Circuit diagram for Interfacing SIM300 GSM modem to A89S52

SIM300 is an GSM modem which can be controlled through AT Commands. In this tutorial i am going to explain how to send/receive sms, how to make/receive a call, how to send a tweet to twitter using the SIM300 modem.

I am going to use the sim300 modem with TTL output so it can be directly connected to the microcontroller ports.

Sim300 needs a power supply of 3.4v to 4.5v, but the microcontroller circuit has only 5v supply. I am just using a Diode 1N4007 in series with the Vcc of the modem. So a 0.6v is dropped across the diode and so that the modem will receive only 4.4v.

SIM300 modem used by me.



Circuit Diagram


Just connect the VCC of the modem to +5V through diode and Gnd to microcontroller ground. Then TXD pin to Pin3.0 of the microcontroller and RXD pin to P3.1 of the Microcontroller.

Dont forget you need a minimum 2A power supply, since the GSM modem consume more power at the time of sending and receiving SMS.

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Simple Battery Level Monitor Circuit on Ultimate EC 2013

This simple circuit can monitor the charging process in 12 Volt Lead Acid battery or Tubular battery. The status of LED indicates whether the battery is accepting charge or not. It also indicates the full charge condition.

The circuit can be incorporated in any battery charger like 6 volt, 9 volt, 12 volt etc. The only change needed is replacement of the Zener ZD with appropriate value. That is for 6 volt charger , use 6.1 volt Zener and for 9 volt charger it should be 9.1 volt Zener. 

Battery Level Monitor Circuit

The circuit is based on the switching of two NPN transistors (BC547) to drive the corresponding LED. Zener diode ZD is connected to the base of T1 so as to switch on T1 when the Zener conducts. This happens only when the battery voltage is above 12 volts. Green LED lights when the battery voltage is normal or battery attains full charge. Resistor R1 and Preset VR adjust the base bias of T1 for smooth switching. When T1 conducts, base of T2 will be pulled to ground and T2 turns off and Red LED extinguishes. 

When the circuit is connected to the battery before charging the LED indications will be 

1. If the battery voltage is above 12 volts (that is the normal terminal voltage of 13.8), Zener conducts and Green LED lights and Red LED remains off.
2. If the battery voltage is below 12 volts, Zener remains non conducting and Green LED remains off and Red LED lights.
3. When the battery is connected to the charger, and if the battery is accepting charge, Green LED goes off and Red LED remains on. When the battery attains full charge, Green LED lights and Red LED goes off.
4. If the battery is not accepting charge, Green LED never lights, even after the prolonged charging. This indicates that the battery is not attaining the normal terminal voltage above 12 volts.

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Graphics Text For Facebook Chat and Message By Ultimate EC

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Electronics & Communication Engineering Interview questions With Answers (Part-I)

Electronics & Communication Engineering

 Interview questions With Answers Exclusive 

on Ultimate EC

http://snk.to/f-cu3wdf5k  only 170 kb

(Link Updated)

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Quck Heal TS 2011 10000% workiing Crack by MahammadVasim Khatri Ultimate EC

THIS POST IS WILDCARD ENTRY FOR THIS BLOG
         
[password: Comment Below and Add as Friend  http://www.facebook.com/mahammadvasim.khatri]
                      
     I MahammadVasim Khatri(Wangdu) has developed this software to To fix "Some DLLs ARE MISSING"  after Cracking Quick Heal TS 2011  (x86)

 To use it Just Run File Quick Heal DLL FIXER.exe As Admin   
                  

  
  
Quick Heal Total Security 2011 Crack for 32bit(x86)



Problems Solved
1)Online Registration
2)Automatic Updates
3)PC Tuner Running
4)Fix Some Dll are Missing after Restart


  ::Procedure:: 

1) INSTALL QUICK HEAL TOTAL SECURITY 2011 TRIAL VERSION.
2) Exclude The Folder in Quick Heal (Not to get Delete the files)


   How to do Second Step :

       Run quick heal. Go To Files & Folders Section.

       Select Exclude Files & Folders.

       Click on Add button.
  
       Add the quick heal folder and subfolders to the exclusion list.

       Click on Save Changes button.    



3) START COMPUTER IN SAFE MODE(Pressing F8 at boot menu).

4) COPY ALL THREE FILES FROM "Total Security" FOLDER AND PAST THEM INTO 
   (C:\Program Files\Quick Heal\Quick Heal Total Security) AND REPLACE OLDER ONES.

A)INFORI.dll
B)SCANABT.dll
C)SCANNER.exe
D)Scanres.dll

5) NOW COPY THE FILE PRESENT IN THE "PC Tuner" INTO
  (C:\Program Files\Quick Heal\Quick Heal Total Security\PCTUNER) AND REPLACE OLDER ONES.

        E)PCTRES.dll

6) START PC IN NORMAL MODE.

7) Update Quick Heal 

8)  Disable Quick Heal Self Protection [Most Immportant] 
            
    Run quick heal.
    Go to Settings
    Click on  Self Protection (Confirm that it is OFF) 

9) Now Open Quick Heal DLL FIXER.exe [password:ask at http://www.facebook.com/mahammadvasim.khatri]

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if you find my website useful and helpful for you

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All Copyrights To Ultimate Electronics & Communication @ 2012

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Cellphone-Based Device Control With Voice Acknowledgement

Cellphone-Based Device Control With Voice Acknowledgement

 Govani Hardik

Here is a circuit that lets you operate your home appliances like lights and water pump from your office or any other remote place. So if you forgot to switch off the lights or other appliances while going out, it helps you to turn off the appliance with your cellphone. Your cellphone works as the remote control for your home appliances. You can control the desired appliance by pressing the corresponding key. The system also gives you voice acknowledgement of the appliance status.
Circuit description
Fig.1 shows the circuit for cellphone based device control with voice acknowledgement. It comprises microcontroller AT89C51, DTMF decoder MT8870, voice recording/playback device APR9600 and a few discrete components.

Fig.1: Circuit for cellphone-based device control
with voice acknowledgement

Microcontroller AT89C51 is at the heart of the circuit. It is a low-power, high-performance, 8-bit microcontroller with 4 kB of flash programmable and erasable read-only memory (PEROM) used as on-chip program memory, 128 bytes of RAM used as internal data memory, 32 individually programmable input/output (I/O) lines divided into four 8-bit ports, two 16-bit programmable timers/counters, a five-vector two-level interrupt architecture, on-chip oscillator and clock circuitry. A 11.0592MHz crystal (X<sub>TAL1) is  used to provide basic clock frequency for the microcontroller. Capacitor C3 and resistor R3 form the power-on reset circuit, while push-to-on switch S20 is used for manual reset.

Port pins P1.0 through P1.7 of the microcontroller are configured to get the input from push-to-on switches S1 through S8. Pins of Port P1 are pulled high via resistor network RNW1. Port pins P2.0 through P2.4 are configured to receive the decoded DTMF signal from DTMF receiver MT8870. The functions of the corresponding switches (S1 through S8) and cellphone keys are shown in Table I.</sub>

_{The DTMF decoder is used for decoding the mobile signal. It gets DTMF tone from the mobile headset’s speaker pins and decodes it into 4-bit digital signal. The DTMF decoder is operated with a 3.579MHz crystal (}X_{TAL2 )}  In DTMF receiver MT8870 (IC3), capacitor C12 is used to filter the noise and resistors R6 and R7 help to amplify the input signal using the internal amplifier.

Pin 16 of IC3 connected to resistor R5 provides the early steering output. It goes high immediately when the digital algorithm detects a valid tone pair (signal condition). Any momentary loss of signal condition causes ESt to return to low state.
Pin 17 of IC3 connected to capacitor C11 is bidirectional, acting as steering input/guard time output (St/GT). A  steering logic V_TStdetected at St causes the device to register the detected tone pair. The guard time output resets the external steering time constant, and its state is a function of ESt and the voltage at St.

Port P3 pins P3.6 and P3.7 of IC1 are configured to select the control source for the devices. These are connected to DIP switches S17 and S18 and pulled high via resistors R2 and R1, respectively. Here, we are using two control sources, switches and mobile’s key. DIP switches S17 and S18 select the control sources as shown in Table II.

Pin 2.5 of Port P2 is configured to show the rest status. That is, if none of the control sources is selected by DIP switches S17 and S18, LED1 glows. Resistor R14 limits the current through LED1.

Voice acknowledgement is provided by the APR9600 (IC2). It is a single-chip voice recording and playback device that can record and play multiple messages at random or in sequential mode for 60 seconds. The user can select sample rates with corresponding  quality recording lengths. Microphone amplifier, automatic gain control (AGC) circuits, internal anti aliasing filter, internal output amplifier and message management are some of the features of the APR9600.

Here the APR9600 is configured in random-access mode, which supports two, four and eight messages of fixed durations. The length of each message is the total recording length available divided by the total number of memory segments/tracks enabled.

Audio processor APR9600 can store up to eight voice messages. Port P0 pins and P2.7 are configured to communicate with IC2. Port P0 pins trigger selection of the message. Port pin P2.7 is the input signal to identify whether the voice message is playing or not.

Fig.2: Pin configuration
of mobile headset

Pins P3.0 through P3.5 of Port P3 control the devices with the help of relays RL1 through RL6 via relay driver IC4.

A speaker is connected to IC2 for audio output. The speaker output drives the mic input of the mobile for audio acknowledgement. An electret microphone MIC1 is connected to IC2 to record the voice in IC2. LED2 flashes to show the busy status of IC2 during recording and playback. The audio messages to be recorded in APR9600, by using trigger switches S9 through S16, are shown in Table III. SPST switch S19 is closed for recording and switch S19 is opened for playback.

Fig.3 shows the power supply circuit. The 230V AC mains is stepped down by transformer X1 to deliver the secondary output of 9V, 500 mA. The transformer output is rectified by a full-wave bridge rectifier comprising diodes D1 through D4, filtered by capacitor C16 and then regulated by IC 7806 (IC5). Capacitor C15 bypasses the ripples present in the regulated 6V power supply. LED3 acts as a power-on indicator and resistor R16 limits the current through LED3.

Fig.3: Power supply circuit

An actual-size, single-side PCB for cellphone-based device control with voice acknowledgement is  shown in Fig.4(View as PDF) and its component layout in Fig.5(View as PDF).

Recording and playback 

To record the voice in IC2, follow Table III. Close SPST switch S19 to make pin 27 of IC2 low. Thereafter, press and hold switches S9 through S16 to record corresponding voice messages. LED2 flashes to indicate audio recording.

For playback of any device status, open SPST switch S19 and press the corresponding switch (S9 through S16). The recorded audio can be heard from the speaker connected to pins 14 and 15 of IC2. Fig.2 shows the pin configuration of mobile headset.

Software

The program (Device_Control.BAS) for the microcontroller is written using BASCOM microcontroller programming software. In the program, first, initialise the port (P0-P3) for corresponding controls. Thereafter, declare the variables for the program. After declaration, assign some initial value to variables. Here, microcontroller ports are initialised to make all the devices ‘off’ initially.

After that, the main function checks through ‘Do’ loop which control source has been enabled by using DIP switch pins. If you select switch S17, it searches the input from the mobile only. If you select switch S18, it searches the input from the switches (S1 through S8) only. If you enable both switch S17 and switch S18, it searches the inputs from switches and mobile. Else, the rest-status LED1 glows. Refer to Table II to select the control source.

The mobile signal is decoded into the DTMF signal by IC3. The DTMF output for each mobile key (used in this project) pressed is shown in Table IV.

After getting the input from the switches or mobile, the program goes to the device_action subroutine and executes the corresponding action (refer Table I).

The device_action subroutine changes the status of the device and calls the voice_alert subroutine. The voice_alert subroutine checks the device status and device name from the source input and controls the corresponding pins of IC2. First, it selects the voice signal for the device name. After playing that, it selects on/off status of corresponding device as mentioned in Table III.

If you press ‘*’ key followed by the device number on your mobile handset, it will not change the status of that device and inform the current device status. If you press device number followed by ‘*’ key on your mobile handset, it will change the status of that device and inform the changed device status. ‘#’ key controls the voice_control subroutine and acts like a mute key.

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Getting Started With Atmel Microcontroller : ATMEGA16 : Ultimate EC :~M.Vasim Khatri

Here is a Simple TuToRiAl to learn how to start using atmel microcontrollers  

Will use atmega16 microcontroller in this Tutorial

Here is a link for atmega16 datasheet :

datasheet

Total Nine(9) Presentation Are Give in RAR file:

List of Presentations:

Course contents

1- Introduction.
2-Memories in uc.

3-I/O ports.
4-External and Internal interrupts.

5-Timers.

6-clock sources and sleep modes.

7-reset sources and watch dog timer.

8-communication using SPI or USART.

9-dealing with analog signals.

here is a link for TutoRial Files (presentations)

http://www.mediafire.com/?6pvhggweygges7i

Programs used in this TuTorial are :

1- avr codevision compiler

2-avr studio

3- proteus ISIS for simulation

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