Raspberry Pi WIFI radio controlled rc vehicle – cooling with passive heat sinks

Table of Contents

Chapter 10 – cooling with passive heat sinks

It is important to provide sufficient cooling inside the RaPi car for the Raspberry Pi itself and the L298 H-Bridge. With the live video streaming and the WebIOPi the little Raspberry Pi CPU gets much to do and very hot. When I closed the chassis and no passive heat sinks where installed I had a lot more reaction problems and crashes. I decided to measure the temperature of the Raspberry Pi and noted that the temperature is too high. I had not overclocked the Raspberry Pi’s CPU yet. To solve the temperature problem I bought passive heat sinks to cool down the RaPi and a micro fan to blow out the heat of the chassis. If you want to measure the temperature of your RaPi CPU you can use the following command.

/opt/vc/bin/vcgencmd measure_temp

After four hours without the heat sinks and micro fan the RaPi car had inside a temperature of 64°C. With the heat sinks and the micron fan the temperature reached a high of 44°C after four hours.

Heatsinks:

I bought a kit of three heat sinks via Amazon to cool down the Raspberry Pi microchips.

USB-/Lan-Controller
CPU / GPU
voltage converter

All three heat sinks where delivered with a self-adhesive thermal pad. With the self-adhesive thermal pad it was easy to mount the heat sinks. If you want to overclock your Raspberry Pi you should use heat sinks. The picture shows my heat sinks I bought.

Raspberry PI – remote controlled car with a Raspberry Pi heat sink

With the micro fan it was possible to lower the temperature inside the model and the Raspberry Pi no more crashed when the fan was running without heat sinks. But the heat sinks are very cheap and I wanted to be sure that the Raspberry Pi will never overheated even when the fan stops running.

Raspberry PI – remote controlled car with a Raspberry Pi van

After I mounted the three heat sinks I did a last picture of the inside of my RaPi car. This picture shows on which chips I mounted the heat sinks.

The little chip in the lower left corner is the voltage converter. Be careful that the heat sinks not touch any other electronic part of the Raspberry Pi. This could damage your Raspberry Pi.

Raspberry PI – remote controlled car with a Raspberry Pi heat sink 2

Conclusion:

The heat sinks are worth their money. They protect the Raspberry Pi for dying a heat death and they save you a lot of trouble. The little computer it is very challenging to provide a live stream, the web-interface for controlling the car and the WebIOPi library. The micro fan cools the L298 H-Bridge which gets very hot after 30 minutes driving around. Who wants to overclock the Raspberry Pi with e.g. 900 MHZ should buy heat sinks for the chips. Only with heat sinks it is possible to overclock the Raspberry Pi and not to damage the computer immediately.