Saving your car interior on a hot day - Making a cabin overheating protection system using AutoPi
Studies show that on a hot summer day the temperature inside your vehicle will rise dramatically within just 10 minutes after you parked. HeatKill.org reports that with an outside temperature of 27 C (80 F), the inside temperature could rise to as high as 37 C (99 F) after just 10 minutes. The inside of your car becomes an oven roasting your interior. The sun will permanently damage the color and look of everything it touches, thereby degrading the value of your car.
Did you know?
StateFarm recommends using windscreen sun protectors and seat covers to protect your vehicle.
A number of common advices for protecting your car is:
- Park in the shade
- Use windscreen sun protectors
- Use seat covers
- Open a window slightly
But what if you could build your own system to help keeping temperatures lower inside your car? This is now possible with the AutoPi IoT platform.
What is AutoPi?
AutoPi is a small device that plugs into the OBD-II port of your car.
Once connected, the AutoPi device will automatically start working. It has 4G/3G connectivity, so it is always connected to the Internet. It also comes with a lot of other features, for example continuous GPS tracking. One of the main advantages of the AutoPi is its many extension options.
It comes with an online cloud dashboard, that you can login to from any device. From here you can setup your system and do real-time tracking of your vehicle telematics.
Creating a Cabin Overheating Protection system
By creating a system that automatically lowers the windows in your car slightly, when the temperature gets too high, you can vent out the cabin and make sure the temperature inside is not significantly higher than the outside temperature. This system could automatically ensure that the windows is not opened before a certain temperature is measured, and thereby not letting cold air out of a just parked car.
Since the AutoPi dongle has the possibility to connect external equipment or sensors, it is possible to connect an USB temperature sensor to it. Any sensor will do, but an example is this USB temperature sensors from Yocto. It is very tiny and its location can easily be moved to the best location inside your vehicle.
The temperature sensor is the only external equipment you will need to create your own Cabin Overheating protection system. Once the temperature sensor is connected to the AutoPi, it is easy to install your own software through the module configuration in the AutoPi Dashboard. It is even possible to find existing software modules through the AutoPi Dashboard.
The software modules are configured through your AutoPi Dashboard and when ready they are uploaded and installed automatically to the AutoPi dongle in your car. You can even write your own Python code in the built-in IDE (Integrated Development Environment). The IDE will do basic syntax/code checks before uploading.
When ready, you can set up the system to control the cabin temperature, by opening one or more windows a few centimeters. This will allow the very hot air inside the car to be ventilated out and thereby lowering the inside temperature. You can even setup the system to close your windows again, once the temperature drops to a desired level. Once the system starts ventilating, notifications can be send your phone giving you real-time alerts.
The general idea of the entire system is shown here below. The temperature sensor connects to the AutoPi dongle through USB. The AutoPi dongle controls the vehicle through the OBD port and sends information to the AutoPi cloud dashboard. From the AutoPi cloud dashboard, system status information is passed on to the user, either using alerts like SMS or on the personal dashboard available on all devices.
The AutoPi Core is the system running on the AutoPi Dongle. This system ensures communication between all peripheral units and the AutoPi Cloud Dashboard. The core will collect measurements from the USB thermometer and trigger the OBD connection to the vehicle on the right times, ensuring that the windows are controlled. From the Cloud Dashboard it is possible to setup and configure your system to match your needs.
The flow of the system would be:
- Temperature is measured using the attached sensor. This is picked up by the AutoPi dongle.
- Temperature is checked against rules predefined by the user.
- If the temperature is too high, the window is lowered slightly to allow colder air to get into the car.
- A messages is sent to the user of the car, informing about the preventive measures done by the AutoPi system.
- When the temperature drops inside the car, the window is closed again.
The AutoPi dongle communicates with the vehicle through the built in OBD port. To control the windows, the AutoPi dongle uses the CAN bus in the car to communicate with the ECU inside the car. The system will communicate with the temperature sensor using a serial connection.
We hope this gives you an idea of what you can do with your AutoPi system. Is possible to connect a lot of different sensors and subsystems to your AutoPi and use these to build great things for your vehicle.
Other blog posts for further reading
AutoPi: Using Raspberry Pi as a Parental Control or Teen Driver Mode
Your teenage son or daughter has just received their learners permit and you are worried about them being mature and responsible enough to use your vehicle or maybe you have friends who are irresponsible and terrible drivers. One way to ease your worries is in how AutoPi uses Raspberry Pi to make your car a carputer, basically having a computer within your car, where you can set-up limits and settings in order to control your vehicle in a Teen Driver Mode or as a Parental Control.
Switching from Raspberry Compute to Raspberry Zero
During the design phase of the AutoPi, it was decided to use the Raspberry Compute Module. The Raspberry Compute Module is small, versatile and expandable in a lot of ways, which suited the AutoPi project perfect. All the pinouts from the Broadcom BCM2835 processor is available through the SODIMM DDR2 interface on the Compute Module. This gave us a lot of possibilities during the design phase of the AutoPi and therefore the Compute module was an obvious choice for us as a main processor.