STM32_RadioLink_SBUS_DMA
STM32F401CCU6 Blackpill
STM32 F4 FW 1.26.2
STM32CubeIDE v1.7.0
HAL
UART2 with DMA .
This code communicates with SBUS receiver. Only decoder.
The SBUS protocol uses an inverted serial logic with a baud rate of 100000, 8 data bits, even parity, and 2 stop bits. The SBUS packet is 25 bytes long consisting of:
* Byte[0]: SBUS header, 0x0F
* Byte[1 -22]: 16 channels, 11 bits each
* Byte[23]
* Bit 7: channel 17
* Bit 6: channel 18
* Bit 5: SBUS_SIGNAL_LOST (0x01)
* Bit 4: SBUS_SIGNAL_FAILSAFE (0x03)
* Byte[24]: SBUS footer (0x00)
Channels data is transferred to the CH variable.
Tested with R7FG v1.2 and RC6GS v1.
R7FG receiver will output a range of 170 - 1876 (neutral 1023) with channels set to a range of -100% to +100%. Using extended limits of -120% to +120% outputs a range of 0 to 2047, which is the maximum range acheivable with 11 bits of data.
