26-07-2012, 03:21 PM
Accelerometer
WORKING IN DETAIL
The first unit in this accelerometer that is capable of detecting the gestures due to change in position. On the change of position the sensor gives the analog variation of the voltage on its x, y and z pins. We convert this analog variation into digital format using Op-Amp As comparator in which we set a threshold voltage (comparison) using preset and the according to the input voltage the voltage is either high or low. LM324 is quad op-amp IC used here. This circuit generates various 4-bit binary sequences on the change of its position. This sequence is transmitted over RF channel.
The transmitter section will be attached to accelerometer circuit which will give parallel binary data as input to the HT12E encoder that encodes the parallel data to serial data. Now this serial data is transmitted over 434Mhz carrier channel using ASK modulation through a short dipole antenna.
The receiver section consist RF receiver which receives the serial data on same carrier frequency and HT12D decodes the serial to the parallel data (as initially was on the transmitter.
The four bit data is input to the microcontroller (AT89S8253-Port1 p1_0 to p1_3)). The controller is responsible for the processing. On the basis of the data received the controller is pre-programmed to display the identity/function on 16x2 LCD.
The programming is done using MIKRO-C compiler using C-logics.
WORKING IN DETAIL
The first unit in this accelerometer that is capable of detecting the gestures due to change in position. On the change of position the sensor gives the analog variation of the voltage on its x, y and z pins. We convert this analog variation into digital format using Op-Amp As comparator in which we set a threshold voltage (comparison) using preset and the according to the input voltage the voltage is either high or low. LM324 is quad op-amp IC used here. This circuit generates various 4-bit binary sequences on the change of its position. This sequence is transmitted over RF channel.
The transmitter section will be attached to accelerometer circuit which will give parallel binary data as input to the HT12E encoder that encodes the parallel data to serial data. Now this serial data is transmitted over 434Mhz carrier channel using ASK modulation through a short dipole antenna.
The receiver section consist RF receiver which receives the serial data on same carrier frequency and HT12D decodes the serial to the parallel data (as initially was on the transmitter.
The four bit data is input to the microcontroller (AT89S8253-Port1 p1_0 to p1_3)). The controller is responsible for the processing. On the basis of the data received the controller is pre-programmed to display the identity/function on 16x2 LCD.
The programming is done using MIKRO-C compiler using C-logics.