portersky
df3d399610
Switch CRC from CCITT (0x07) to DVB-S2 (0xD5) to match ELRS. Adopt ELRS USB frame format: [addr][length][type][payload][crc]. Update frame type constants to match current ELRS protocol values. New skeleton modules (stub implementations with TODO comments): - crsf_telemetry.h/.c: telemetry decoders (GPS, battery, link..) - crsf_stream.h/.c: incremental streaming frame reader - crsf_param.h/.c: parameter protocol (read/write/set_power) Retained old frame format as *_legacy functions for backward compatibility with existing telemetry tool and tests. Add cel_serial_find_elrs_port() and cel_serial_open_probe() stubs to serial module for port auto-detection and baud probing.
59 lines
1.8 KiB
C
59 lines
1.8 KiB
C
#include "celrs/crsf_stream.h"
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#include <stdlib.h>
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#include <string.h>
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/* Valid CRSF address bytes (frame sync bytes) */
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static uint8_t const s_valid_addrs[] = {
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0x00, 0xC8, 0xC4, 0xEC, 0xEE, 0xEA, 0xEF
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};
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static int is_valid_addr(uint8_t addr) {
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for (size_t i = 0; i < sizeof(s_valid_addrs); i++) {
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if (s_valid_addrs[i] == addr) return 1;
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}
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return 0;
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}
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struct cel_crsf_stream {
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uint8_t buf[260]; /* internal buffer (max frame = 2 + 255 + 1 = 258) */
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size_t buf_len;
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};
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cel_crsf_stream* cel_crsf_stream_create(void) {
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/* TODO: allocate and zero-initialize the stream struct. */
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return NULL;
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}
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void cel_crsf_stream_destroy(cel_crsf_stream* stream) {
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/* TODO: free the stream struct. */
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(void)stream;
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}
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int cel_crsf_stream_feed(cel_crsf_stream* stream, uint8_t const* data,
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size_t len, cel_crsf_frame* out,
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size_t out_capacity) {
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/* TODO: append data to internal buffer, scan for complete frames.
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* Algorithm:
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* 1. Copy incoming bytes into internal buffer.
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* 2. While buffer has >= 4 bytes:
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* a. If buf[0] is not a valid address byte, pop(0) and continue.
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* b. Read length = buf[1].
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* c. Total frame = 2 + length.
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* d. If buffer < total, break (need more data).
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* e. Parse frame from buf[0..total-1].
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* f. On success (CRC valid), copy into out[] and advance buffer.
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* g. On failure (CRC invalid), discard frame and continue.
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* 3. Return number of valid frames parsed, or -1 on error. */
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(void)stream;
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(void)data;
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(void)len;
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(void)out;
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(void)out_capacity;
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return 0;
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}
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void cel_crsf_stream_reset(cel_crsf_stream* stream) {
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/* TODO: zero buf_len to discard any partial frame. */
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(void)stream;
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}
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