The code and specifications for the KFly PCB version 3 and above

Stuff to fix

• Generalize RC Input, should not be dependent on the center value to determine if it is a "positive / negative only". Throttle will be used for more in the future.

Hardware Specifications

All PCBs follow the standard 36 x 36 mm outline with 30.5 x 30.5 mm mounting holes, unless nothing else is stated.

KFly PCB version 3:

• ST's STM32F405 CPU: 32-bit ARM Cortex-M4F @ 168 MHz with 32-bit FPU and DSP
• Invensense's MPU-6050 accelerometer / gyroscope
• Honeywell's HMC5983 magnetometer
• Meas. Spec.'s MS5611 pressure sensor
• 8 outputs (50 Hz / 400 Hz / Oneshot125 / Oneshot42 / Multishot / Dshot)
• 4 expansion connectors (3 UARTs & 1 CAN port)
• 6 slot RC input connector with support for (C)PPM up to 8 channels in and signal strength
• 433 MHz RF link for data, command and control transfers

KFly PCB version 4:

• ST's STM32F765 CPU: 32-bit ARM Cortex-M7F @ 216 MHz with 64-bit FPU, DSP and advanced branch prediction
• ST's LSM6DSM accelerometer / gyroscope
• ST's LPS22HB pressure sensor
• Separate analog and digital power supply with 6 V max input voltage
• 8 outputs (50 Hz / 400 Hz / Oneshot125 / Oneshot42 / Multishot / Dshot)
• 4 expansion connectors (4 UARTs & 1 CAN port)
• 6 slot RC input connector with support for (C)PPM and SBUS with up to 18 channels and signal strength indication
• MicroSD card holder for "Blackbox" flight logging

Software Specifications

Common features

• Runs ChibiOS 16.x
• USB Serial Bootloader - no need for an external programmer!
• Quaternion based Square-Root Multiplicative Extended Kalman Filter (SR-MEKF) provides estimation
• "Control signal to Motor"-mixing for different types of frames
• Flight control: Rate mode, Attitude mode and more to come

Cortex-M7 features

• The Cortex-M7 based (v. 4+) will be running Model Predictive Controllers (MPCs)