For adding the FEZ NETMF Panda with what happens to sensitive timing processes are handled, I have a first pilot project conceived and realized with some components that I already had in place.
The pilot project includes:
. LCD interface with an HD44780 connected via a I2c port expander (PCF8574), the timing is provided by the driver.
. RFID reader connected via a COM port, the ‘key’ value and time of measurement on the LCD display.
. 2 x SRF05 ultrasonic distance sensor, for connection only need one pin for both outgoing and incoming start pulse pulse result. The measured value is displayed on the screen.
. 2 x SERVO where the measured value of the distance sensor is used for the servo position.
. 8 x LED connected via an I2C port expander (PCF8574) on which a 'night rider pattern is displayed.
. as additional flashes onBoardLED
All this without any appreciable effect on other processes.
. For controlling the LCD, the “Bansky” of driver which you can download for free (http://bansky.net/blog).
. Special attention to the I2Cbus, both port expanders are governed by different processes while only one I2C bus.
. The two ultrasonic distance sensors are in turn controlled because they both use the same ultrasonic frequency and interfere with each other.
All functions work as designed, there are still some requirements:
. A Tristate-Port can not generate interrupt.
. SetPuls the function has no auto-repeat.
. Debugging of the program proved very simple.
. Because the processor pin 5 volt resistance was connecting the components no problem, I had more problems are expected.
This project is successful and is a start for me next “project”
If the work to be completed this week Fezzer.com website I will upload the pilot project there.