Hi, this is Wayne again with a topic “Making Fun With Jeff Highsmith: Hack A Toy Racer”.
The microchargers line of cars uses pocket-sized launchers to store charge and then launch tiny race cars. Looking inside the car, we see the probes that make connection with the charger, the capacitor that stores the electricity and the tiny motor that powers the car charge them both up and let them run these cars sure do go fast. Let’S find out how fast i’ve wired up a couple light dependent resistors in a voltage, divider circuit for measurement and timing by an arduino. The arduino will detect the voltage drop. That signifies increased resistance caused by the car blocking light as it passes over each resistor.
We’Ll glue the light sensors under the ends of the bank turn the cars don’t steer themselves. They just follow the guard rail and mostly stay to the outside of the turn we’ll measure the distance between the sensors after installing them to calculate the scaled speed, we’ll measure how long it takes the car to travel a known distance in order to scale the speed We need to know the scale of the car if this is a model of a toyota prius, the scale factor is 168.. We use these seven segment leds to display our scaled speed. There are different methods for scaling speed. The simplest method is to multiply the speed of the toy car by the scale factor. This is the method used to figure the 600 plus miles per hour printed on the car’s packaging, but it didn’t match my perception of the car, so i searched some rc car forms until i found a different method in this method. Time is scaled as well, and the result more closely matches viewing a real car from a distance. We’Ll put this math into the arduino code to make it easy to change the sizes later in case, we decide that our prius is actually an expedition in action.
Our scale, speedometer works great 29 miles per hour, isn’t bad for an electric car with only eight seconds of charging for a toy. It’S really quite fast, maybe a little too fast. I tweak the code to flash the sign when the speed limit is exceeded.
Just like a real speed limit trailer now that we have a speed limit and we know when it’s being broken, how do we enforce it? We’Ll just whip up a police car? I even soldered in a blinking red, led for good measure to automate the dispatch of our police car, we’ll need to enable the arduino to control the launcher. It looks like one servo can control both buttons with the police. Car launcher installed, we’ll do a short charge to send a law abiding citizen by looks good, no chase and finally, let’s put our enforcer to the test by sending a scofflaw his way. The speed limit has been broken, the lights flashing and the motors revving as the capacitor is charged off he goes. The chase is on.
You can run little red skull claw, but you can’t hide from the micro pd now it’s your turn folks fire up your imaginations and see what you can come up with think about different ways to trigger the car launches and different places to send them grab your Tools and start making .