Digital Clock With Automatic Rotation of LED Display

This project is about a digital clock with automatic rotation of 7-Seg LED display.

This clock can be rotated in any position keeping the digits readable even upside down or in a mirror image!!

It is controlled by an Arduino and driven by accelerometers to find out the correct position in 3D coordinates.

Additionaly there is a feature to show the indoor ambient temperature in Celsius or in Fahrenheit degrees.

The assemble is very simple and I hope you have fun using it !!

Cheers,

LAGSILVA

1. Arduino Uno R3
2. MPU-6050 breakout
3. Multi Funtion Shield for Arduino
4. Female jumper wires

- MPU-6050 breakout:

The MPU-6050 breakout consists in a triple axis accelerometer and gyroscope plus a temperature sensor with following specifications:

• Chip: MPU-6050
• Input Voltage: 3-5V
• ADC: 16 bits
• I/O: standard I2C
• Gyroscope full-scale range: ±250, 500, 1000, 2000°/s
• Accelerometer full-scale range: ±2, ±4, ±8, ±16g
• Temperature sensor range: -40 to +85 ºC

- Multi Function Shield (MFD):

The MFD can simplify and speed up the prototype development.

Main features:

• 4 digit 7-segment LED display module driven by two serial 74HC595's
• 4 x surface mount LED's in a parallel configuration
• 10K adjustable precision potentiometer
• 3 x independent push buttons
• Piezo buzzer
• DS18B20 temperature sensor interface
• LM35 temperature sensor interface
• Infrared receiver interface
• Serial interface header for convenient connection to serial modules such as Bluetooth, wireless interface, voice module, a voice recognition module, etc.

The assembly is very simple and does not need any schematics:

1. Insert the Multi Shield into the Arduino.
2. Fasten the MPU-6050 breakout on the Arduino board using a tiny screw.

There only 04 jumper wires to be connected:

• Red wire: Vcc (+5V)
• Black wire: Gnd
• Green wire: SCL of MPU-6050 breakout to port #6 in the Multi Shield.
• Yellow wire: SDA of MPU-6050 breakout to port #5 in the Multi Shield.

There are 3 buttons to setup the clock:

1. Left button: Press to adjust the hours. Quickly press to set up step by step. Continuous press to advance the hours quickly.
2. Center button: Set the minutes. Continuous press to advance the hours quickly.
3. Right button: a quick press to move for temperature mode.

Note: In Temperature Mode is possible to change the status to Fahrenheit or Celsius pressing the Left button.

The main functions of the code are:

• Reading of accelerometers inclination angles.
• Calculation of the transfer function for the 7-seg LED display (see pictures).

With the angles is possible to detect the spacial position of the clock and decide what routine will be released:

1. Front View - Clock Stand Up
2. Front View - Clock Upside Down
3. Mirror View - Clock Stand Up
4. Mirror View - Clock Upside Down