String inp = "01101000"; int decimalValue = 0; void setup() { Serial.begin(115200); while (!Serial) { ; // wait for serial port to connect. Needed for native USB } Serial.println(""); Serial.println(inp); String binary = inp.substring(2); Serial.println(binary); for (int i = 0; i < binary.length(); i++) { // Calculate the value of the current bit int bitValue = binary.charAt(i) - '0'; // Update the decimal value by shifting the bit to its correct position decimalValue = (decimalValue << 1) | bitValue; } Serial.println(decimalValue); Serial.println(""); } void loop() { // put your main code here, to run repeatedly: delay(1000); }