iFlight Borg 5S RX Flight Controller

The iFlight Borg 5S RX is a 20x20mm flight controller with an ELRS 2.4GHz receiver built in. It runs an AT32F435 processor with an ICM42688P gyro and takes 4-8S directly (LiHV included), so one compact board covers both the flight controller and the radio link. The "5S" in the name is iFlight's shorthand for 5-inch builds, not a voltage limit.

Key features

• Onboard ELRS 2.4GHz receiver with an integrated antenna, wired to UART4 — no separate receiver board needed, though an external receiver is still supported.
• 4-8S input with LiHV support, so the same board suits 4S micros and 6S or 8S builds.
• Dual BEC (5V 2.5A and 12V 2A) powers a VTX directly, with remote on/off switching from the transmitter.
• Supports DJI, SmartAudio, IRC Tramp and HDZero VTX protocols out of the box.
• 20x20mm mounting for compact frames and stacks.

Specifications

• MCU: AT32F435RGT7
• Gyro: ICM42688P
• Barometer: none
• OSD: AT7456E
• Blackbox: 16MB flash
• UARTs: 4
• Motor outputs: 4
• Input voltage: 4-8S LiPo/LiHV
• Onboard receiver: ELRS 2.4GHz
• BEC output: 5V/2.5A, 12V/2A
• Mounting: 20x20mm (4mm holes)
• Board size: 34 x 27mm
• Weight: 7g
• Firmware: Betaflight (target IFLIGHT_BLITZ_ATF435)

UART1 is wired for a VTX, UART2 for ESC telemetry, and UART5 is free for GPS or another sensor.