I bought a “flip toy” rc car at thrift shop for $3. It was originally powered by 4 AAA batteries. The radio is 49mhz, controller has 1, 9v battery.
When I first bought it the range of radio was only about 20 feet. I attached a long spring stretched out on antenna which brought range up to about 100’.
I don’t plan on using the 49mhz controller in the future for this robot but use a pi pico or esp8266 and have it connected to wifi.
I want to make it so it can drive around my house and avoid objects, then when battery is getting low,it will park in a designated spot.
So far I removed plastic car “body”, made a small aluminum frame and mounted a watertight plastic box on top. Using a tp4056, and boost convertor, I eliminated the 4 AAA, and now have it running on 5.5v.
I was having issues with the voltage collapsing when starting off, boost convertor supplies 2 amp max. So I put a 5.5v 1.5f supercapacitor on the boost convertor output, and that seems to have fixed that issue.
I tested and each motor can pull up to 1.8 amps if the car is stalled out then both motors are started at same time. Close to 4 amps for both, which is surprising for such small motors.
I know it would probably be best to add a second LiPo cell in series and run the motors directly from battery.
I was originally planning on using the original control board, just eliminating the existing RF chip that drives the mosfets and connecting my gpio from mcu there. We will see.
Any ideas appreciated!
Original car looked like this:
