Hello! Long time lurker, finally posting.
I've made a number of daughterboards to use with ESP32 dev boards. Now I have a more ambitious project: a flush wall mounted device that has 2 microphones, a speaker, and a bunch of sensors (temp, humidity, pressure, VOC, CO2, PM2.5, light, and LIDAR). I'll use it for home automation voice commands, as an intercom, and for the air quality sensors.
I'll still use an ESP32 dev board, mainly because I want PoE (using a wESP32). I briefly looked at integrating an ESP32, but PoE is just too daunting for now.
For the mics and speaker I'm hoping to use MicroChip's ZL38051 for hard to implement features like beamforming and echo cancellation. I'm a bit worried they won't give me access to the docs/tools needed for the firmware. I guess I need to talk to their sale people. This is a personal project, not commercial, so we'll see how that goes.
The schematic is attached (image and PDF), any feedback would be appreciated!
A couple places where I'm not sure:
I've made a number of daughterboards to use with ESP32 dev boards. Now I have a more ambitious project: a flush wall mounted device that has 2 microphones, a speaker, and a bunch of sensors (temp, humidity, pressure, VOC, CO2, PM2.5, light, and LIDAR). I'll use it for home automation voice commands, as an intercom, and for the air quality sensors.
I'll still use an ESP32 dev board, mainly because I want PoE (using a wESP32). I briefly looked at integrating an ESP32, but PoE is just too daunting for now.
For the mics and speaker I'm hoping to use MicroChip's ZL38051 for hard to implement features like beamforming and echo cancellation. I'm a bit worried they won't give me access to the docs/tools needed for the firmware. I guess I need to talk to their sale people. This is a personal project, not commercial, so we'll see how that goes.
The schematic is attached (image and PDF), any feedback would be appreciated!
A couple places where I'm not sure:
- I have 7 sensors and the audio IC on a single I2C bus. I think all of those have pretty low bandwidth needs. The audio IC firmware is transferred over I2C on boot and that can take ~5 seconds, but after that there shouldn't be much traffic. Do you think it's worth it to split the devices over a second I2C bus?
- I put some 1uF and 4.7uF bypass capacitors based on datasheet recommendations. I have 10uF for the whole board, is that plus the many 0.1uF enough? Should I keep the 1uF and 4.7uF since they don't hurt?
- Is my PoE ESP32 going to handle powering all this stuff?
- The audio IC is ~17mA and the sensors aren't much individually.
- The speaker amp can output a max of 3W of the 5W budget I have on 5V (shared with 3.3V). That's for stereo though, so I guess the max is half that ~1.5W. Also audio is rarely playing (only for beep-boops and intercom) and surely not that loud (speaker is 4W, 8ohm, 84db sensitivity).
- For the LEDs, most often they will be off. I'll use them for animations and indicators. They are RGB and I probably won't turn on all 3 LEDs to max. They say 0.1W, 0.5W max, 24.5mA and there are 28 of them. 0.1W*28=2.8W, seems OK. 0.5W*28=14W, doesn't seem OK! What is the right way to judge this?
Attachments
-
157.1 KB Views: 8
-
143.9 KB Views: 8