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60 lines
2.0 KiB
C
60 lines
2.0 KiB
C
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#ifndef AHRS_SPI_PROGRAM_H
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#define AHRS_SPI_PROGRAM_H
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/* Special packets to enter programming mode.
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Note: these must both be SPI_PROGRAM_REQUEST_LENGTH long.
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Pad with spaces if needed.
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*/
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#define SPI_PROGRAM_REQUEST "AHRS START PROGRAMMING "
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#define SPI_PROGRAM_ACK "AHRS PROGRAMMING STARTED"
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#define SPI_PROGRAM_REQUEST_LENGTH 24
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/**Proposed programming protocol:
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In the master:
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1) Send a AhrsProgramPacket containing the relevant data.
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Note crc is a CRC32 as the CRC8 used in hardware can be fooled.
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2) Keep sending PROGRAM_NULL packets and wait for an ack.
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Time out if we waited too long.
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3) Compare ack packet with transmitted packet. The data
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should be the bitwise inverse of the data transmitted.
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packetId should correspond to the transmitted packet.
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4) repeat for next packet until finished
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5) Repeat using verify packets
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Returned data should be exactly as read from memory
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In the slave:
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1) Wait for an AhrsProgramPacket
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2) Check CRC then write to memory
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3) Bitwise invert data and add it to the return packet
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4) Copy packetId from received packet
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5) Transmit packet.
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6) repeat until we receive a read packet
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7) read memory as requested until we receive a reboot packet
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Reboot packets had better have some sort of magic number in the data,
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just to be absolutely sure
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*/
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typedef enum { PROGRAM_NULL, PROGRAM_WRITE, PROGRAM_READ, PROGRAM_ACK, PROGRAM_REBOOT, PROGRAM_ERR} ProgramType;
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#define SPI_MAX_PROGRAM_DATA_SIZE (14 * 4) //USB comms uses 14x 32 bit words
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#define REBOOT_CONFIRMATION "AHRS REBOOT"
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#define REBOOT_CONFIRMATION_LENGTH 11
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/** Proposed program packet defintion
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*/
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typedef struct {
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ProgramType type;
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uint32_t packetId; //Transmission packet ID
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uint32_t address; //base address to place data
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uint32_t size; //Size of data (0 to SPI_MAX_PROGRAM_DATA_SIZE)
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uint8_t data[SPI_MAX_PROGRAM_DATA_SIZE];
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uint32_t crc; //CRC32 - hardware CRC8 can be fooled
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uint8_t dummy; //for some reason comms trashes the last byte sent
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} AhrsProgramPacket;
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uint32_t GenerateCRC (AhrsProgramPacket * packet);
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#endif
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