/* Usage example for the HEXBuilder class. This example shows how to convert a HEX string to a binary buffer and vice versa. */ #include void setup() { Serial.begin(115200); Serial.println("\n\n\nStart."); // Convert a HEX string like 6c6c6f20576f726c64 to a binary buffer { const char *out = "Hello World"; const char *hexin = "48656c6c6f20576f726c6400"; // As the string above is \0 terminated too unsigned char buff[256]; size_t len = HEXBuilder::hex2bytes(buff, sizeof(buff), hexin); if (len != 1 + strlen(out)) { Serial.println("Odd - length 1 is wrong"); } if (memcmp(buff, out, len) != 0) { Serial.println("Odd - decode 1 went wrong"); } // Safe to print this binary buffer -- as we've included a \0 in the hex sequence. Serial.printf("IN: <%s>\nOUT <%s\\0>\n", hexin, buff); }; { String helloHEX = "48656c6c6f20576f726c64"; const char hello[] = "Hello World"; unsigned char buff[256]; size_t len = HEXBuilder::hex2bytes(buff, sizeof(buff), helloHEX); if (len != strlen(hello)) { Serial.println("Odd - length 2 is wrong"); } if (strcmp((char *)buff, hello) != 0) { Serial.println("Odd - decode 2 went wrong"); } } { const unsigned char helloBytes[] = {0x48, 0x56, 0x6c, 0x6c, 0x6f, 0x20, 0x57, 0x6f, 0x72, 0x6c, 0x64}; String helloHEX = "48566c6c6f20576f726c64"; String out = HEXBuilder::bytes2hex(helloBytes, sizeof(helloBytes)); if (out.length() != 2 * sizeof(helloBytes)) { Serial.println("Odd - length 3 is wrong"); } // we need to ignore case - as a hex string can be spelled in uppercase and lowercase if (!out.equalsIgnoreCase(helloHEX)) { Serial.println("Odd - decode 3 went wrong"); } } { const unsigned char helloBytes[] = {0x6c, 0x6c, 0x6f, 0x20, 0x57, 0x6f, 0x72, 0x6c, 0x64}; const char helloHex[] = "6c6c6f20576f726c64"; char buff[256]; size_t len = HEXBuilder::bytes2hex(buff, sizeof(buff), helloBytes, sizeof(helloBytes)); if (len != 1 + 2 * sizeof(helloBytes)) { Serial.println("Odd - length 4 is wrong"); } // we need to ignore case - as a hex string can be spelled in uppercase and lowercase if (strcasecmp(buff, helloHex)) { Serial.println("Odd - decode 4 went wrong"); } } Serial.println("Done."); } void loop() {}