[El Artis] just finished building an audio spectrum analyzer that uses a character LCD. The uses an Arduino to drive the display, but unlike other meters that use the microcontroller for analysis, [El Artis] is using a discrete IC for that task.
This project uses the MSGEQ7 graphic equilizer display filter chip to grab frequency data from the audio source. The chip connects to your microcontroller of choice using two digital pins and one analog pin. [El Artis] points us to [J Skoba’s] post about how to use it with an Arduino, then adds his own custom character routines for an HD44780 display. You’ll notice that there are sixteen bars in the image above, which conflicts with the 7 outputs the chip offers. [El Artis] averages neighboring values in order to add the extra outputs.
Don’t miss the demo video after the break. If you’re looking to use this part in one of your projects, we noticed they’re a little hard to find (octopart doesn’t return any suppliers) but SparkFun has them.
Continue reading “Character LCD spectrum analyzer made simple with a dedicated IC”
[Camilo] built a spectrum analyzer to use with his audio system (translate). The hardware is quite simple, using an op-amp, microcontroller and LCD display. He chose an LMV324M low-voltage op-amp which connects to the incoming audio signal and feeds its output to the microcontroller’s ADC. In this case, he chose a Freescale microcontroller from the HCS08 family which is running at 20 MHz. This gives the project enough speed to properly analyze the incoming audio. He mentions that he’s following the guidelines set forth in the Nyquist-Shannon sampling theorem and using the Fast Fourier Transform when processing the samples.
This isn’t the first time we’ve seen a character LCD used as a display for a frequency analyzer. This other ATmega8-based rendition supported several different screen layouts. These displays have enough RAM to store eight custom characters. Each character is 5×8 pixels, lending eight levels to each character for a total of 16 for each column seen above. We love the simplicity of the hardware in the project but we wouldn’t mind seeing an additional potentiometer to fine-tune how the data is displayed on the screen to take advantage of its full range. See the project in action in the clip after the break.
Continue reading “Spectrum analyzer users custom characters on an HD44780 display”
[Fred] dropped a note in our tip line to let us know about arduino forum user [bilbo]’s latest project: A 3-in-one spectrum analyzer, oscilloscope, volt-meter combo. The build consists of an Arduino, radio board and Nokia 5110 LCD breakout board. The (thin) video after the jump shows the rig in action. Though soldered to a full sized perf-board we can see later, smaller, battery powered versions prove useful in rooting out wayward bluetooth signals, or just finding that lost microwave oven. Although [bilbo] uses the same radio board as similar builds his creation boasts several different display modes, as well as doubling as a volt meter and miniature-oscilloscope. There is no shortage of previous spectrum analyzer builds, but this one is the first one we have seen running on an Arduino.
Thanks for the tip [Fred]! If you feel like wedging some frequency scanning capabilities into your next project don’t forget to check out [bilbo]’s forum posts for source code!
Continue reading “Arduino Powered 2.4 GHz Spectrum Analyzer”
This spectrum analyzer project seeks to improve the quality of tools available to amateur radio operators. A lot of thought has gone into the design, and those details are shared in the verbose project log. The case was originally a CATV link transmitter, but most of the controls seen above have been added for this build, with unused holes filled and finished to achieve the clean look.
One noteworthy part of the build is the time that went into building a rather complicated-looking 1013.3 MHz cavity bandpass filter. Despite the effort, the filter didn’t work. Details are a bit sketchy but it seems that some additional tuning brought it within spec to complete that portion of the device.
This certainly makes other toy spectrum analyzers look like… toys.
[Simon Inns] just rolled out his latest project, a PIC based spectrum analyzer. He’s using a Fast Fourier Transform routine crafted in C to run as efficiently as possible on the 8-bit chip. The video after the break shows that the results are quite pleasing, with just a bit of noticeable lag between the sound and the waveform representation on the graphic LCD. We found his notes about using an audio amplifier chip to be interesting. He utilizes the properties of an LM386 to move the input signals from a range of -0.5V to +0.5V into a very ADC friendly range of 0-5V.
Continue reading “PIC spectrum analyzer uses Fast Fourier Transform routine”
A small, cheap spectrum analyzer with an LCD can be a fun thing to play with. But to be truly usefully you need access to raw data, and lots of it. [Travis Goodspeed] set out to make that possible by pulling data with a GoodFET and a Python script.
He started with [Michael Ossmann’s] IM-ME spectrum analyzer, which uses a CC1110 chip. The two of them are giving a lecture at Toorcon 12 (called Real Men Carry Pink Pagers) and this will be used as a demonstration device. After studying the datasheet he found the starting RAM address and did some further work to deciphered how the data is stored in it. From there it was a matter of working out the timing for grabbing the data, and coding a method for storing it. Now he’s looking for brave souls to help him trailblaze with this newly-discovered tool. It seems that if you know what you are doing, and have abundant patience, you can use this for a bit of old-fashioned reverse engineering.
[Michael Ossmann] rolled out some firmware that makes his IM-ME into a Spectrum Analyzer. He met up with [Travis Goodspeed], who authored the IM-ME flashing guide, at SchmooCon and spent some time hacking wireless doo-dads in the hotel bar. Once he arrived home the new firmware was just a few coding sessions away from completion. It scans one frequency at a time, displaying the results in a 132 column graph on the screen. He also added a ribbon cable and header to the debug contacts so that future hacking would be as simple as plugging in the GoodFET.
[Thanks Jared and Travis]