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WM331 Camera Encoder board

mefistotelis edited this page Dec 23, 2022 · 3 revisions

Table of Contents

Function
Variants
Parts
Programming
External interfaces
Service interfaces
Board view
Schematics

Function

Contains Ambarella pipeline - the SoC, its external RAM and Flash memory and power regulators. This pipeline is responsible for receiving data from Camera Sensor and compressing it for SD-card storage. It also prepares another video stream, to be used for FPV.

Variants

The known variants are listed below.

Marking Overview
P01904.03 First version.

Parts

Marking Amt. Pkg. Function Specification
Ambarella H1-A1-RH ??312 NE??????J 1N? H1S75 1 BGA Ultra HD 4K Camera SoC
7XLID NQ283 YCD6 1 Micron NQ283 NAND
AFVJ 611 1
WE245 TI 56K A9GV 1 26-lead 6.3x4.3 PVQFN-N24 SN74AVC8T245 8-Bit Dual-Supply Bus Transceiver With Configurable Voltage Translation and 3-State Outputs description
?NA 1
trig FAD 1
8CB21 D9SRZ 2PYS / 8B847 B9SR2 2YKU 2 Micron MT52L256M32D1PF-107 WT:B; 8Gb lpDDR3-1866; RAM for Ambarella description
LZ 1

Programming

Chips Firmware Description
H1S75 m0100, m0101 Takes care of video encoding and controls firmware update process. Controls SD card slot. Consists of loader (01) and application (00).

External interfaces

The board contains one connector:

Marking Overview
TODO

Service interfaces

The following service pads exist on this board:

Marking Overview
TODO

Board view

Top of a P01904.03 board:

WM331 Camera Encoder board v3 A top

Bottom of the P01904.03 board:

WM331 Camera Encoder board v3 A bottom

Schematics

Functional diagram

flowchart LR
    Gimbal-FFC-cable((FFC to<br/>Gimbal))
    Gimbal-FFC-cable===Signal-Conditioner
    Gimbal-FFC-cable-- UART<br/>DUML ---Ambarella-SoC
    subgraph Camera Encoder board
    Signal-Conditioner[Video input<br/>transceiver/<br/>conditioner]
    Ambarella-SoC[Ambarella A9<br/>Camera SoC<br/>2x ARM and DSP]
    Ambarella-Xlat(quartz<br/>oscillator)---Ambarella-SoC
    Ambarella-SoC---Ambarella-RAM[lpDDR2<br/>SDRAM<br/>2GB]
    Ambarella-SoC---Ambarella-FLASH[NAND<br/>Flash]
    Encoder-CryptoAuth[ATSHA204<br/>Crypto<br/>Auth]
    Signal-Conditioner== image<br/>sensor<br/>data ===Ambarella-SoC
    Encoder-CryptoAuth---Ambarella-SoC
    end
    Interboard-SD-Pwr((inter-<br/>board conn<br/>to SD&Pwr))
    FFC-3in1((FFC to<br/>3-in-1))
    Ambarella-SoC-- UART<br/>DUML ---FFC-3in1
    Ambarella-SoC== low bit rate<br/>video stream ====FFC-3in1
    Ambarella-SoC== high bit rate<br/>video & photo ====Interboard-SD-Pwr
    Ambarella-SoC-- usb ----Interboard-SD-Pwr
Loading

Thick lines present propagation of video data. The video comes from sensor board through Flex Film Cable. To push such high data rate through the cable without degradation, signal conditioner in required. Then the sensor data goes to Ambarella, which is the central SoC for video data processing. It applies proper filtering to the data, then generates two streams out of it - high bandwidth stream is H.274 compressed and written to SD-card (if recording) on Gimbal Power and SD board, low bandwidth stream is sent to Receiver Main Processor 3-in-1 board.

Ambarella requires external RAM and NAND chips, and quartz oscillator for clock signal generation. The SoC also has access to CryptoAuth engine, which it can use to encrypt or decrypt a secret storage block, which contains encryption keys.

Hardware schematics

No schematics available.

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