P3X OFDM Receiver board
Function
Variants
Parts
Programming
External interfaces
Service interfaces
Board view
Schematics
The OFDM Receiver module is responsible for pairing with RC and communicating with it. The name comes from Orthogonal Frequency Division Multiplexing - which is a way of transferring broadband data. It implements the Lightbridge technology, and is also a middleman between the gimbal and flight controller.
There are multiple versions of the board, with two major lines. The older OFDM boards implement Lightbridge via Altera FPGA chip, while later boards use Artosyn SDR chips. Switching from multi-purpose chips to dedicated transceivers reduced cost and power consumption of the boards.
| Marking | Overview |
|---|---|
| P01007.06 | First known version. |
| P01007.08 | Switched to different voltage regulators. |
| P01007.14 | Switched from FPGA to SDR; often called OFDM v2 module. |
Full list of known components is presented in the table.
| Marking | Amt. | Pkg. | Function | Specification |
|---|---|---|---|---|
| STM32F 103CBU6 GH24W 93 CHN 516 | 1 | 48-lead 7x7 UFQFPN | Mainstream Performance line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN; Lightbridge MCU | description |
| ATH520 64DM Y | 1 | 8-pin | SPI Serial EPPROM integrated chip; FPGA bitstream storage | |
| 25Q064A 13E40 60 CHN 51712S | 1 | 8-pin 4x5 SOP | Micron Serial NOR Flash Memory; 64Mb, 1.8V, Multiple I/O, 4KB Sector Erase | datasheet |
| AEKF | 1 | 8-pin SOT23 | Maxim MAX3051EKA-T CAN Transceiver | |
| PA 5QA | 1 | 3x3 UDFN/WSON | Mini Linear Regultor; part used is DI AP7361ADJ, but it could also be TI TPS7A16 | DI datasheet TI description |
| 1755 ADJ #518 0220 | 1 | 16-lead 4x4 LFCSP-WQ | 1.2A Low-Vin, Adjustable-Vout LDO Linear Regulator | description |
| AD9363 BBCZ #1518 3144402.1 Singapore | 1 | 144-ball 10x10 CSP-BGA | Analog Devices Agile Radio frequency (RF) 2x2 transceiver with integrated 12-bit DACs and ADCs; Lightbridge RF part | description |
| VUBI TI 54 SI8F | 3 | 16-pin 3x3 QFN-4444 | Texas Instruments TLV62130RGTR 3V to 17V 3A Step-Down Converter | description |
| 22003 KA1614 CL012 | 2 | Avago MGA-22003 2.3-2.7 GHz 3x3mm WiMAX and WiFi Power Amplifier | description | |
| 9037 6620 | 2 | TriQuint TQP3M9037 Ultra Low Noise, High Linearity LNA | datasheet | |
| S 20 | 4 | 6-lead 1.5x1.5 QFN | SKY13320-374LF: 0.1-6.0 GHz GaAs SPDT Switch | description |
| 302AMIL 59400M 1519 | 1 | |||
| AC | 1 | diode? | ||
| TK2S 519 | 1 | Quartz oscillator? | ||
| T120 MeLS | 1 | Quartz oscillator, 12 MHz | ||
| 24.000 53 Rite | 1 | Quartz oscillator, 24 MHz | ||
| Altera Cyclone V 5CEFA4U19I7 | 1 | 484-ball UFBGA | FPGA; Cyclone V E model 5CEA4, temp. range -40 to 100 deg C; Lightbridge digital part | description |
| CY7C68013A-56 LTXC 1531 B 04 CYP squareC | 1 | 56-lead 8x8 QFN | EZ-USB FX2LP USB Microcontroller High-Speed USB Peripheral Controller; receives video from camera | description |
The part list is almost identical to P01007.08. The changes are TLV62130RGTR regulators which have been replaced. Only new components will be provided in the table.
| Marking | Amt. | Pkg. | Function | Specification |
|---|---|---|---|---|
| IAEU6 | 2 | Step-Down Converter |
Full list of known components is presented in the table.
| Marking | Amt. | Pkg. | Function | Specification |
|---|---|---|---|---|
| STM32F 103CBU6 GH24W 93 CHN 536 | 1 | Mainstream Performance line, ARM Cortex-M3 MCU with 128 Kbytes Flash, 72 MHz CPU, motor control, USB and CAN; Lightbridge MCU | description | |
| ATH542 64DM Y A3GXAA | 1 | 8-pin | SPI Serial EPPROM integrated chip; FPGA bitstream storage | |
| AEKF | 1 | Maxim MAX3051EKA-T CAN Transceiver | ||
| K7K CN | 1 | |||
| PA 6DA | 1 | Step-Down Converter? | ||
| Xlat 20.000 605E | 1 | quartz oscillator, 20 MHz | ||
| M9Y9975 46.5.8 | 1 | quartz oscillator? | ||
| S 20 | 4 | SKY13320-374LF: 0.1-6.0 GHz GaAs SPDT Switch | description | |
| Xlat 24.000 68 | 1 | quartz oscillator, 24 MHz | ||
| Xlat T120 Px25 | 1 | quartz oscillator, 12 MHz | ||
| IAEU6 | 2 | Step-Down Converter | ||
| 53 625 | 1 | |||
| VS6 U | 1 | |||
| CY7C68013A-56 LTXC 1531 B 04 TWN CYP 626064 squareC | 1 | EZ-USB FX2LP USB Microcontroller High-Speed USB Peripheral Controller; receives video from camera | description | |
| PA 5206 WNSA | 2 | |||
| Artosyn AR8003 CAK841 1603 | 1 | RF transciever | ||
| Artosyn AR8001 612P6042 | 1 | Video encoder |
| Chips | Firmware | Description |
|---|---|---|
| cy7c68013a | m1500 | Provides communication with camera module, including video transmission. |
| Altera Cyclone 5 E + ATH542 | m1900 | Lightbridge FPGA air part; NAND flash memory stores the programming and the FPGA chip reads it during each startup. |
| STM32F103 | m0900 | Lightbridge MCU; configures and drives FPGA and transciever. |
Connectors on the board are:
| Marking | Overview |
|---|---|
| CAMERA 6-pin 1.25mm ribbon cable con. | ribbon cable to the Gimbal top board |
| CENTER 6-pin ribbon cable con. | ribbon cable to the ESC center board |
The following service pads exist on this board:
| Marking | Overview |
|---|---|
| 6V | CENTER con. power |
| GND | CENTER con. ground |
| DP | CAMERA con. USB-DP |
| DM | CAMERA con. USB-DM |
| FAN_VCC | Cooling fan con. |
| FAN_GND | Cooling fan con. |
| SWCLK | |
| SWDIO | |
| GND | Ground |
| 5V | Power |
| TX | CENTER con. FC serial transmit |
| RX | CENTER con. FC serial receive |
| GND | Ground |
| MOSI | SPI Master Output Slave Input line |
| MISO | SPI Master Input Slave Output line |
| 3V? | Power; marking behind connector |
| CANL2 | |
| CANH2 | |
| GND | Ground |
| SCK | SPI Clock line |
| NSS | SPI Slave Select line |
| 3V3_MCU | Power |
| 5V | Power |
| VDDA33_VCO1 | |
| IFCLK | |
| SLRD# | |
| SLWR# | |
| FLAGC# | |
| FLAGB# | |
| RX1 | |
| TX1 | |
| RX2 | |
| TX2 | |
| GND | Ground |
| 1V2 | Power |
| 1V8 | Power |
| VCCMCU_3V3 | |
| CLK | |
| ENB | |
| DO | |
| DI |
Top of a P01007.06 board:
Bottom of the P01007.06 board:
Top of a second P01007.06 board (poor image but visible behind shielding):
Bottom of the second P01007.06 board:
Top of a third P01007.06 board (more markings visible):
Bottom of the third P01007.06 board:
Top of a fourth P01007.06 board (FPGA marking visible):
Bottom of the fourth P01007.06 board:
Top of a P01007.08 board:
Bottom of the P01007.08 board:
Top of a P01007.14 board:
Bottom of the P01007.14 board:
The following schematics were made by enthusiasts: