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Детальний опис (англійською мовою, можу розписати українською).

Design a compact OSD PCB that:

Interfaces with the Orange Cube via UART (MAVLink2) using a JST-GH connector.
Uses an STM32F030F4P6 to bridge UART to SPI for the AT7456E OSD chip.
Overlays flight data on an analog video signal (NTSC/PAL).
Connects to an FPV camera (video in) and VTX (video out).
Operates on 3.3V derived from the Cube’s 5V supply.

Components with LCSC Part Numbers

AT7456E OSD Chip
- LCSC Part: C82351
- Specs: SOP-28, 3.3V–5V, SPI interface, NTSC/PAL video overlay
- Price: ~$2.66
- Quantity: 1
STM32F030F4P6 Microcontroller
- LCSC Part: C111182
- Specs: TSSOP-20, 2.4V–3.6V, UART1, SPI1
- Price: ~$0.60
- Quantity: 1
27 MHz Crystal Oscillator
- LCSC Part: C16783
- Specs: 3.2 mm x 2.5 mm SMD, 27 MHz, 20 pF
- Price: ~$0.10
- Quantity: 1
Crystal Load Capacitors (22 pF)
- LCSC Part: C1304
- Specs: 0603 SMD, 22 pF, 50V, C0G/NP0
- Price: ~$0.01
- Quantity: 2
Power Regulator (AMS1117-3.3)
- LCSC Part: C84899
- Specs: SOT-223, 5V in, 3.3V out, 1A
- Price: ~$0.08
- Quantity: 1
Decoupling Capacitors (100 nF)
- LCSC Part: C1350
- Specs: 0603 SMD, 100 nF, 50V, X7R
- Price: ~$0.01
- Quantity: 3
Decoupling Capacitor (10 µF)
- LCSC Part: C15849
- Specs: 0805 SMD, 10 µF, 25V, X5R
- Price: ~$0.03
- Quantity: 1
Video Termination Resistors (75 ohms)
- LCSC Part: C25804
- Specs: 0603 SMD, 75 ohms, 1%, 1/10W
- Price: ~$0.01
- Quantity: 2
Video Coupling Capacitor (22 µF)
- LCSC Part: C15189
- Specs: 1206 SMD, 22 µF, 16V, X5R
- Price: ~$0.06
- Quantity: 1
Pull-Up Resistor (10 kΩ, Optional)
- LCSC Part: C25695
- Specs: 0603 SMD, 10 kΩ, 5%, 1/10W
- Price: ~$0.01
- Quantity: 1
UART Connector (4-pin JST-GH)
- LCSC Part: C2986198
- Specs: 1.25 mm pitch, SMD
- Price: ~$0.30
- Quantity: 1
Video Input Connector (3-pin JST-SH)
- LCSC Part: C168977
- Specs: 1.0 mm pitch, SMD
- Price: ~$0.15
- Quantity: 1
Video Output Connector (3-pin JST-SH)
- LCSC Part: C168977
- Specs: 1.0 mm pitch, SMD
- Price: ~$0.15
- Quantity: 1

AT7456E Pinout and Wiring Details

The AT7456E is a MAX7456 clone with an identical SOP-28 pinout. Below is the pinout and specific wiring for integration:

Pin 1 (VIN): Video input from FPV camera.
Pin 2–10: NC (not connected) or internal use; leave unconnected.
Pin 11 (OSC1): Crystal oscillator input.
Pin 12 (OSC2): Crystal oscillator output.
Pin 13 (GND): Ground.
Pin 14 (VDD): Power supply (3.3V from AMS1117).
Pin 15–22: NC or internal; leave unconnected.
Pin 23 (SCK): SPI clock from STM32.
Pin 24 (MOSI/SDIN): SPI data in from STM32.
Pin 25 (MISO/SDOUT): SPI data out (not used, leave unconnected).
Pin 26 (CS): SPI chip select from STM32.
Pin 27 (NC): Not connected.
Pin 28 (VOUT): Video output to VTX.

Wiring for AT7456E

Power:
- Pin 14 (VDD) to AMS1117-3.3 (C84899) output (3.3V).
- Pin 13 (GND) to ground plane.
- 100 nF (C1350) between Pin 14 and Pin 13, placed <5 mm from chip.
Crystal Oscillator:
- 27 MHz crystal (C16783) between Pin 11 (OSC1) and Pin 12 (OSC2).
- 22 pF (C1304) from Pin 11 to GND.
- 22 pF (C1304) from Pin 12 to GND.
- Traces <5 mm, symmetric, close to chip.
SPI Interface:
- Pin 23 (SCK) to STM32 PA5 (C111182, Pin 8, SPI1_SCK).
- Pin 24 (MOSI) to STM32 PA7 (C111182, Pin 10, SPI1_MOSI).
- Pin 26 (CS) to STM32 PA4 (C111182, Pin 7, SPI1_NSS).
- Pin 25 (MISO) unconnected (not required for OSD).
- Traces <5 mm, grouped, away from video lines.
Video Path:
- Pin 1 (VIN) to Video Input connector (C168977) Pin 1.
- 75-ohm (C25804) between Pin 1 and GND, near connector.
- Pin 28 (VOUT) to 22 µF (C15189) positive leg.
- 22 µF negative leg to Video Output connector (C168977) Pin 1.
- 75-ohm (C25804) between Pin 28 and GND, near connector.

Full Wiring Description

Power Distribution:
- UART connector (C2986198) Pin 1 (5V) to AMS1117-3.3 (C84899) input.
- AMS1117 GND to ground plane (UART Pin 4).
- AMS1117 output (3.3V) to:
  - AT7456E VDD (Pin 14).
  - STM32 VDD (C111182, Pin 1).
- 100 nF (C1350) and 10 µF (C15849) near AMS1117 (input and output).
- 100 nF (C1350) near AT7456E VDD.
- 100 nF (C1350) near STM32 VDD.
UART Interface (MAVLink2):
- UART connector Pin 2 (Cube TX) to STM32 PA10 (C111182, Pin 18, UART1_RX).
- UART Pin 4 (GND) to STM32 VSS (Pin 20).
- Optional 10 kΩ (C25695) from PA10 to 3.3V.
SPI Interface (STM32 to AT7456E):
- STM32 PA5 (Pin 8) to AT7456E SCK (Pin 23).
- STM32 PA7 (Pin 10) to AT7456E MOSI (Pin 24).
- STM32 PA4 (Pin 7) to AT7456E CS (Pin 26).
- AT7456E MISO (Pin 25) unconnected.
Video Path:
- Video Input (C168977) Pin 1 to AT7456E VIN (Pin 1).
- 75-ohm (C25804) at VIN to GND.
- AT7456E VOUT (Pin 28) to 22 µF (C15189) positive.
- 22 µF negative to Video Output (C168977) Pin 1.
- 75-ohm (C25804) at VOUT to GND.
Grounding:
- AT7456E GND (Pin 13), STM32 VSS (Pin 20), UART Pin 4, video connectors’ GND (Pin 2) to ground plane.
- Vias for multi-layer connectivity.

PCB Layout Considerations

Size: ~20 mm x 25 mm (2-layer).
Placement:
- AT7456E (C82351) center (SOP-28, ~18 mm wide).
- Crystal (C16783) + caps (C1304) below AT7456E.
- STM32 (C111182) left, near UART (C2986198).
- Video Input (C168977) top, Video Output (C168977) bottom.
- AMS1117 (C84899) + caps right.
Traces:
- UART: <10 mm, isolated from video.
- SPI: <5 mm, grouped, direct.
- Video: Wide (0.5 mm), >2 mm from digital signals.
Ground Plane: Bottom layer, stitched with vias.

Total Cost (Recap)

AT7456E: $2.66
STM32: $0.60
Crystal: $0.10
Load Capacitors: 2 × $0.01 = $0.02
AMS1117-3.3: $0.08
100 nF Capacitors: 3 × $0.01 = $0.03
10 µF Capacitor: $0.03
75-ohm Resistors: 2 × $0.01 = $0.02
22 µF Capacitor: $0.06
10 kΩ Resistor: $0.01
UART Connector: $0.30
Video Input Connector: $0.15
Video Output Connector: $0.15
Total: $4.21 (excluding shipping/taxes)

Notes

AT7456E Compatibility: Identical to MAX7456 in function and pinout, fully supported by ArduPilot OSD (set OSD_TYPE=1).
Firmware: STM32 needs MAVLink parsing and SPI control for AT7456E (same as MAX7456).
Verification: Check LCSC.com for current pricing/stock as of April 3, 2025.

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