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  • SHT75 Humidity and Temperature Sensor with PIC18F uC

    SHT75 from Sensiron is a fully calibrated (calibration constants are programmed individually to each sensor) digital output sensor. It has a I2C like (not compatible with I2C) interface. The sensors are really accurate. I have noticed three sensors close to each other giving an output only deviating by 0.1C of each other.

    The attached source code is derived from an application note provided by Sensiron for interfacing SHT7X sensors to 8051 microcontrollers. Please note this code has temperature/humidity conversion coefficients for older (prior to V4) SHT75 sensors. If you use a newer V4 sensor update the conversion coefficients. The code was written for a PIC18F4580 IC and was compiled with HI-TECH PIC18 compiler.

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  • Interrupt Driven 8-Digit Rotary Encoder Counter

    This example C code can be used to implement a completely interrupt driven rotary encoder counter (incremental type)  using PIC16FXXX microcontrollers built-in timers and counters. This code was written in 2005 for a simple factory automation project I did. The code is written for HI-TECH PIC16 compilers. The microcontroller used was PIC16F877A. Note: This program supports only uni-directional counting. The encoder output should is connected to TMR1 module’s input pin (PORTC1).

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  • Experiments with Oscillator Design

    The following content is from a very old report of a practical assignment I had to do when I was in my 2nd undergraduate year. It can contain a lot of errors. But here it is copied because information in this report might be helpful to students who just start learning about practical oscillator circuits in Electronics subjects.

    This report has some figures/text directly taken from IC manufacturer datasheets and also from application notes provided with these ICs.

    All the simulations were done using Electronics Workbench V5


    In the following experiments I implemented various oscillators and observed their characteristics. My focus was basically on sine wave generation techniques with TL084 QUAD OP-AMP IC and square wave generation using popular 555 IC.

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  • Lenovo Z370 Dead Display

    Just after 3 weeks of use my brand new Lenovo Ideapad Z370 with Intel core i5-2410 with 8GB of Ram started giving me display problems and blue screens. This happened several […]

  • Interfacing TMP101 Temperature Sensor with PIC18

    According to Texas Instrument, TMP101 is a two-wire, serial output temperature sensor available in SOT23-6 package. Requiring no external components, the  TMP101 is capable of reading temperatures with a resolution of 0.0625°C.
    This is from a project I did in 2008. The given routines measure temperature from TMP101 and output it to the serial port of the microcontroller at one second interval. TMP101 was connected to the standard I2C pins of the PIC18F452 microcontroller used.

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  • Simple Encryption Test with PIC microcontrollers

    Way back in 2007 I I had to implement an encryption technique for PIC microcontroller based communication link via RS232. After some tests I found out Alexander Pukall’s PC1 encryption algorithm […]

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