<\/strong>, second the Cloud Backend Infrastructure<\/strong> and third the User-Interfaces<\/strong>.\u00a0In the following sections I want to go deeper into the single parts:<\/p>\n The datalogger should record signals like latitude, longitude, speed, engine-speed, consumption, odometer and tank level. For that, I adopted an existing solution based on a Raspberry Pi and got it to work with the OBD-II Interface of my car and an external GPS Receiver. The datalogger records the data in 200 ms steps transmits it every 5 seconds to the backend using MQTT and the AWS IoT Framework.<\/p>\n The primary solution is directly connected to the CAN-bus of the car which provides a large bunch of signals including all required signals. During my modification for <\/strong>OBD-II I had to realize that OBD-II does not provide all the required signals.<\/strong> This restricts the implementation of the first user-story slightly but covers still the requirement to show the position of the car, which is also the main feature of the second user story.<\/p>\n Material:<\/strong> Raspberry Pi Model 3 PiCAN2 Board Serial to OBD-II Adapter Cable USB GPS Receiver * USB Power Car Adapter + Cable<\/p>\n How it works:<\/strong> The device uses the AWS IoT SDK to publish the data via MQTT to the AWS IoT Endpoint. It publishes to the following topic\u00a0 The Main Challenge<\/strong> on this was to design an lightweight but extensible architecture. At first, I searched for examples for my use-case. I wanted to know, how others do that. You can find a lot of examples, tutorials and ready-to-deploy solutions for that. The most cloud providers have example stories with car manufactures or automotive suppliers. Two main examples were helpful for me: The AWS Simple Beer Service (SBS) and the AWS Connected Vehicle Solution. The SBS is a simple example with all important components for an infrastructure like that. It was a good starting point, but as I went further, I found out, that the infrastructure, the picture shows, is a little older. For example, the API Gateway between the Kegerator and the Lambda functions is replaced with the AWS IoT Core part (see Simple Beer Service v5<\/a>). Also for the visualization part, there is a better solution for mobile devices like AWS AppSync.<\/p>\n The Connected Vehicle Solution<\/strong><\/a>\u00a0of AWS offers a range of features and various sample services such as location-based marketing, push notifications or driver evaluation. It’s easy to implement because Amazon provides a cloud formation template that I have installed on my AWS account. It worked without any problems.<\/p>\n Unfortunately, AWS provides no documentation about how to get data to this solution. It would have been helpful to know which signals in which format and how often are expected. So a lot of investigation was necessary.<\/p>\n In this way, I found a helpful tool to simulate a car. The AWS IoT Device Simulator is based on the AWS Cloud Infrastructure, can also be deployed with cloud formation template and provides an interface to simulate car rides.<\/p>\n The source code of the Simulator showed me how the data is structured. The disadvantage became obviously, that for every sensor in the vehicle a message is published instead of aggregating the data and send it every x seconds. Because of this and the complex infrastructure, I decided to implement an infrastructure on my own.<\/p>\n Why Amazon Web Services?<\/strong><\/p>\n The Main Requirement for my project was an IoT Cloud Platform. Well-known products are from Google, Microsoft, IBM, and Amazon. Every one of the four has an example and success stories for their IoT Platform with connected vehicles. I decided on Amazon AWS because it is very well documented, I have a basic knowledge of some AWS Services and my colleagues are familiar with this product, so in case I can ask them. It seems for me to be the fastest way to get a result but also a good way to learn a lot about cloud services like IoT Platforms, Serverless Programming, Storage & Database, Infrastructure-, Platform- & Function-as-a-Service, and in deep about AWS.<\/p>\n Set up IoT Infrastructure<\/strong><\/p>\n In the following, I will explain how I set up the IoT Platform for my requirements:<\/p>\n Assign the policy to your newly created thing. After setup of the IoT Infrastructure, we can continue with storage, database, and Lambda functions.<\/p>\n Create S3 Bucket:<\/strong> All incoming messages will be stored on an S3 Bucket, arranged after vehicle identification number and trip. Create one with named connected-vehicle-data-<\/em>eu-west-1<\/em>.<\/p>\n Create DynamoDB\u00a0Tables:<\/strong> The dynamoDB table will show all vehicles with their current state. Create one named\u00a0connectedVehicle-vehicle-snapshot<\/em>\u00a0with vin as<\/em>\u00a0the primary key.<\/p>\n Create Telemetry Lambda Function<\/p>\n Room for Improvement<\/strong><\/p>\n Further Development<\/strong><\/p>\n There are many ideas to extend the dashboard in the app about vehicle information. As we get on the \/vehicle\/trip\/[vin]<\/em> channel a notification on trip start and end, we cloud trigger on this way some analytics on trip ends like a driver safety score or a green score. Looking at the AWS Connected Vehicle Solution there are more ideas for location-based services (geofence, marketing) or predictive maintenance. In addition to the second user story, a web dashboard for the pool-car manager could be possible to monitor all cars.<\/p>\n There are two main user touch points to the vehicle cloud infrastructure. First, I build an iOS App for that. The App shows a Map and a card-slider with all vehicles. The card displays the vehicle identification number and owner of the car. A good starting point for building an app with AWS AppSync is the documentation<\/a>. The section Code Generation for the API was a little bit unclear for me so I will explain it. AWS provides a tool to generate an API Swift code out of your schema file and queries for you. You need two files to generate the code.<\/p>\nDefine a Scope<\/h2>\n
\nIt wasn’t easy to define the scope for this project because there are many ideas to expand it.<\/p>\n\n
The Components<\/h2>\n
Data Logger<\/h3>\n
![\"Material](\"https:\/\/blog.mi.hdm-stuttgart.de\/wp-content\/uploads\/2018\/09\/datalogger-sm.jpg\")
<\/a>connectedVehicle\/telemetry\/[vin]<\/code>\u00a0with a frequency of 5 seconds. The message structure is as followed:<\/p>\n{\n \"UDID\": \"\",\n \"tripId\": \"\",\n \"canSnapshotObject\": {\n \"sensor\": {\n \"value\": 0,\n \"timestamp\": 0\n }\n }\n \"canFrames\": {}\n}<\/pre>\nCloud Backend Infrastructure<\/h3>\n
\n
{\n \"Version\": \"2012-10-17\",\n \"Statement\": [\n {\n \"Effect\": \"Allow\",\n \"Action\": [\n \"iot:Publish\",\n \"iot:Subscribe\",\n \"iot:Connect\",\n \"iot:Receive\"\n ],\n \"Resource\": [\n \"*\"\n ]\n }\n ]\n}<\/pre>\n
\n<\/span><\/li>\nSELECT * FROM 'connectedcar\/telemetry\/#'<\/code><\/li>\n\n
\n
\n
\n
{\n \"Version\": \"2012-10-17\",\n \"Statement\": [\n {\n \"Sid\": \"VisualEditor0\",\n \"Effect\": \"Allow\",\n \"Action\": [\n \"dynamodb:PutItem\",\n \"dynamodb:DescribeTable\",\n \"dynamodb:DeleteItem\",\n \"dynamodb:GetItem\",\n \"dynamodb:Scan\",\n \"dynamodb:Query\",\n \"dynamodb:UpdateItem\"\n ],\n \"Resource\": \"arn:aws:dynamodb:eu-west-1:xxxxxxxxxxx:table\/*\"\n },\n {\n \"Sid\": \"VisualEditor1\",\n \"Effect\": \"Allow\",\n \"Action\": \"dynamodb:ListTables\",\n \"Resource\": \"*\"\n }\n ]\n}\n<\/pre>\n<\/li>\n{\n \"Version\": \"2012-10-17\",\n \"Statement\": [\n {\n \"Sid\": \"VisualEditor0\",\n \"Effect\": \"Allow\",\n \"Action\": \"s3:*\",\n \"Resource\": \"arn:aws:s3:::connected-vehicle-data-eu-west-1\"\n }\n ]\n}\n<\/pre>\n<\/li>\nvar DATA_TABLE = 'connectedVehicle-vehicle-snapshot';\nvar AWS = require(\"aws-sdk\");\nvar ddb = new AWS.DynamoDB();\nvar s3 = new AWS.S3({params: {Bucket: 'connected-vehicle-data-eu-west-1'}});\n\nexports.handler = function(event, context) {\n\n if (event.UDID!==undefined) {\n\n var rTimestamp = new Date().getTime();\n console.log(rTimestamp);\n var params = {\n TableName: DATA_TABLE,\n Item:{\n \"vin\":{\"S\": event.UDID },\n \"lat\":{\"S\": event.canSnapshotObject.hasOwnProperty('lat') ? event.canSnapshotObject.lat.value.toString() : '-' },\n \"long\":{\"S\": event.canSnapshotObject.hasOwnProperty('long') ? event.canSnapshotObject.long.value.toString() : '-' },\n \"range_in_km\":{\"S\": event.canSnapshotObject.hasOwnProperty('range_in_km') ? event.canSnapshotObject.range_in_km.value.toString() : '-' },\n \"tank_level_percentage\":{\"S\": event.canSnapshotObject.hasOwnProperty('tank_level_percentage') ? event.canSnapshotObject.tank_level_percentage.value.toString() : '-' },\n \"canSnapshotObject\":{\"S\": JSON.stringify(event.canSnapshotObject)},\n \"lastUpdated\":{\"N\": rTimestamp.toString() }\n }\n };\n\n ddb.putItem(params, function(err, result) {\n if(err)\n console.log(\"Error in uploading file on dynamodb due to \"+ err)\n else \n console.log(\"File successfully uploaded to dynamodb.\")\n });\n\n var params = {\n Key: event.UDID + '\/' + event.tripId + '\/vehicle-data-' + rTimestamp,\n Body: JSON.stringify(event),\n };\n\n s3.upload(params, function (err, res) { \n if(err)\n console.log(\"Error in uploading file on s3 due to \"+ err)\n else \n console.log(\"File successfully uploaded.\")\n });\n\n } else {\n context.fail(\"JSON input [UDID] not defined.\");\n }\n\n};\n<\/pre>\n<\/li>\n\n
User Interface<\/h2>\n
The App<\/h3>\n
\nAdjusting the scope (see part data logger) affected the App mainly, so I put the focus on the vehicle position. In this way, the main feature of the app is to show the position of the vehicle.<\/p>\n<\/a><\/p>\n