avr

ConnDuino intrefaces to add-on modules

This is the region where add-on devices may be plugged to ConnDuino. Several pin headers exist here, which interface the pinout of some common modules, such as:

  • TFT display screen
  • LCD 16x2 display
  • Radio receiver or transmitter modules
  • Real time clock (RTC) module

The mapping of these pin headers to the Arduino compatible digital or analog pins (in other words the Atmega328p pins), has been designed in such a way that no conflict occurs. This means that all pin headers may be utilized concurrently, to install the respective number of add-on devices, while still some digital and analog pins remain free for other uses!

In this article the details for each installable add-on module are described.

The Arduino in ConnDuino

The article describes the Arduino compatible region of ConnDuino, and its enhancements. Also, the topic of I2C pull-up resistors and their suitable values is discussed.

All the pins of the official Arduino Uno Rev.3 design are available in ConnDuino, in their expected positions. Included are the analog and digital pins as well as the supply and ground pins.

An introduction to ConnDuino

ConnDuino is a custom, Arduino combatible board, based on the Atmega328p microcontroller. It has been conceived and designed as a platform for rapid development of electronics projects. Before going into details, its main features are the following:

  • Pin combatible with Arduino Uno Rev.3 (analog, digital and supply pins).
  • Selectable input voltage (5v or 3.3v).
  • Selectable voltage for the I2C bus (5v or 3.3v).
  • Custom pins for several components to be installed (tft screen, lcd 16x2 display, eeprom, rtc, rf module, etc).
  • Multiple ground and regulated voltage pins for sensors or other devices (5v and 3.3v).
  • Multiple SPI bus pins (4 sets).
  • Multiple I2C bus pins (6 sets).
  • On board voltage ladder for up to six buttons connected to a single analog pin.
  • 8x13 holes as expansion/prototyping area