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Overview
CrsfParser is C++ library designed for decoding and encoding packets of CRSF FPV drone control protocol. The library used for CRSF packets translation and extracts only CRSF_FRAMETYPE_RC_CHANNELS_PACKED packets. For other packets types the library just detects them in data buffer. The library doesn’t have third-party dependencies, but test application depends on SerialPort library (provides methods to work with serial ports, source code included, Apache 2.0 license).
Documentation
Documentation: GO TO DOCUMENTATION
Simple interface
class CrsfParser
{
public:
/// Get library version.
static std::string getVersion();
/// Detect CRSF packet.
CrsfPacket detect(uint8_t nextByte, uint8_t* packet, int& size);
/// Get decoded RC channels.
void getRcChannels(uint32_t channels[16]);
/// Encode RC channels packet.
bool encodeRcChannels(uint32_t channels[16], uint8_t* packet, int& size);
};
Encode CRSF command example
// Fill channels.
uint32_t channels[16];
for (int i = 0; i < 16; ++i)
channels[i] = 992;
// Encoder RC channels.
uint8_t encodedPacket[64];
int encodedSize = 0;
parser.encodeRcChannels(channels, encodedPacket, encodedSize);
// Show data.
cout << "Encoded packet: ";
for (int i = 0; i < encodedSize; ++i)
cout << hex << (int)encodedPacket[i] << " ";
cout << dec << endl;
Decode CRSF message example
// CRSF packet with additional data
uint8_t rfChannelPacket[] = {
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xc8, 0x18, 0x16,
0xe0, 0x03, 0x1f, 0xf8, 0xc0, 0x07, 0x3e, 0xf0, 0x81, 0x0f, 0x7c,
0xe0, 0x03, 0x1f, 0xf8, 0xc0, 0x07, 0x3e, 0xf0, 0x81, 0x0f, 0x7c, 0xad,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
};
// Detect byte-by-byte.
CrsfParser parser;
uint8_t packet[64];
int packetSize = 0;
for (int i = 0; i < sizeof(rfChannelPacket); ++i)
{
CrsfPacket type = parser.detect(rfChannelPacket[i], packet, packetSize);
if (type == CrsfPacket::RC_CHANNELS)
{
uint32_t channels[16];
parser.getRcChannels(channels);
cout << "RC channels: ";
for (int i = 0; i < 16; ++i)
cout << channels[i] << " ";
cout << endl;
}
}
