Posts

Simple Doorbell

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I think at present we can't see a house with out a doorbell.And also people use different types of doorbells.Today I'm going to give you a nice and simple doorbell circuit.Here I have used very common IC UM3481.And another thin is we can get different songs This Ic has the ability to generate more than 16 sounds.Normally we can use 1.5V to 3V to run this circuit. Note:  # Do not use more than 3V. # Build this circuit on a PCB. # As S1 switch use push to on switch.

Zero crossing detection with PIC16F877A

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Zero crossing detection is very important, especially in power control circuits employing thyristors. I have come across many people struggling with zero crossing detection with PIC microcontroller and thus they cannot fire triacs or SCRs as required. So, here I have explained a simple method of detecting zero crossing with PIC16F877A, employing only two or three resistors, a bridge rectifier and an optocoupler for the hardware portion of zero cross detection.  The PIC 16F877A detects the zero crossing using the RB0/INT external interrupt function. I have explained how the zero cross is detected and how the PIC acts upon detection, below.   Fig. 1 - Schematic, zero crossing signal and RD0 signals --------------------------------------------------------------------------------------------------------- Here is the code for PIC16F877A: (You can download the source file from https://rapidshare.com/files/604474700/ZeroCrossing.c ) -------------------------------------------------...

Temperature Sensor (MCP9700 + PIC16F877A)

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Here's a temperature sensor (thermometer) circuit that you can easily build. It uses the popular PIC 16F877A microcontroller. The temperature sensor is MCP9700. The MCP9700 outputs an analog voltage corresponding to the temperature. The PIC reads the analog voltage, processes it and displays temperature on the LCD. The temperature range of this circuit is -40'C to +125'C. The methods of processing the output of the MCP9700 can be found in the datasheet: ww1.microchip.com/downloads/en/devicedoc/21942a.pdf  The analog to digital conversion is done by the PIC ADC module. In the code, I've used the mikroC library function for ADC. You can view the library file here: http://www.mikroe.com/download/eng/documents/compilers/mikroc/pro/pic/help/adc_library.htm However, you should have a knowledge of how the ADC module works and how to use it. I had written a tutorial on modalities of operation of the PIC 16F877A ADC. You can find the tutorial here: http://tahmidmc.blogspo...

Temperature Sensor (DS18S20 + PIC16F877A)

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Here's a temperature sensor (thermometer) circuit that you can easily build. It uses the popular PIC 16F877A microcontroller. The temperature sensor is DS18S20. The DS18S20 communicates through the one-wire protocol. The PIC16F877A communicates with the DS18S20 with the one-wire protocol and gets the information for the temperature and displays it on the LCD. The temperature range of this circuit is -55'C to +125'C. The methods of communicating with the DS18S20 and sending/receiving commands, and reading the temperature value,  are all explained in the DS18S20 datasheet ( datasheets.maximintegrated.com/en/ds/DS18S20.pdf ). Here is the code for the PIC16F877A: (You can download the source file from: https://rapidshare.com/files/1817975964/DS18S20PIC16F877A.c ) -------------------------------------------------------------------------------------------------------------- //Programmer: Syed Tahmid Mahbub //Compiler: mikroC PRO for PIC v4.60 //Target PIC: PIC16F877A ----------...

Temperature Sensor (LM35 + PIC16F877A)

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Here's one temperature sensor (thermometer) circuit that you can easily build. It uses the popular PIC 16F877A microcontroller. The temperature sensor is LM35. The LM35 outputs an analog voltage proportional to the temperature. The output from the LM35 is 0.1V/'C. So, when temperature sensed is 61'C, the output voltage is 0.61V. This analog voltage is read by the PIC and processed to display the corresponding temperature value on the LCD. The temperature range for this circuit is 0'C to 150'C. The analog to digital conversion is done by the PIC ADC module. In the code, I've used the mikroC library function for ADC. You can view the library file here: http://www.mikroe.com/download/eng/documents/compilers/mikroc/pro/pic/help/adc_library.htm However, you should have a knowledge of how the ADC module works and how to use it. I had written a tutorial on modalities of operation of the PIC 16F877A ADC. You can find the tutorial here: http://tahmidmc.blogspot.com/2012/...

MAGIC of knowledge

I turned the switch on and BOOM! That noise, the tiny puff of smoke and the accompanying smell had become far too familiar. I looked on in confusion at all the failed electronics components in front of me. I needed answers. Why did the H-bridge circuit not work as “claimed”? Books showed numerous such circuits. The Internet was not short of designs either. They were all similar though. I had done my research. I thought I understood the principles and modalities of operation. Then, where did the fault lie? Frustration was creeping in. But I just had to find the fault and fix it. I wanted to make the SMPS based inverter because I could learn so much in a field completely new to me and then use the inverter at home during power cuts. In that one night of experimentation, I had failed repeatedly, damaging 24 IR2110’s and a lot more components. I had applied all I had learned thus far. Success, however, eluded me. After repeated failures, I posted my problem on online electronics forums. Nu...

Smart Sine - Software to generate sine table

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Here is the software Smart Sine, that I created and now use to generate sine tables. It is the improved and more developed version of the software I had previously created with a few more useful features. It is relatively simple to use and gives results quickly as opposed to manually calculating the table. If the software asks for .NET Framework Installation, you can download it from: http://www.microsoft.com/en-us/download/details.aspx?id=17851 or http://www.filehippo.com/download_dotnet_framework_4/ Download the software from : Recommended: https://drive.google.com/file/d/0B4SoPFPRNziHWVdLYVFKeHlsWjQ/view?usp=sharing Alternate link: http://www.4shared.com/zip/L2RbV7Hz/Smart_Sine.html Here are a few screenshots: