Signal generator is second must have tool after oscilloscope while working with electronics designs. I don’t have any signal generators, so I decided to make one. This gone be simple AVR controlled signal generator. For controlling I’ve chosen Atmega8 microcontroller as this is simplest one of Atmega’s series microcontrollers. It has 8kB flash memory.
This is initial post of project. I have only designed schematic and PCB board. I’ll be adding project progress in further posts.
Little bit about AVR controlled signal generator.
This is going to be stand alone generator coated in 100x60x35mm metal box, the one I’ve found in my drawer. It will be powered from 9V battery (through 7805 voltage regulator). Controlling will be done with series of buttons on box side. And information will be viewed on 2.x16 LCD screen on top of box.
Simplified design of AVR controlled signal generator
For controlling LCD display I’ll be using 3 wire interface. I described how to connect LCD using three wires. Using only three wires for LCD there are more ATmega8 pins left for other functions – connecting DAC and buttons.
As DAC in my project I’ll be using R-2R resistor leader connected to microcontrollers 8 pins. This allows having 256 signal levels.
AVR controlled signal generator schematic
Buttons
There will be 7 buttons in AVR controlled signal generator. One will be Reset button which will be acting as stop. Start button to start signal generation. Two buttons for selecting signal and its properties (MODE1, MODE2). FREQ button to select signal frequency (ones, tens, hundreds…) and two buttons to increase or decrease values (UP and DOWN).
There will also going to be ISP header for in circuit programming of Atmega8 microcontroller.
Atmega8 will be clocked at maximum 16MHz to reach maximum performance.
To be continued…
hello sir,
i am interested in your site,but please leave projects in compelet document.
I will do this once I finish my project.