[ Android ] Bluetooth Oscilloscope

Android Bluetooth Oscilloscope

*This application is tested only with Samsung Galaxy GT-i5700 Spica (rooted Android 2.1 OS, i570EXXJD1 Baseband version).
The transmitter circuit uses Microchip's dsPIC33FJ16GS504 for the analog-to-digital conversion of the input signals on two channels. The processed data on the dsPIC are then transmitted to the phone (for waveform display) via the LMX9838 bluetooth SPP module.

specs/ranges:

• time per division: {5us, 10us, 20us, 50us, 100us, 200us, 500us, 1ms, 2ms, 5ms, 10ms, 20ms, 50ms }
• volt per division: {10mV, 20mV, 50mV, 100mV, 200mV, 500mV, 1V, 2V, GND}
• analog input (depends on external pre-amplifier configuration): {-8V to +8V }

The source codes for the bluetooth communication is based on Bluetooth Chat example from http://developer.android.com. That example contains three java source files. And, I've completely copied the "DeviceListActivity.java", which is used for searching remote bluetooth devices. Then I've modified the "BluetoothChatService.java" to use only the RFCOMM Client functions, and used the well-known UUID "00001101-0000-1000-8000-00805F9B34FB" for the Bluetooth RFCOMM/SPP.
 
For the plotting of waveforms, I'm using SurfaceView object to draw on its canvas. This tutorial found on www.helloandroid.com helps me a lot for this task: "How to use canvas in your android".

The rest of the job mainly involves porting of my previous Python S60 script to JAVA language. It was too painful on my side, because I had to convert a single script file to multiple java + xml source files! Nonetheless, it was a good experience for me on learning the Android SDK (JAVA programming).

Project source codes for Android and dsPIC (with APK and HEX) :
AndroidBluetoothOscilloscope.zip

Electronicslab.ph forum link : Android Bluetooth Oscilloscope

Here are some interesting projects that are also based on the Bluetooth Chat example:
Bluetooth Controlled Model Car
SPRIME

Special thanks to:
Samdroid Forum  for the customized/rooted firmwares for our Spica.
Tipidcp Spica users for sharing their tips and experiences with this android phone.

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#edit (10-15-2010)
Here's now my circuit. Nothing special on it, all are based on existing circuits.

*The dsPIC I have used is most probably NOT the best choice for this project because of the many left unused peripherals (extra pins). But, this is the only part readily available in my bin and it has the fastest ADC (2 x 2MSps) among the chips I have.
*If you prefer to change the input range via the op-amp preamp, the computation is located on the "adc.xmcd" file.
*You can use other SPP bluetooth modules aside from LMX. (accdg to manufacturer, it's already obsolete)

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#edit (9-14-2011)

It's almost a year now, and yet some people are still interested in this project (considered to be obsolete). So I've decided to place the source repository also on Google Code site. You can either Browse or use git to have your own local copy:
if u like the post just say thank u in comment box.

RF based electronics notice board,sms tranmission

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 RF based notice board

Introduction

Single or Multi electronic notice boards with operating distance up to 1000meters using RS485 protocol

Notice boards play a vital role mostly in educational institutions. The events, occasions or any news, which has to be passed to the students, will be written on the notice boards present in every floor in the colleges or schools. The present system is like, a person will be told the news and he has to update this news on all the notice boards present in the college or school. This will be seen mostly during the examination seasons.

The time table or the schedule of the exams has to be given to the students. This will be done by writing the details on the notice boards. But this process consumes a lot time to update the news on all the notice boards and there may be chances that the person responsible may commit some mistakes or he may be absent sometimes. So, this may create disturbances and the entire schedule may be disturbed. To avoid all these, electronic Notice Board have been designed which completely eliminates the manual work.
   Here we are using RS48.  It is an  alternative for RS-232 for long distance. RS-232 only up  to 15m. but in MAX 485 up to 1500m limit. in addition we connect up to 32 devices.                           If your control system needs to receiving and sending data in the same time you must use full duplex transmission mode. It is possible (and in real world this is the most popular case) that control system first sends request message to ROV (e.g. get temperature) and than waits for the response. In this scenario, there is no possibility that control system and ROV sends data in the same time, so half duplex communication is sufficient.  For full duplex communication you need 4 wires, for half duplex only 2 wires. MAX485 is providing half duplex mode. If you need to use full duplex you must use 2 units (or full duplex chip).