43 lines
2.1 KiB
Markdown
43 lines
2.1 KiB
Markdown
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date = "2017-10-16"
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title = "Signal 1 - DIY Audio Signal Generator (Part 1)"
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tags = ["audio", "design", "electronics", "signal-1"]
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description = "This is part 1 in a series of posts showing you how I build a digitally controlled audio signal generator based on the AD9833."
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slug = "signal-1-diy-signal-generator-part-1"
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**Signal 1** is the name for my first _signal generator_ project. The goal for this project
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is to create a device that can output clean sine waves in the 10 Hz - 100 kHz range for testing
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audio equipment.
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This is what I'm looking for:
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* 10 Hz - 100 kHz frequency range sine waves
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* Stereo Line level output (100-600 Ohm output impedance; 2Vpp) to feed directly into an amp
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* Display of frequency and other settings
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* Frequency presets or 'zero' at 1kHz
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* Adjustable amplitude (e.g. volume control; 5mVpp - 2Vpp)
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* Digitally controlled
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Bonus features:
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* Reverse RIAA circuit
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* Frequency sweep
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There are at this point two pieces of hardware I have selected:
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**AD9833 Programmable Waveform Generator** is a nice chip that can more than handle my simple needs. If
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it can go up to a 16Mhz square wave, that'd be great, but not necessary. It's also inexpensive when bought
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from China as a breakout board. I'm not usually a fan of there boards, but to for prototyping they should
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be fine. The AD9833 communicates for SPI, so I'll need a microcontroller to handle that.
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**Arduino Nano**. I was going to go for an onboard ATMega328 and program it directly using
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_Atmel Studio_. However, there's so much good stuff out there for Arduino that I'll start out
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by just plugging in an Arduino Nano and program that. The upside is that it alread contains
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USB/Serial so it's be rather easy to make this devise computer controlled later on. That said,
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for the final build I might op to integrate the Arduino Nano components on my PCB anyway :-)
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For now, I've ordered a few AD9833 breakout boards from China and I'll start working on a block diagram
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of the entire system soon, which you can read about in Part 2 of this series. |