Arduino Clock with control from Android phone

It is some time since I played around with Arduino. My daughter wanted me to show her something other than blinking some LED's. So I promised to build something for her which she could control from her Samsung Galaxy Tab2.

I quickly put together an Arduino, small bredboard shield, 4digit 7-segment display, DS1307 RTC chip and made it up & running. See below the clock working...

Schematic is given below

Arduino IR Transmitter / Receiver

This is based on the work by Ken Shirriff  @ http://arcfn.com

Circuit

I used a proto shield PCB to solder all the components


I modified the original sketch so that I can send the code from PC through a small application. This is my experiment to control Home appliances from PC.

Arduino + Bluetooth Module

My experiment with Aruduino + Bluetooth. Ordered Bluetooth module at ebay (approx $8). Got it in 8days. Had issues in making it work. First tried making connection in bread board and found soldering wires in the bluetooth module will be difficult. So took a small general purpose PCB and soldered few components.

Arduino working at 5V so for TX (arduino) to RX (Bluetooth) put 1K8 + 3K3 resistor voltage divider. For RX I just put 200R resistor in serial.

Two LEDs connected to PIO8 & PIO9 through 1K resistor to show activity & pairing status. Put Arduino Standard Firmata fw. Set baud rate 38400 in Firmata thinking bluetooth module default baud rate is 38400 (this is what I got from the bluetooth module PDF file).

Tried connecting from my Samsung Galaxy SII using Arduino Commander app. No response. Ultimately need to use scope to find out that bluetooth module default baud rate is 9600. Once I changed to this baud rate in Standard Firmata fw, I could connect to Arduino and communicate.

What is further? - Going to make this as IR transmitter to control TV etc