add app WeatherStation

OFW PR 1833 by Skorpionm

lib/subghz/blocks/math.h

@@ -9,7 +9,11 @@
 #define bit_clear(value, bit) ((value) &= ~(1UL << (bit)))
 #define bit_write(value, bit, bitvalue) (bitvalue ? bit_set(value, bit) : bit_clear(value, bit))
 #define DURATION_DIFF(x, y) ((x < y) ? (y - x) : (x - y))
+#define abs(x) ((x) > 0 ? (x) : -(x))
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 /**
  * Flip the data bitwise.
  * @param key In data
@@ -25,3 +29,51 @@ uint64_t subghz_protocol_blocks_reverse_key(uint64_t key, uint8_t count_bit);
  * @return parity
  */
 uint8_t subghz_protocol_blocks_get_parity(uint64_t key, uint8_t count_bit);
+
+/**
+ * CRC-4.
+ * @param message array of bytes to check
+ * @param nBytes number of bytes in message
+ * @param polynomial CRC polynomial
+ * @param init starting crc value
+ * @return CRC value
+ */
+uint8_t subghz_protocol_blocks_crc4(
+    uint8_t const message[],
+    unsigned nBytes,
+    uint8_t polynomial,
+    uint8_t init);
+
+/**
+ * CRC-7.
+ * @param message array of bytes to check
+ * @param nBytes number of bytes in message
+ * @param polynomial CRC polynomial
+ * @param init starting crc value
+ * @return CRC value
+ */
+uint8_t subghz_protocol_blocks_crc7(
+    uint8_t const message[],
+    unsigned nBytes,
+    uint8_t polynomial,
+    uint8_t init);
+
+/**
+ * Generic Cyclic Redundancy Check CRC-8.
+ * Example polynomial: 0x31 = x8 + x5 + x4 + 1 (x8 is implicit)
+ * Example polynomial: 0x80 = x8 + x7 (a normal bit-by-bit parity XOR)
+ * @param message array of bytes to check
+ * @param nBytes number of bytes in message
+ * @param polynomial byte is from x^7 to x^0 (x^8 is implicitly one)
+ * @param init starting crc value
+ * @return CRC value
+ */
+uint8_t subghz_protocol_blocks_crc8(
+    uint8_t const message[],
+    unsigned nBytes,
+    uint8_t polynomial,
+    uint8_t init);
+
+#ifdef __cplusplus
+}
+#endif