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.
Notes:
. 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.
Results:
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.
Conclusion:
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.
