thebears
bbdcc1e623
- main.c: file-header comment describing the hardware and operation, logic split into named phases (sleep_until_interrupt, wake_peripheral_rails, take_counts_snapshot, send_wheel_counts_report, handle_minute_alarm, init_all_hardware); shared state renamed to say what it is and made static. - rfm69.c: reorganized into six labeled sections; cond_1/2/3 and hash scratch globals replaced by a reply_acknowledges() helper with clear locals; packet layout and every init register write documented. - LOG() macro (compiled out when DO_UART is off) replaces the #if DO_UART blocks that obscured the logic. - Drivers: file-header comments; named RTC_REG_*/RTC_ALM_MASK_BIT constants; EEPROM spool scheme documented; ADC_CHANNEL_BANDGAP named; repeated pin if/else helpers collapsed to SET_PIN_TO(). - Removed unused globals/buffers and commented-out code; ran clang-format with the project style. Register writes and radio protocol are byte-identical. Builds clean under -Wall -Wextra on gnu17 and c23; flash 13028 -> 12830 B, static RAM 1038 -> 999 B. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01YVJKatfeMJjAmuH9KYiLuv
109 lines
3.4 KiB
C
109 lines
3.4 KiB
C
// Minimal NDEF parser: finds the first record in a raw tag dump and accepts
|
|
// only a short text record, whose text becomes the node's "name,diameter"
|
|
// identity string.
|
|
|
|
#include "ndef.h"
|
|
// Everything read here comes off an NFC tag that anyone can write, so every
|
|
// length taken from the buffer is bounds-checked before it is used.
|
|
#define NDEF_NEED(n) \
|
|
{ \
|
|
if ((addr + (uint16_t)(n)) > buf_len) { \
|
|
NDEF_MSG.success = NDEF_ERR_TRUNCATED; \
|
|
return NDEF_MSG; \
|
|
} \
|
|
}
|
|
|
|
ndef_message readNDEFText(unsigned char* buf, uint8_t buf_len)
|
|
{
|
|
uint16_t addr = 0;
|
|
NDEF_MSG.success = 0;
|
|
NDEF_MSG.payload_len = 0;
|
|
NDEF_MSG.payload[0] = '\0';
|
|
|
|
NDEF_NEED(2);
|
|
if (buf[0] != NDEF_TLV) {
|
|
NDEF_MSG.success = 1;
|
|
return NDEF_MSG;
|
|
}
|
|
|
|
if (buf[1] == 0xFF) {
|
|
NDEF_MSG.success = 2;
|
|
return NDEF_MSG;
|
|
};
|
|
|
|
// int len_field = buf[1];
|
|
addr = 2;
|
|
|
|
NDEF_NEED(3);
|
|
// bool is_short_record = (buf[addr] & NDEF_SHORT_RECORD) == NDEF_SHORT_RECORD;
|
|
bool has_id_length = (buf[addr] & NDEF_ID_LEN) == NDEF_ID_LEN;
|
|
uint8_t tnf = buf[addr] & 0x7;
|
|
addr += 1; // 3
|
|
|
|
uint8_t type_length = buf[addr];
|
|
addr += 1; // 4
|
|
|
|
uint8_t payload_length = buf[addr];
|
|
addr += 1; // 5
|
|
|
|
uint8_t id_length = 0;
|
|
if (has_id_length) {
|
|
NDEF_NEED(1);
|
|
id_length = buf[addr];
|
|
addr += 1;
|
|
}
|
|
|
|
// Only the first type byte is ever inspected, so skip the rest rather than
|
|
// copying them into a tag-sized VLA.
|
|
NDEF_NEED(type_length);
|
|
uint8_t type_value_0 = (type_length > 0) ? buf[addr] : 0;
|
|
addr += type_length;
|
|
|
|
if (type_value_0 != NDEF_TEXT_RECORD) {
|
|
NDEF_MSG.success = 11;
|
|
return NDEF_MSG;
|
|
};
|
|
if (tnf != TNF_KNOWN) {
|
|
NDEF_MSG.success = 12;
|
|
return NDEF_MSG;
|
|
};
|
|
|
|
if (has_id_length && (id_length > 0)) {
|
|
NDEF_NEED(id_length);
|
|
addr += id_length;
|
|
}
|
|
|
|
NDEF_NEED(1);
|
|
uint8_t lang_str_len = buf[addr];
|
|
|
|
// payload_length covers the language-length byte plus the language code
|
|
// plus the text. Subtracting without this check wraps a uint8_t to ~250.
|
|
if (payload_length < ((uint16_t)lang_str_len + 1)) {
|
|
NDEF_MSG.success = NDEF_ERR_BAD_LENGTH;
|
|
return NDEF_MSG;
|
|
}
|
|
payload_length -= lang_str_len; // Language string
|
|
payload_length -= 1; // The byte that says how long the language string is
|
|
|
|
NDEF_NEED((uint16_t)lang_str_len + 1);
|
|
addr += lang_str_len;
|
|
addr += 1;
|
|
|
|
// Leave room for the terminator the UART print and strchr() both rely on.
|
|
if (payload_length > (sizeof(NDEF_MSG.payload) - 1)) {
|
|
payload_length = sizeof(NDEF_MSG.payload) - 1;
|
|
}
|
|
NDEF_NEED(payload_length);
|
|
|
|
for (uint8_t i = 0; i < (payload_length); i++) {
|
|
NDEF_MSG.payload[i] = buf[addr];
|
|
addr += 1;
|
|
}
|
|
NDEF_MSG.payload[payload_length] = '\0';
|
|
NDEF_MSG.payload_len = payload_length;
|
|
|
|
LOG(NDEF_MSG.payload);
|
|
LOG("\n");
|
|
|
|
return NDEF_MSG;
|
|
}; |