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AVR controlled signal generator-skeleton board

This is continuing of thread AVR controlled signal generator. In earlier post 1 layer PCB prototype, I described a little about making this small project’s PCB. Now a few words about soldering and making the first test run. >This is my PCB board’s bottom. During soldering, I discovered one mistake – ISP headers pin MISO and MOSI were swapped. So I had to do some fixes (the green wire). Another small problem I discovered was that I couldn’t find 20k SMD resistors for my R-2R leader. For this DAC R-2R leader, I need 10k and 20k resistors to make DAC work properly. So I decided to make “fun” with my Board and soldered 10k SMD resistors in series to gain 20k:

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AVR controlled signal generator design considerations

A signal generator is a 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 is gone be a simple AVR-controlled signal generator. I’ve chosen the Atmega8 microcontroller as this is the simplest one of Atmega’s series microcontrollers. It has 8kB flash memory. This is an initial post of the project. I have only designed a schematic and PCB board. I’ll be adding project progress in further posts. A little bit about AVR controlled signal generator. This is going to be a stand-alone generator coated in a 100x60x35mm metal box, the one I’ve found in my drawer. It will be powered by a 9V battery (through a 7805 voltage regulator). Controlling will be done with a series of buttons on the box side. And the information will be viewed on the 2×16 LCD screen on top of the box.

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