Are there any projects of the low-frequency signal generator based on the player - Page 1
Forum section: electronics / testgear

author: MegaVolt
author_rank: Frequent Contributor
timestamp: March 14, 2023, 02:49:46 pm
content: A modern music player operates at frequencies of 384kHz and 32 bits and has a volume control and 2 output channels. This is quite enough for a good analog signal generator with low distortion and noise. It also runs on batteries for a very long time.For example, you can record sound files with different frequencies and by selecting them to receive a signal. And adjusting the volume to get a change in the amplitude of the output.Probably you can take the signal back and show, for example, the spectrum or something else ..Has anyone seen oscillators based on audio ADCs? Is there anything that you can buy cheaply on aliexpress and change the firmware or some other projects?

author: CountChocula
author_rank: Unknown
timestamp: March 14, 2023, 03:18:07 pm
content: I suspect that such a signal generator would be of limited utility, with the possible exception of audio workIt should be pretty easy to implement, though… you could use one of several cheap I2S decoders likethis onein conjunction with some kind of MPU like an Arduino or STM32 and an audio amplifier to output waveforms up to ~45kHz on two channels based on whatever arbitrary data you can either synthesize in software or play back from memory.The problem is that for about the same amount of cost and effort, you can probably put together a respectable signal generator for common waveforms (sine, triangle, square) between, say, 0.1Hz and 1MHz using a dedicated DDS chip like theAD9833and a couple of cheap op amps like the LM318. With slight better parts and design, you could probably stretch it to 10-12MHz. You lose the ability to generate arbitrary waveforms, though.

author: alm
author_rank: Super Contributor
timestamp: March 14, 2023, 06:20:11 pm
content: Sound cards are being used as low frequency signal generators / scopes / spectrum analyzers. Search around for software for that. Restrictions, other than frequency (the sample rate may be high, but how about the analog filtering and output stage?), are limited overload protection, only AC coupling and limited amplitude range.They are most useful for what they were designed for: for testing audio devices. SeeRMAA.I'm not sure converting a portable player and writing your own software would be worth it. Maybe if you want to use it as a very limited arbitrary waveform generator.

author: MegaVolt
author_rank: Frequent Contributor
timestamp: March 17, 2023, 08:52:27 am
content: Quote from: CountChocula on March 14, 2023, 03:18:07 pmad9833 Signal-to-Noise Ratio (SNR) 60 dBPlayer Signal-to-Noise Ratio (SNR) 100..120 dBQuoteI understand this.... But I wanted to find a ready solution. Those. buy this box on aliexpress (this box has the best price-quality ratio) and update the firmware))

author: MegaVolt
author_rank: Frequent Contributor
timestamp: March 17, 2023, 08:54:27 am
content: Quote from: alm on March 14, 2023, 06:20:11 pmI'm interested in easy portability and battery life. I understand that there are laptops. But they are big.

author: alm
author_rank: Super Contributor
timestamp: March 17, 2023, 09:44:29 am
content: Use an (old) cellphone. I'm sure there are tone generator apps.

author: MegaVolt
author_rank: Frequent Contributor
timestamp: March 17, 2023, 12:52:38 pm
content: Quote from: alm on March 17, 2023, 09:44:29 amA cell phone does not sound as good as a standalone player. But this is an idea. Thank you