DIY FPV Camera Module for Toy Cars: Easy Control

What can a toy-level mini quadrotor FPV camera module be used for?
If you're interested, keep reading!

The toy quadrotor FPV camera module shown in the picture below can be attached to a toy car to create a Wi-Fi video transmission system. This setup allows you to search for miscellaneous items under the couch, bed, or cabinet—essentially turning it into a smartphone-controlled video car.

After testing it with a mobile app, you'll find that the clarity is decent; you can even read text and easily capture images from under the bed. While it claims to be 720p, it does have some noise.

However, after several minutes of use, it tends to overheat significantly.

When you open the module, you'll notice the 4-pin power terminal labeled as out1 and out2. By connecting a wire and using an oscilloscope, you'll find no signal on pin 4, while pin 3 emits a steady stream of high-level TTL UART signals at fixed intervals.

You can decode the signals using the oscilloscope. After trying baud rates of 9600, 19200, and 38400, you'll discover that 19200 is the correct setting.

By adjusting the four channels, you can observe the pattern of changes; it's quite simple to interpret. All four channels show variations in the servo values, allowing you to identify their corresponding positions. The header is 66, and the end frame is marked by 99; the value 00 remains unchanged, possibly indicating a switch state.

This means that by designing a power board and adding an MCU to decode the serial data and output PWM signals, you could control both the servos and electronic speed controllers (ESCs), allowing you to directly control the toy car.

For the motor, you can use a 360-degree mini servo, and both the wheels and chassis can be 3D printed. If you can't find a suitable mini tread, rubber bands could serve as an alternative.

If testing reveals that the wheels are too small or the ground clearance is insufficient, you'll need to redesign them. Currently, the program runs two independent electrodes for forward and backward movement. Without PWM modulation, controlling the speed can be challenging, so adding PWM speed control is essential for better maneuverability.