Building Telemetry

10 Points

parameters

Instructions

The remote control car project you kicked off in the classes exercise has gone well (congratulations!) and due to a number of recent sponsorship deals there is money in the budget for enhancements.

Part of the budget is being used to provide some telemetry.

To keep the sponsors sweet a panel has been installed on the car to display the sponsors names as it goes round the track.

You will note that the introduction of these fancy new technologies has dramatically reduced the car's battery life.

1. Enable the remote control car to display sponsor names

Implement SetSponsors() to take one or more sponsor names and store them on the car.

Note that the SetSponsors() method's argument is guaranteed to be non-null.

Implement DisplaySponsor() to display the selected sponsor. The first sponsor passed in has a sponsorNum of 0, the second, 1 etc.

var car = RemoteControlCar.Buy();
car.SetSponsors("Exercism", "Walker Industries", "Acme Co.");
var sp2 = car.DisplaySponsor(sponsorNum: 1);
// => "Walker Industries"

2. Get the car's telemetry data

Implement the RemoteControlCar.GetTelemetryData() method.

GetTelemetryData() should make the battery percentage and distance driven in meters available via out parameters.

GetTelemetryData() should return false if the serialNum argument is less than the previously received value. (There is some issue of multiple telemetry nodes being involved). In this case serialNum will be set to the highest previous serialNum and battery percentage and meters driven will both be set to -1. Where the call is successful serialNum remains unchanged.

var car = RemoteControlCar.Buy();
car.Drive();
car.Drive();
int serialNum = 4;
car.GetTelemetryData(ref serialNum, out int batteryPercentage, out int distanceDrivenInMeters);
// => true, 4L, 80, 4

serialNum = 1;
car.GetTelemetryData(ref serialNum, out batteryPercentage, out distanceDrivenInMeters);
// => false, 4L, -1, -1

3. Add functionality so that the telemetry system can get battery usage per meter

Implement the TelemetryClient.GetBatteryUsagePerMeter() method.

This will call RemoteControlCar.GetTelemetryData(). If GetTelemetryData() returns false or the car has not been driven, then this routine should return "no data". If GetTelemetryData() returns true then a message in the following form should be returned "usage-per-meter=BATTERY-USAGE-PER-METER". Where the calculation is (100 - current battery percentage) divided by the distance driven in meters so far.

var car = RemoteControlCar.Buy();
car.Drive();
car.Drive();
var tc = new TelemetryClient(car);
int serialNum = 4;
tc.GetBatteryUsagePerMeter(serialNum);
// => "usage-per-meter=5"

serialNum = 1;
tc.GetBatteryUsagePerMeter(serialNum);
// => "no data"

csharp