this page first!
here and extract it in
All libraries were successfully tested (there were some glitches). The only thing which is missing, is a library for 7 segment digits. I will attach it lather and update the archive.
Now, we will test the libraries with some examples and one of the targets is to restore (or to make something similar or better) the original example which come with the board (you know, displaying the time, temperature and the codes received via infrared sensor on LCD).
Another target is to create a complete and user friendly logging application, with SD-Card, start/stop buttons, card eject button, LED indicators, logging temperature, voltage, and current time.
... what pins (again, look at the pinout from the page linked in "Forewords chapter") you must avoid when you design your application:
- [Digital o] - this is a free pin used by the bootloader to signal (using a LED connected to this pin) when firmware is in boot mode and it is flashing when a program is uploaded to the chip.
- [Digital 8, 9] - these two pins are physically connected to USB-to-serial converter, FTDI - you can use them only if you don't use USB communication.
- [Digital 16, 17] - these two pins are physically connected to EEPROM and PCF8583 RTC - can't use them in applications, only if is about an I2C device (and, in this case you must know that I2C addresses from 0xA0 to 0xA3 are used by the above devices).
- [Digital 2] - this is a free pin, assigned by me to One_wire library. Can be on any free digital input pin.
- [Digital 3] - this is a free pin used by the Infrared library as an emitting infrared diode, so be aware of it when you use the library (even if you use only reception and, in this case, if you need to use it, you can use it as digital output pin)
- [Digital 13] - this is a free pin and is used by many applications as a signal LED. It is also used for "Hello World!" blink example.
- [Digital 4, 5, 6, 7] - these are free pins, assigned to SPI microcontroller peripheral and the only SPI device we have on board is the SD Card connector. Reserve them for that if you don't need them in your application.
- [Digital 22, 23, 24, 25, 26, 27] - these are free pins and I reserved them for use with the LCD display
... the 5 push-buttons from the board are connected to the ground and don't have 10K pull-up resistors. The solution is to use as is stated on Arduino site:
"The analog pins also have pullup resistors, which work identically to pullup resistors on the digital pins. They are enabled by issuing a command such as
digitalWrite(A0, HIGH); // set pullup on analog pin 0
while the pin is an input."
... lets set the board. Cut the power off (remember, any connection you do on the board, make them always with the power cut off). I propose the following permanent wire connections, not matter what application we we present here (unless we are running out of pins):
Power the board by inserting the USB cable and you are ready to go (at least, for Blink and reading timer examples... for others, you need more connections to make so, maybe is better to not power the board).