WM220 Core Board A
Function
Variants
Parts
Programming
External interfaces
Service interfaces
Board view
Schematics
The board stores most of computational power of the Dji Mavic drone. It contains video encoder for both FPV and SD-card, but also video recognition for positioning (VPS) and gesture control. It also contains transceiver and high-frequency components which make up Ocusync radio channel.
Several versions of the module are known.
| Marking | Overview |
|---|---|
| P01549.07 | The first version; lacks Leadcore pipeline, but integrates Atheros instead. Maybe pre-release Mavic was Wifi-only? |
| P01817.08 | Most popular production board. |
| Marking | Amt. | Pkg. | Function | Specification |
|---|---|---|---|---|
| ACP ACPD4GD31D3 ED87458KB | 1 | 169-ball FBGA | ACP IRIS411 LTE Cat 4 Transceiver, with I/Q samples and control messages exchanged on a DigRF v4 serial interface; acts as RF front-end for LC1860C | description |
| Skyworks 77814-1 87144.1 1605 MX | 1 | 24-pad MCM | SKY77814-11 Power Amplifier Module for LTE and AXGP bands | description |
| W1A 3A | 6 | 3-pin SOT-23 | PMBT3904 NPN switching transistor | description |
| S 20 | 3 | 6-lead 1.5x1.5 QFN-33 | SKY13320-374LF: 0.1-6.0 GHz GaAs SPDT Switch | description |
| Elpida B8132B4PM-1D-F 16160R08500 | 1 | 168-ball 12×12 FBGA | Embedded LPDDR2 SDRAM for Ambarella | description |
| Ambarella A9-A1-RH S1610 NA23X-KD ABM7N1 A9S75 | 1 | BGA | Ultra HD 4K Camera SoC | brief |
| MXIC X161109 MX30LF2G18AC-XX1 68981505A1 | 1 | 63-ball 11x9 VFBGA | 3V SLC 2GBit NAND Flash memory; stores programming for A9S75 | description |
| 4YE12 NQ283 | 1 | 63-ball 11x9 VFBGA | Micron MT29F2G08ABAEAH4 NAND Flash; stores programming for A9S75; is MX30LF2G replacement on some boards | description |
| Movidius MA2100A 546-A2 300T | 1 | |||
| 78B | 2 | |||
| AR4 | 2 | |||
| BR4 | 2 | Philips BSR33 Si PNP transistor; Uce 80V, Ic 1A | ||
| 3PEAK TP2274 QKFp | 1 | TP2274 - 36V, 7MHz Bandwidth, RRO Quad Op‐amps | description | |
| M058ZDN S13AD 2508802S-ZZ ARM / M058ZDN 622AD 26196075-ZZ ARM | 1 | Nuvoton M051 Series MCU with ARM Cortex-M0 core | description | |
| T120 PuHS | 2 | Quartz oscillator, 12MHz | ||
| GL850H 0MA0111 5179161 | 1 | 64-Pin LQFP | Genesys Logic GL850, USB 2.0 4-port HUB Controller | description |
| J1 F | 5 | |||
| C3FGC | 2 | 4-lead 7x1.5 SMD | plastic covered metal case with quartz oscillator; Seiko Epson MC-146 series or its knock-off, exact model unknown | description |
| LLTB | 1 | |||
| KL2 B1 | 1 | |||
| LFW 63 | 1 | |||
| LN7B | 1 | |||
| LLUB | 1 | |||
| AEUG | 2 | |||
| Leadcore LC1860C T2F21316 123 THA918.00 ARM | 1 | Quad-core 1.5GHz ARM Cortex-A7 SoC with Mali-T628 GPU and LTE Cat 4 baseband modem | ||
| Leadcore LC1160 S2T2 5215 A00 H98308 | 1 | Power Management Unit and Audio codec, which meets LC1860 requirements | ||
| SEC 625 B213 KMFJ20005A S4CK6A9SC | 1 | BGA221 | Samsung KMFJ20005A-B213 Embedded Multi-Chip Package: 4GB eMMC + 4GB lpDDR3 | |
| LCMXO2 1200HC 4MG1320 A6011RO2 0L24C33934011 | 1 | Lattice MachXO2, Flexible Interface Bridging FPGA | description datasheet | |
| N20 027 SC057B | 1 | Quartz oscillator | ||
| NS 66A1XHU 26480CF | 1 | LM26480 Externally Programmable Dual High-Current Step-Down DC/DC and Dual Linear Regulators | datasheet | |
| 34-pin FPC CON | 1 | 34-pin 9.4x2.2 | LANRUISI 2x17pin female connector, 0.4 mm pitch; Flexible Printed Circuit Connectors, for gimbal with camera | |
| 30-pin FPC CON | 1 | 30-pin 8.6x2.2 | LANRUISI 2x15pin female connector, 0.4 mm pitch; Flexible Printed Circuit Connectors | |
| 24-pin FPC CON | 1 | 24-pin 7.4x2.2 | LANRUISI 2x12pin female connector, 0.4 mm pitch; Flexible Printed Circuit Connectors, for gimbal with camera |
| Chips | Firmware | Description |
|---|---|---|
| A9S75, EDB8132B, MX30LF2G/MT29F2G | m0100, m0101 | Takes care of video encoding. Controls SD card slot. Consists of loader (01) and application (00). |
| LC1860C | m0801, but see m0901 | Radio communication and control of intelligent flight functions. The module identifier is m0801, but in later platforms was renamed to m0901. |
| MA2100A | m0802 | Collision avoidance and sensory support for intelligent flight functions. |
| Marking | Overview |
|---|---|
| TODO |
The following service pads exist on this board:
| Marking | Overview |
|---|---|
| TODO |
Top of a P01549.07 board:
Bottom of the P01549.07 board:
Top of a P01817.08 board:
Bottom of the P01817.08 board:
Top of another P01817.08 board:
Bottom of the P01817.08 board:
flowchart LR
Wifi-FFC-cable((FFC to<br/>Wifi))
Gimbal-FFC-cable((FFC to<br/>Gimbal))
Gimbal-FFC-cable===Signal-Conditioner
Gimbal-FFC-cable-- UART<br/>DUML ---Ambarella-SoC
Processing-SoC------Wifi-FFC-cable
subgraph Core Board A
Processing-SoC[LC1860C SoC<br/>Quad-core<br/>ARM Cortex-A7]
Encoder-CryptoAuth[ATSHA204<br/>Crypto<br/>Auth]
subgraph Camera Encoder block
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-FLASH[NAND<br/>Flash]---Ambarella-SoC
Signal-Conditioner== image<br/>sensor<br/>data ===Ambarella-SoC
Ambarella-SoC== high bit rate<br/>video & photo ===Ambarella-SD-Slot(SD-card slot)
end
Ambarella-SoC---Encoder-CryptoAuth
Encoder-CryptoAuth---Processing-SoC
Ambarella-SoC-- UART<br/>DUML ---Processing-SoC
Ambarella-SoC== low bit rate<br/>video stream ====Processing-SoC
Processing-SoC===LTE-Transceiver
Ambarella-SD-Card[SD-card]
Ambarella-SD-Slot---Ambarella-SD-Card
subgraph Occusync transceiver block
LTE-Transceiver[IRIS411<br/>LTE Cat 4<br/>transceiver]
LTE-Transceiver===RF-Tx-Amp-A[RF power<br/>out amp]
LTE-Transceiver---RF-Rx-Amp-A[RF LNA<br/>inp amp]
LTE-Transceiver===RF-Tx-Amp-B[RF power<br/>out amp]
LTE-Transceiver---RF-Rx-Amp-B[RF LNA<br/>inp amp]
RF-Switch-A[RF<br/>switch]
RF-Switch-B[RF<br/>switch]
RF-Tx-Amp-A===RF-Switch-A
RF-Rx-Amp-A---RF-Switch-A
RF-Tx-Amp-B===RF-Switch-B
RF-Rx-Amp-B---RF-Switch-B
end
end
Antenna-A1((Ant))
Antenna-A2((Ant))
Antenna-B1((Ant))
Antenna-B2((Ant))
RF-Switch-A---Antenna-A1
RF-Switch-A---Antenna-A2
RF-Switch-B---Antenna-B1
RF-Switch-B---Antenna-B2
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 main camera 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), low bandwidth stream is sent to LC1860C for applying intelligent functions and radio transmission to the RC.
The antennas can also receive DUML packets from the RC, in which case the input RF signal is amplified through LNA and received through LTE Transceiver. The DUML packets are provided to the LC1860C SoC, and from there routed to other modules of the drone.
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. All the same goes for LC1860C, but that will be shown in detail on the diagram focused on intelligent functions.
flowchart LR
FFC-Sensors-Down((FFC<br/>to Down<br/>Cameras))
FFC-Sensors-Forward((FFC to<br/>Forward<br/>Cameras))
FFC-Sensors-Down---Movidius-SoC
FFC-Sensors-Forward---Movidius-SoC
subgraph Core Board A
Processing-SoC[LC1860C SoC<br/>Quad-core<br/>ARM Cortex-A7]
Inteligent-FPGA[LCMXO2 FPGA<br/>1280 LUT]
Inteligent-FPGA---Inteligent-Xlat(quartz<br/>oscillator)
Processing-SoC----Inteligent-FPGA
Movidius-SoC[MA2100A SoC<br/>Myriad VPU]
Movidius-SoC---Movidius-Xlat(quartz<br/>oscillator)
Processing-PMU[LC1160 PMU<br/>for Leadcore]
Movidius-SoC----Processing-SoC
Processing-PMU---Processing-SoC
Processing-SoC---Processing-RAM-EMMC[4GB eMMC<br/>4GB lpDDR3]
Processing-Xlat(quartz<br/>oscillator)---Processing-SoC
subgraph Camera Encoder block
Ambarella-SoC[Ambarella A9<br/>Camera SoC<br/>2x ARM and DSP]
end
Encoder-CryptoAuth[ATSHA204<br/>Crypto<br/>Auth]
Ambarella-SoC---Encoder-CryptoAuth
Ambarella-SoC== low bit rate<br/>video stream ====Processing-SoC
Encoder-CryptoAuth---Processing-SoC
Processing-SoC----TOF-Driver
subgraph Ultrasonic Sonar block
TOF-Driver[M058ZDN uC<br/>ToF driver<br/>ARM Cortex-M0]
TOF-Driver-Xlat(quartz<br/>oscillator)
TOF-Comparator[Comparator]
TOF-Spk((SPK))
TOF-Mic((MIC))
TOF-Out-Switch(Output<br/>switches)
TOF-Inp-Amp[Input<br/>amps]
TOF-Out-Switch---TOF-Spk
TOF-Comparator---TOF-Inp-Amp
TOF-Comparator---TOF-Out-Switch
TOF-Inp-Amp---TOF-Mic
TOF-Driver---TOF-Comparator
TOF-Driver---TOF-Out-Switch
TOF-Driver-Xlat---TOF-Driver
end
end
FFC-Flight-Control((FFC<br/>to Flight<br/>Control))
Processing-SoC--------FFC-Flight-Control
No schematics available.