Dear Mrs. /Mr.
We are a company that manufactures traffic light systems. Our RnD department is in the designing process of a traffic light controller (TLC). The basic operational bloc diagram of the system is shown on the following figure:
As you can notice, the system consists of 5 major entities:
- A CPU card, which controls the operation of the whole system
- A Power Supply
- A number of output cards which drive the traffic lights
- A LCD Display
- A keyboard
So, let us explain you the basic operation of this system.
There will be a Windows based GUI on a PC where the technicians will write a traffic light sequence program. This GUI will produce an output file (containing that program and other information as well) and this file will program the CPU of the TLC. This programming would happen via USB, Ethernet, Bluetooth or RS-232 interface. After this, the TLC will be capable of a standalone monitoring of the traffic lights in a junction.
During this standalone operation the user (technician) will have the ability to check the controllers status through the LCD display and perform some actions (tests,etc) using the keyboard.
For these reasons our system needs to run a basic (Linux maybe?) operating system not only for controlling the various peripherals (usb, Ethernet, etc) and the basic operation but also for the interface between the TLC and the user.
Because we have no previous experience on ARM based systems we would like you to propose us which of your available ARM families and architectures would better match with our project.
Thank you in advance