Microphone to microcontroller - Page 1
Forum section: electronics / general

author: Lay-Z
author_rank: Newbie
timestamp: December 27, 2022, 10:16:34 am
content: Hi,Im looking for microphone to microcontroller. It is important that the microphone should have automatic gain. Im looking for microphone similar to Gravity__Analog_Sound_Level_Meter_SKU_SEN0232-DFRobot 1 but more cheaper.I found only max9814 and sen-12642 but that microphones has no automating changed ranges.Have you any suggestions?

author: SiliconWizard
author_rank: Super Contributor
timestamp: December 27, 2022, 05:56:20 pm
content: The MAX9814 has an AGC, what more do you need?

author: Faranight
author_rank: Unknown
timestamp: December 28, 2022, 06:18:18 am
content: MAX9814 is noisy as hell. I have bad experience with this IC as I tried it with an electret microphone, and the hissing was almost unbearable at higher gains. I then switched to TLV6742 and got complete and utter silence. No autogain though.

author: Lay-Z
author_rank: Newbie
timestamp: December 28, 2022, 09:23:50 am
content: I would like to build a sound level measuring device, something like thishttps://svantek.com/this allows you to measure ambient noise. I simply mean that I would like to get the dB level from the environment as a result. And I found that i don't need AGC. In my electronic collection found sen 12642. Is possible to use it to solution such this?

author: Kalvin
author_rank: Super Contributor
timestamp: December 28, 2022, 09:37:19 am
content: If you want to measure the ambient noise level, and relate the results to the human physiological perception, you need A-Weighting filter after microphone to emulate human perception of acoustic energy.A-Weighting Filter For Audio Measurements:https://sound-au.com/project17.htm

author: Lay-Z
author_rank: Newbie
timestamp: December 28, 2022, 12:57:29 pm
content: Okey thanks for explain. Could you recommend something, cause i can find nothing :/

author: Brianf
author_rank: Regular Contributor
timestamp: December 28, 2022, 02:57:56 pm
content: Quote from: Lay-Z on December 28, 2022, 12:57:29 pmhttps://www.ebay.co.uk/itm/175523979279I believe that it can be found cheaper on Aliexpress.

author: SiliconWizard
author_rank: Super Contributor
timestamp: December 28, 2022, 08:00:11 pm
content: Quote from: Lay-Z on December 28, 2022, 09:23:50 amIf you want to measure sound level, you absolutely don't want to use any kind of automatic gain. So I don't really get your first post.

author: Lay-Z
author_rank: Newbie
timestamp: December 29, 2022, 07:36:52 am
content: Thanks Brinaf for help.SilconWizard, when I wrote the first one post I thought I need AGC, but later it turned out that I doesnt need it, so in the next post I writed that i dont need AGC. Sorry for the confusion guys

author: bidrohini
author_rank: Regular Contributor
timestamp: December 29, 2022, 02:00:37 pm
content: You can check waveshare's sound sensor:https://www.waveshare.com/sound-sensor.htmIt features a microphone and an Onboard audio power amplifier LM386.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: January 03, 2023, 04:55:14 am
content: Those aluminimum can based electret's are so last century...These days microphones look like some 1 by 2mm SMT part and they directly interface digitally with a microcontroller (maybe I2S or something).I just looked at a random one. The link below is a 3 by 4mm device, so it's a bit bigger then I thought.https://www.cuidevices.com/product/audio/microphones/mems-microphones/cmm-4030dt-26165-trthese things are made by the billions. Every phone has one (or maybe more?) of them.

author: Sacodepatatas
author_rank: Regular Contributor
timestamp: January 04, 2023, 11:23:58 am
content: Quote from: Doctorandus_P on January 03, 2023, 04:55:14 amI prefer those little cans because they are more versatile (you can use them with a MCU throught an ADC, or you just use some analog circuitry for conditioning the signal before processing). If you want to make a level meter, you wouldn't like to lose accuracy when converting a linear value from the ADC to a logarithmic value. Hence a propper conditioning of the analog signal (a programmable/selectable decade-gain amplifier) would keep a good compromise of bit accuracy and measure depth.If you already have a discrete digital signal out of the microphone, then you can't reach such performance.

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 04, 2023, 11:52:56 pm
content: Many of the low-cost MEMS microphones have a relatively poor sensitivity, which can make them unsuitable for measuring sound level if you want to be able to go down to 30-35 dB SPL or below.So sensitivity and frequency response should both be considered before making a choice. MEMS mics with better sensitivity can be very expensive.

author: spostma
author_rank: Regular Contributor
timestamp: January 06, 2023, 10:18:41 pm
content: an inspiring sample project with an ESP32, an I2S microphone and a FFT sound detector:https://iotassistant.io/esp32/smart-door-bell-noise-meter-using-fft-esp32/