Simple Embedded Solutions

PIC16F877A sleep and wake up using external Interrupt: This example shows how to use the sleep function.  When the button is pushed, the processor goes into sleep mode.  When the button is released, the processor wakes up and continues counting. This code was written and compiled in CCS C compiler. Coding : Main code ISR CODE Circuit Diagram : Figure 1 : PIC16F877A Sleep mode                                                                                                                                                                   ...

Temperature sensor (LM35) and Fan speed Controller using PIC16F877A: This post provides a simple digital Temperature meter  circuit  using PIC16f877A microcontroller. This code is written in C language using MPLAB X IDE with XC8 compiler.  In this post, it is assumed that you know, How to use PWM in PIC16F877A microcontroller.  How to interface LCD with PIC16F877A microcontroller. Circuit : Figure 1: PIC16F877A based Fan speed Controller and Temperature meter Code : Figure 2 :Mikroc code for Fan controller Downloads: coming soon...

Difference between PIC16F I/O and PIC18F I/O:  PIC 16F Microcontrollers  have two registers to control IO pins, which are TRIS and PORT. TRIS is used to control direction (Input or Output) of each IO pin while PORT is used to Write or Read data from IO pins. Whereas in 18F PIC Microcontrollers there is an additional register,  LAT . LAT stands for Port Latch. As in 16F, 18F also uses TRIS register to control direction of each IO pin.  LAT  register is used to write  Output  and  PORT  register is used read  Inputs . Writing Bit by Bit : TRISC.F0 =1;    // makes 0th bit of PORTC Input TRISC.F1 =0;   // makes 1st  bit of PORTC Output PORTB.F3 =1; // Makes 3rd bit of PORTB at Logic High PORTB.F7 =0; // Makes 7th bit of PORTB at Logic Low   Mikro C Code for Interfacing Switch : Figure1: Mikro C code Simulation : Figure 2 : Switch Interface with PIC18F4550    ...

7805 Regulator Board design files : Figure 1: 7805 regulator power supply PCB 3D View Figure 2 : 7805 Regulator PCB Downloads: For design file  downloads please  Click Here  to download

What is a Charge Controller ? A solar charge controller regulates the voltage and current coming from your solar panels which is placed between a solar panel and a battery .It is used to maintain the proper charging voltage on the batteries. As the input voltage from the solar panel rises, the charge controller regulates the charge to the batteries preventing any over charging. Types of Charge controller : 1.ON OFF 2. PWM 3. MPPT The most basic charge controller(ON/OFF type) simply monitors the battery voltage and opens the circuit, stopping the charging, when the battery voltage rises to a certain level. Among the 3 charge controllers MPPT have highest efficiency but it is costly and need complex circuits and algorithm. What is PWM: Pulse Width Modulation (PWM) is the most effective means to achieve constant voltage battery charging by adjusting the duty ratio of the switches ( MOSFET ). In PWM charge controller, the current from the solar panel tapers accord...