Convert two 16 Bit Registers to 32 Bit real value flutter - flutter

Question

I am using a Modbus flutter lib, reading 2 registers I obtain:
[22136, 4660]
This means: 0x12345678 I need a function to convert it to a 32 bit real value: 305419896, in easymodbustcp library I found:
/**
* Convert two 16 Bit Registers to 32 Bit real value
* #param registers 16 Bit Registers
* #return 32 bit real value
*/
public static float ConvertRegistersToFloat(int[] registers) throws IllegalArgumentException
{
if (registers.length != 2)
throw new IllegalArgumentException("Input Array length invalid");
int highRegister = registers[1];
int lowRegister = registers[0];
byte[] highRegisterBytes = toByteArray(highRegister);
byte[] lowRegisterBytes = toByteArray(lowRegister);
byte[] floatBytes = {
highRegisterBytes[1],
highRegisterBytes[0],
lowRegisterBytes[1],
lowRegisterBytes[0]
};
return ByteBuffer.wrap(floatBytes).getFloat();
}
Any help to do it in flutter / dart?

Answer 1

This can be done with bit shifts and a bitwise or. You need to shift the 2 higher bytes by 16 bits, then or it to get the value you want.
void main() {
List<int> vals = [22136, 4660];
int result = vals[1] << 16 | vals[0];
print(result);//305419896
}
You could also achieve the same result in this case by replacing the bitwise or with addition.
void main() {
List<int> vals = [22136, 4660];
int result = (vals[1] << 16) + vals[0];
print(result);//305419896
}