Proximity Camera Board Design

flux

I’ll add a single-cell LiPo power path: USB-C charges the battery, the board can run from battery when USB is absent, and the existing 3.3 V rail will be updated so it can accept the battery source safely. I’ll size it against the existing ESP32/camera peak load, then wire and re-run ERC.

flux

I started the LiPo battery upgrade and inspected the existing power path: USB-C VBUS currently feeds a PAM2305 fixed 3.3 V buck regulator, which powers the ESP32-S3, camera, and VCNL4040 on 3V3.
Important finding: a single-cell LiPo ranges about 4.2 V down to ~3.0 V, so the current buck-only 3.3 V regulator is not ideal for full battery operation. The right architecture is:
  • USB-C 5 V → single-cell LiPo charger / power-path IC
  • LiPo battery connector → charger BAT pin
  • charger SYS/output → 3.3 V buck-boost regulator
  • buck-boost output → existing 3V3 rail
I was blocked by project credits before I could add parts or wire the schematic. Remaining work:
  1. Select charger/power-path IC, likely BQ24074/MCP73871-class.
  2. Select 3.3 V buck-boost regulator rated for ESP32-S3 + camera peak current.
  3. Add JST LiPo connector, charger passives, battery thermistor/program resistor as required.
  4. Replace or bypass the existing PAM2305 buck with the buck-boost stage.
  5. Update power-budget notes and rerun ERC to zero unresolved violations.
Use BQ24074
Compare charger ICs
Find battery connector
Calculate peak current
Document power architecture

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Project Specification
Design Summary
Status: Draft / Review / Approved
Manufacturing target: Prototype / EVT / DVT / PVT / Production
Software / firmware: repository link
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System context
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Electrical
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Dependencies
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  • Design Summary

  • Scope

  • System context

  • Requirements

  • Functional

  • Electrical

  • Mechanical / environmental

  • Key constraints

  • Dependencies and risks

  • Validation

  • Release-facing notes

  • Change notes / open questions

ESP32-S3 Proximity Camera

ESP32-S3 Proximity Camera thumbnail
WiFi-enabled ESP32-S3 camera board with proximity-triggered wake/hold detection. Captures and uploads an image to a server when a person/object remains nearby for 3 seconds.

Properties

Properties describe core aspects of the project.

Pricing & Availability

Distributor

Qty 1

Arrow

$0.88–$1.76

Digi-Key

$5.04–$6.17

HQonline

$1.39–$1.54

LCSC

$7.77–$7.99

Mouser

$9.68

TME

$1.19

Verical

$1.44–$2.40

Controls