# Rocket Finder

## Description

Compact 11\.7 mm × 30\.5 mm LiPo\-powered outdoor alarm with USB\-C charging, a 120\-second MCU lockout, analog light sensing, and a latched repeating sounder output\.

## Project Details

- **Owner:** roytyson
- **Created:** 9/11/2026
- **Last Updated:** 9/14/2026
- **Visibility:** Public

## Key Components

###  — [ATTINY202\-SSNR](https://flux.ai/adrian95/attiny202-ssnr~et7.md)

- Manufacturer Part Number: ATTINY202\-SSNR
- License: https://creativecommons\.org/licenses/by/4\.0/
- Role: Controller
- Role Details: Firmware enforces a full 120\-second lockout on every power\-up, filters the PA2/AIN2 LIGHT\_SENSE darkness\-to\-outdoor\-light transition with hysteresis, latches the alarm, and drives a repeating beep cadence on PA3/TCA0 WO0 until power is switched off; PA0 is reserved for UPDI\.
- Functional Group: Control
- Manufacturer Name: Microchip
- Datasheet URL: http://ww1\.microchip\.com/downloads/en/DeviceDoc/ATtiny202\-402\-AVR\-MCU\-with\-Core\-Independent\-Peripherals\_and\-picoPower\-40001969A\.pdf
- Part Type: Microcontroller

**Pins:**
- \~RESET\~/PA0 [pin 6]
- GND [pin 8]
- PA1 [pin 4]
- PA2 [pin 5]
- PA3 [pin 7]
- PA6 [pin 2]
- PA7 [pin 3]
- VCC [pin 1]

### BZ1 — SMT\-0927\-S\-HT\-R

- Role: Sounder
- Manufacturer Name: PUI Audio, Inc\.
- Manufacturer Part Number: SMT\-0927\-S\-HT\-R
- Datasheet URL: https://puiaudio\.com/file/specs\-SMT\-0927\-S\-HT\-R\.pdf
- Package or Case Code: XDCR\_SMT\-0927\-S\-HT\-R
- Part Type: Buzzer
- License: https://creativecommons\.org/licenses/by/4\.0/
- Role Details: Provisional externally driven magnetic transducer candidate: 2–5 V0\-p, ≤100 mA, 2\.7 kHz nominal, minimum 95 dBA at 10 cm\. Does not substantiate the \>100 dB at 10 cm product target; acoustic validation/replacement remains open\.
- Functional Group: Alarm Output

**Pins:**
- \~ [pin N]
- \~ [pin P]

### D1 — [SML\-D15UWT86C](https://flux.ai/adrian95/sml-d15uwt86c~ct7.md)

- Role Details: Red LED illuminated whenever switched VSYS power is present
- Functional Group: Battery Power
- Part Type: LED
- Datasheet URL: https://www\.rohm\.com/datasheet?p=SML\-D15UW\(C\)&dist=Digi\-key&media=referral&source=digi\-key\.com&campaign=Digi\-key
- Role: Power Indicator
- Manufacturer Part Number: SML\-D15UWT86C
- Manufacturer Name: Rohm Semiconductor
- License: https://creativecommons\.org/licenses/by/4\.0/

**Pins:**
- A [pin 2]
- K [pin 1]

### D2 — [BAT54WS\-7\-F](https://flux.ai/lcsc/bat54ws-7-f~6dah.md)

- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/lcsc/1806121749\_Diodes\-Incorporated\-BAT54WS\-7\-F\_C124205\.pdf
- Functional Group: Alarm Output
- Manufacturer Part Number: BAT54WS\-7\-F
- Product Info Url: https://lcsc\.com/product\-detail/Schottky\-Barrier\-Diodes\-SBD\_DIODES\_BAT54WS\-7\-F\_BAT54WS\-7\-F\_C124205\.html
- Role: Flyback / Freewheeling
- LCSC Part Number: C124205
- JLCPCB Part Class: Extended Part
- Package or Case Code: SOD\-323\_L1\.8\-W1\.3\-LS2\.5\-RD
- Manufacturer Name: DIODES\(美台\)
- Part Type: Schottky Barrier Diodes \(SBD\)
- Role Details: Schottky recirculation diode across externally driven magnetic sounder; cathode to VSYS, anode to MOSFET drain

**Pins:**
- 1 [pin 1]
- 2 [pin 2]

### J2 — [S2B\-PH\-SM4\-TB\(LF\)\(SN\)](https://flux.ai/adrian95/s2b-ph-sm4-tblfsn~b96.md)

- Role: Battery Connector
- Functional Group: Battery Power
- Manufacturer Name: JST Sales America Inc\.
- Symbol Style: parametric\-v1
- Datasheet URL: https://www\.jst\-mfg\.com/product/pdf/eng/ePH\.pdf
- Manufacturer Part Number: S2B\-PH\-SM4\-TB\(LF\)\(SN\)
- Role Details: 2\-pin side\-entry JST\-PH for protected 1S LiPo; schematic assigns pin 1 BATTERY positive and pin 2 GND\. Verify mating battery lead polarity before connection because JST\-PH battery cable polarity is not universally standardized\.
- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Connector

**Pins:**
- P1 [pin 1]
- P2 [pin 2]

### Q1 — [ALS\-PT19\-315C/L177/TR8](https://flux.ai/adrian95/als-pt19-315cl177tr8~e4b.md)

- Manufacturer Part Number: ALS\-PT19\-315C/L177/TR8
- License: https://creativecommons\.org/licenses/by/4\.0/
- Role: Light Sensor
- Part Type: Phototransistor
- Manufacturer Name: Everlight Electronics Co Ltd
- Datasheet URL: https://www\.mouser\.com/datasheet/2/143/EVER\_S\_A0004523655\_1\-2548694\.pdf
- Functional Group: Light Sensing
- Role Details: Analog outdoor light measurement for firmware thresholding and hysteresis

**Pins:**
- C [pin 1]
- E [pin 2]

### Q2 — [AO3400A](https://flux.ai/adrian95/ao3400a~ug9.md)

- Datasheet URL: https://media\.digikey\.com/pdf/Data%20Sheets/Alpha%20&%20Omega/AO3400A\_ds\.pdf
- Manufacturer Part Number: AO3400A
- Role: Low\-Side Driver
- Manufacturer Name: Alpha & Omega Semiconductor Inc\.
- Functional Group: Alarm Output
- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Transistor
- Role Details: Logic\-level MOSFET switches 100 mA sounder from MCU GPIO

**Pins:**
- D [pin 3]
- G [pin 1]
- S [pin 2]

### SW1 — [SSSS810701](https://flux.ai/adrian95/ssss810701~dgt.md)

- Role: Power Switch
- Manufacturer Part Number: SSSS810701
- Functional Group: Battery Power
- Manufacturer Name: Alps Alpine
- License: https://creativecommons\.org/licenses/by/4\.0/
- Role Details: SPDT used as physical load disconnect for direct 1S LiPo operation: center/common pin 2 from BATTERY, pin 1 to switched VSYS, pin 3 intentionally unused\. Power\-off removes MCU and alarm power so the latched alarm resets\.
- Part Type: s
- Datasheet URL: https://tech\.alpsalpine\.com/assets/products/catalog/ssss8\.en\.pdf

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]

*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://flux\.ai/roytyson/rocket\-finder\~x8](https://flux.ai/roytyson/rocket-finder~x8).*

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*Generated from [https://flux\.ai/roytyson/rocket\-finder\~x8](https://flux.ai/roytyson/rocket-finder~x8)*