My capstone group is making an audio loop system and our main components are two esp32’s, a speaker and microphone. We used the code from the “Sound with ESP32- I2S protocol”. The microphone we are using is the same as the project, the INM441 and have that connection working. We are using two ESP32 to communicate to each to send the audio signal from the microphone to the speaker. Theoretically these will be separated throughout the room, one will be with the teacher who is speaking into the microphone and another in a classroom with a hearing impaired student. I will include the schematic for our project for better understanding. We think the problem is between the two esp32s but would appreciate any insight. We originally wanted to use Bluetooth for the esp to output to the speaker but we don’t have a lot of knowledge in this area and couldn’t get that to work. I can upload the code as well if that in necessary. https://buckeyemailosu-my.sharepoint.com/:b:/g/personal/adkins_671_buckeyemail_osu_edu/EVZ-ybOThQNBjWlkiCRLhi8Bf_KXyqWWSQIbPcA6KQ16vw?e=T5Ceay
Sound almost like you are building a one-way "walkie-talkie", is that correct? If so, you might find some inspiration on this design by Atomic14 on GitHub. His design uses ESP-NOW, so I'm not sure what the audio fidelity would be like, as the bandwidth on ESP-NOW is pretty limited.
By "audio loop system" I'm assuming that this is the inductive loop system used with hearing aids. Does it interface to the ESP32 in any way? I don't see any reference to it on the schematic.
😎
Bill
"Never trust a computer you can’t throw out a window." — Steve Wozniak
@natalieadkins As a hearing impaired person this interests me. Can I ask why an iPhone and Apple certified hearing aids is not an option? That has made a huge improvement in my life.
First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.
Interesting project, I looked at something a few years ago however at the time the phone and Bluetooth option had an unpleasant lag. From Ron’s comment sounds like it may be better these days, or perhaps it depends on the quality of your equipment.
I like the idea of transmitting between esp32s using WiFi to get the distance you might need in a larger space, then use Bluetooth or a localised induction loop to transmit to hearing aid. Not sure what the latency will be like.
Are you worried about the speaker disturbing other students?
Looking at the drawing I’m not sure the microphone module is wired up correctly
this is a useful pdf particularly page 8
https://invensense.tdk.com/wp-content/uploads/2015/02/INMP441.pdf
what is it that isn’t working?
@zander Hi Ron! At the beginning of our project we looked into hearing aids and directly pairing the system to an iPhone. We are working on this system for a school project and have time and budget limitations (we don't have access to nor can we afford a hearing aid within our budget). We simplified our system to operate like a simple one-way walkie-talkie and not go through a smartphone. This isn't really meant to be a full-scale project for proper implementation, just a school project. In the future, maybe some future capstone group can pick up on our project and make it more compatible with smartphones.
@dronebot-workshop Hi Bill, we are essentially building the one way walkie talkie like you said and have used parts of that code that you attached. We are having some trouble with this, and don't know where we should start troubleshooting. Also instead of using an actual hearing aid (due to budget and accessibility) we have a speaker/headphone on the receiving end of an esp32 to be a placeholder for a hearing aid.
@tain Hi Tain! We used the schematic given on this website and have been able to test the microphone and get an accurate signal from the transmitting side. We believe the problem is with the speaker on the receiving end, that it is only outputting white noise. How would you recommend we change the schematic and how microphone is connected?