Tutorial 2: Using the Rich UNO R3 onboard hardware
Real Time Clock (RTC): The board has a built-in clock and back-up battery. This is based on a DS1307 high-precision real-time clock module with I2C serial interface, and address of 68h. XOD provides direct support for this type of chip, and nodes and examples are provided for (i) setting the time, (ii) reading the time, and (iii) formating the year, month, day, date, hour, minute and second for processing or display.
Temperature sensor: An LM75 temperature sensor is mounted on the board next to the real time clock (RTC). The microcontroller communicates with it via an I2C interface, at the address 48h. The temperature sensor is internally calibrated and measures to ~0.1 degree C accuracy. The temperature is output as a number that can be operated on or displayed. The LM75a-temp-sensor node can be found in the gst/lm75atempsensor XOD library - and allows simple access to the on-board sensor. Numerical output from the lm75a-temp-sensor node can be reformatted using the format-number node. This allows the user to define the number of significant digits. The output of this node is in string format. This can be fed to a join node, which allows addition of defined text to the string, and this can be sent to the text-lcd-16x2-i2c node.