# Public addressing system
## Description
Welcome to your new project. Imagine what you can build here.
## Project Details
- **Owner:** aadhishekhar
- **Created:** 3/21/2026
- **Last Updated:** 3/21/2026
- **Visibility:** Public
## Key Components
### J1 — [967](https://www.flux.ai/cherepanyadima/967~d6.md)
- Package: Battery Snap
- Role: Battery Input
- Part Type: Connectors
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p36.pdf
- Manufacturer Part Number: 967
- Role Details: 9V battery clip providing +9V and ground to the circuit
- Manufacturer Name: Keystone Electronics
**Pins:**
- NEG [pin NEG]
- POS [pin POS]
### J2 — [Pin Header 01x05 2.54mm Vertical](https://www.flux.ai/adrian95/pin-header-01x05-254mm-vertical~cas.md)
- Role: Bluetooth Audio Module
- Package: PinHeader_1x05_2.54mm
- Pin 1: +5V
- License: https://creativecommons.org/licenses/by/4.0/
- Role Details: Represents MH-M18 type Bluetooth audio module pins: +5V, GND, L audio output, audio ground, and optional right output
- Pin 5: R_OUT Optional
- Pin 4: Audio GND
- Pin 2: GND
- Part Type: Connector
- Pin 3: Audio Input
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
- 4 [pin 4]
- 5 [pin 5]
### SPK1 — [CMS-18138A-SP](https://www.flux.ai/adrian95/cms-18138a-sp~ldj.md)
- Role: Speaker Output
- Manufacturer Part Number: CMS-18138A-SP
- Datasheet URL: https://www.cuidevices.com/product/resource/cms-18138a-sp.pdf
- Part Type: Speaker
- License: https://creativecommons.org/licenses/by/4.0/
- Package or Case Code: CUI_CMS-18138A-SP
- Package: Speaker
- Manufacturer Name: Same Sky (Formerly CUI Devices)
- Role Details: 8 ohm speaker connected to LM386 output through output coupling capacitor
**Pins:**
- ~ [pin N]
- ~ [pin P]
### U1 — [LM386N-1/NOPB](https://www.flux.ai/adrian95/lm386n-1nopb~d3x.md)
- Part Type: Integrated Circuit
- Role: Audio Amplifier
- Manufacturer Part Number: LM386N-1/NOPB
- Role Details: Amplifies Bluetooth audio input to drive 8 ohm speaker from 9V supply
- Datasheet URL: https://www.ti.com/general/docs/suppproductinfo.tsp?distId=10&gotoUrl=http%253A%252F%252Fwww.ti.com%252Flit%252Fgpn%252Flm386
- Package: DIP-8
- Manufacturer Name: Texas Instruments
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- -INPUT [pin 2]
- +INPUT [pin 3]
- BYPASS [pin 7]
- GAIN_1 [pin 1]
- GAIN_2 [pin 8]
- GND [pin 4]
- VOUT [pin 5]
- VS [pin 6]
### U2 — [L7805CV](https://www.flux.ai/adrian95/l7805cv~q03.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Role Details: Regulates 9V battery input down to 5V for Bluetooth audio receiver module
- Part Type: Integrated Circuit
- Package: TO-220-3
- Manufacturer Part Number: L7805CV
- Role: Voltage Regulator
- Datasheet URL: https://datasheet.octopart.com/L7805CV-STMicroelectronics-datasheet-5316848.pdf
- Manufacturer Name: STMicroelectronics
**Pins:**
- GND [pin 2]
- IN [pin 1]
- OUT [pin 3]
*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/aadhishekhar/public-addressing-system~m9](https://www.flux.ai/aadhishekhar/public-addressing-system~m9).*
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*Generated from [https://www.flux.ai/aadhishekhar/public-addressing-system~m9](https://www.flux.ai/aadhishekhar/public-addressing-system~m9)*