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ARDUINO FREQUENCY COUNTER FOR ANDROID

The Android app is made using MIT App Inventor which is an easy way to make Android apps. http://appinventor.mit.edu/explore/ . The app has
buttons to connect and disconnect the Bluetooth to the phone and 2 displays of voltage and frequency. The .apk file is the file that installs
manually the app to your phone. The .aia file can be imported after you install the MIT App Inventor.
The Arduino generates an accurate 1 second time base for the counter by cascading timer0 and timer2. The link between digital inputs 3 and 4 connects the output of timer2, 250 Hz, to input of timer0. The software waits for the output of timer0 to go positive to start the count of frequency input to timer1. Timer1 is a 16 bits timer, it overflows at the count of 32768, that in turn advances overFlow register. At the end of the 1 second the 16 bit register is recorded. The Arduino then sends to the Bluetooth 5 bytes of data in serial RS232 protocol.
HC-05 is pre-set to code 1234 and name HC-05. The serial RS232 is pre-set to 9600,n,8,1.

ARDUINO CONTROLED BY ANDROID DEVICE VIA USB

The Android app is made using MIT App Inventor which is an easy way to make Android apps. http://appinventor.mit.edu/explore/ .
The Arduino is connected to the Android device using OTG cable, the device also powers the Arduino. The communication is transferred in serial protocol. The app has buttons to connect and disconnect the USB to the phone. There are also 3 LEDS that indicate the Arduino inputs state and 4 tick boxes to control the outputs of the Arduino.
The .apk file is the file that installs manually the app to your device. If you wish to change the app the .aia file can be imported after you install the MIT App Inventor.

ARDUINO WIRELESS REMOTE FOR ANDROID

The Android app is written in BASIC!  http://mougino.free.fr/rfo-basic/index.html#QuickAPK . The app has
connects the Bluetooth. The .apk file is the file that installs manually the app to your phone. The .bas file can be imported after you install the RFO BASIC app to your PC and or your Arduino device.
The Arduino sends via the Bluetoth serial value representing the switch that was pressed. The BASIC! app on the Android phone does these operations.
 switch    5. Starts the Camera
              6. Starts Calculator
              7. Starts the browser and logs to this website
              8. Starts gmail
To change the action of the switches in BASIC!  it requires to enter the Activity Package and class of the app.

PIC16F690 FREQUENCY COUNTER FOR ANDROID

This project is for the Android app and HC-05 as above. The PIC counts the frequency over 1 second period generated by CCP1 and Timer1. Input is counted by Timer0 that can count up to 4 MHz. After each count period 2 bytes of ADC and 3 bytes of the counter are transmitted to the HC-05 Bluetooth module.


You are free to use the circuit diagram and the software with no limitations.

 

The Android app

 

Circuit Description
See also Technical Tips

1K resistor is for reducing 5V to 3.3V input of the Bluetooth module.
HC-05 module can be any make that is powered by 5V, from ebay.
The Arduino can be powered by the android device using OTG cable.

Circuit Description
See also Technical Tips

1K resistor is for reducing 5V to 3.3V input of the Bluetooth module.
HC-05 module can be any make that is powered by 5V, from ebay.