Truthfully, I have always wondered how auto manufacturers did that. What I mean is have a system that is 100% reliable and ready in seconds with the turn of a switch. That is a pretty extraordinary concept in the electronics and software world.
Think of the LCD screen in your car like your LCD TV. Your television takes
a few seconds to boot-up and start working. It's because the electronics
and software is designed for one specific function - to display a video stream.
It has a very fast processor and limited amounts of "code" to go from OFF to
displaying the Football game almost instantly.
Your desktop computer or laptop is a "jack of all trades" and "multi-tasker".
It needs to load a bunch of drivers for the monitor, mouse, keyboard, WIFI,
hard-drive, USB, ports, network controller, etc. , etc.
Then it has to load the operating system, software applications and figure out
how to interpret your human inputs to make something happen on the screen.
On top of that, all of the extra software you download (games, apps, CAD
programs, etc.) take up more space and memory to run which slows things
down further.
Your modern day car has about 10-20 individual, embedded computers
(meaning specific function computers) that do one set of specific tasks.
One computer for to control the motor (PCM), one for airbags (SRS),
one for the infotainment (various), one for the body (BCM), brakes (ABS),
on so forth.
All of these embedded computers boot up SUPER fast - they are more like
controllers. Think of them as appliances in your home. You turn them on
and begin to work immediately as they are responding to electrical signals
instead of data.
They process that information (IE: door switch is open) and send that information
on a network bus (CAN bus is the industry standard) at very fast rates.
Hopefully that paints a decent picture of what's happening when you turn
the key in your car...or should I say, "push a button". Some cars even
begin to boot-up when you open the door or pop the locks!
Hi Tino,
Great to see you are making progress on this build as mine is stuck in the mud, did you use PWM for the heater and AC control? What frequency worked best for you?
Are you still using processing for this stuff?
Thanks,
Mostafa
Hey Mostafa,
Yes I'm using PWM. The typical frequencies are 976.56 Hz and 490.20 Hz
on this controller. I'm pretty sure it's using the default to 490.2 Hz.
Processing is providing all of the graphic interface code and some control
code. The ARDU IDE is handling all of the logic code.