This article on DigitalWizard describes how you can easily make a system that shows room temperature in dot matrix 32×16 LED display. The project is based on ATmega8 MCU which is a 28 pin high performance microcontroller from Atmel Corp. Please click here to read more.
Microwave Controller’s User Interface Fig. Microwave Timer using AVR ATmega8 The user interface has the following parts. Output Device: A 16×2 alphanumeric LCD Module is used as the main output device. It can display numbers, alphabets and few symbols. It can show two line and each line can have 16 characters. The backlight enables the text to be visible even in dark. A buzzer beeps when the system receive input from the user and the input is successfully processed. For example if the user presses 10 MIN button to increment timer by 10 min and this is successfully carried out the buzzer beeps. But if the timer is already at the maximum setting (90 minutes) the operation could be carried out, so the buzzer does not beeps. This buzzer also beeps a few time when the food is ready (countdown is finished) Input Device: Input from user is received by a keypad which has seven push buttons. The details of button is given below. Button Function Microwave Selects Microwave mode. Grill Selects Grill mode. 10 MIN Increment timer by 10 minutes. MIN Increment timer by 1 minute. 10 SEC Increment timer by 1 sec. STOP/Clear If the microwave is in on condition, this button turns it off and pauses the timer count down. If you are setting the timer, […]
If you want a live demo of this, please register from the link given below. (Only in Pune) REGISTER NOW! This project can also be implemented using a PIC18F4520 microcontroller. Temperature monitoring have wide application in daily life. In modern day keeping an eye on temperature of places such as server rooms, hospital rooms, warehouses and green houses can help solve many problems. But with the use of normal temperature sensors, someone needs to go to the place in order to view the temperature. But with the development of GSM network, one can easily connect the sensor with GSM network, so that you don’t need to be present near the sensor in order to view the temperature. You can just pick up your cell phone and send a request to your sensor by a text message and in no time you will receive the temperature of the remote place ! The advantage is the you don’t need any kind of "special" device at the receiver end. You can use any cell phone to view the remote temperature. This reduces cost as you already have a cell phone. Other benefit is that the range is not limited. You can be at any place in the world (with mobile coverage of course!), to request temperature data from your room. Fig. SMS Based […]
Detecting colour of an object can be an interesting and useful electronic application. It can be realized using a colour sensor like TCS3200 and a general purpose microcontroller like AVR ATmega32. TCS3200 Colour Light to Frequency Converter Chip Fig. TCS3200 Chip . TCS3200 chip is designed to detect the colour of light incident on it. It has an array of photodiode (a matrix of 8×8, so a total 64 sensors). These photodiodes are covered with three type of filters. Sixteen sensor have RED filter over them thus can measure only the component of red in the incident light. Like wise other sixteen have GREEN filter and sixteen have BLUE filter. As you should know that any visible colour can be broken into three primary colours. So these three type of filtered sensors helps measure the weightage of each of primary colours in incident light. The rest 16 sensors have clear filter. TCS3200 converts the intensity of incident radiation into frequency. The output waveform is a 50% duty cycle square wave. You can use the timer of a MCU to measure period of pulse and thus get the frequency. The output of TCS3200 is available in single line. So you would ask how we get the intensity of RED,GREEN, BLUE and CLEAR channels? Well it has two inputs S2 and […]
One of the most basic autonomous robot you can build is a line following robot(LFR). This type of robot is run over a white surface which has an arbitrary path drawn over it by using back paint. The task of the robot is to run exactly along this painted path. You may note that the surface may also be black(or any other dark colour), in that case the path is a light colour like white. Please watch the following video for a LFR in action. Designing an LFR At minimum our LFR design require the following components. A sensor to detect the line on the surface.(It can be a simple IR Reflectance Sensor or an high end camera!). We will use a simple IR based sensor, it is cheap and easy to build and use. This article describe how to make a line sensor array. A microprocessor to run the code that takes inputs from the sensor and control the motion of robot. We will use a cheap single chip computer called an microcontroller (MCU). A popular family of microcontroller is AVR series from Atmel. A member of the popular family is ATmega8. ATmega8 is chosen because it has just the required amount of resources and is very low cost. The MCU cannot drive the motors (used to actually make […]
A PC keyboard is an old and trusted human machine interface. Most peoples are familiar with it. When a text entry is required it is the best method. If we can interface the PC keyboard with an AVR MCU we can create a whole lot of interesting applications! This tutorial will focus on our easy to use PS2 keyboard library for AVR MCU. Fig. 1 – A PC Keyboard(PS2 Type). The PS2 Keyboard Library for AVR The PS2 Keyboard library for AVR has only two functions one for initializing the library and one for reading a ASCII character from the queue. The keyboard library automatically translates the scan codes to ASCII characters and buffers them in a FIFO queue. That means even if the CPU is busy doing something else and a character arrives from the keyboard, it will be automatically buffered in a queue. After that the CPU can read the characters anytime when it is free. void InitPS2() Function to initialize the PS2 keyboard library. Internally it initialize the ps2 system and sets up the INT0 isr for handling PS data traffic. Arguments: NONE Return Value: NONE char ReadFromKbdQ(uint8_t wait) Function to read a character from the keyboard buffer. The wait parameter can be 0 or non zero. When wait is non zero the the function […]
In this tutorial we will discuss a simple PC controlled robot. The Robot PC link will be a RS232 serial line. The robot will have only five commands. Move forward (RS232 char ‘F’ or ‘f’) Move backward (RS232 char ‘B’ or ‘b’) Turn Left (RS232 char ‘L’ or ‘l’) Turn Right (RS232 char ‘R’ or ‘r’) Stop (RS232 char ‘S’ or ‘s’) To keep things as simple as possible, in this example we will use terminal software RealTerm for sending commands to the robot. Later on a dedicated software can be written on PC end to control the robot. The Robot’s Hardware The robot’s hardware will be a simple differential drive using two 200RPM DC Gear motor mounted on a HQ Metal Chassis with a front castor wheel. On the back motors we have mounted plastic wheels. More about differential drive is explained in this tutorial. Gear Motors Wheels Metal Chassis Remove motor’s nut Insert the motor Fasten the nuts again Both motors installed Front Castor wheel Installing the front castor Mounting hole for wheels screw Mounting the wheels Chassis is ready! The Electronics The robot is controlled using xBoard v2.0 which has ATmega32 as main CPU and integrated motor drivers. We have connected xBoard v2.0 with PC using […]
Many times a nice visualization of ADC data is required during learning about new sensors. In this situation this valuable tool will come to your help. The tool I called is ADCGraph2, it is being with me from a long time but today I thought of sharing it publicly.
Here is a nice and entertaining project created by http://www.ermicro.com . The author has a very good programming, teaching, drawing and artistic skills. The tutorial is well planned and executed. I really liked the RGB LED and Sound show given at the end. I will try it and tell how it works. Till then you can read the rest of the article here. Working with Atmel AVR Microcontroller Basic Pulse Width Modulation (PWM) Peripheral AVR RGB LED and Sound Show. The article also explain various PWM techniques like Fast PWM, Phase correct pwm, phase and frequency correct pwm. You will also learn tone generation using PWM technique. Here is a Video for Various PWM Experiments
Hi Friends, Today I will present an easy to build Multi channel IR Remote control system. It can control heavy loads (Up to AC 220V 6 Amps or smaller) with a touch of remote control. A total of 5 devices can be controlled from a distance of up to 20 feet. We will be using a standard remote control protocol that is called the NEC format. The NEC format is common in remote controls used with Chinese made CD/DVD players. They are easily available in Indian Markets. They also come in variety of sizes from full to small 21 keys (used in car audio systems). Our system is smart enough, so the user can set which key controls which load. Their are five load indicator LEDs which provide the state of five loads. When the device is powered on for the first time, the load LEDs start to blink one by one. That is the first load LED starts to blink, this means the system is waiting for the user to assign a key for that load. So you should press the key you want to use for that load. Once the system receives the key of your choice it stores it in internal EEPROM. From now on you can use that key to control that specific load. In this […]