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gocastingmodbus

How to convert a sequence of uint16 to float32?

I've a sequence [66 106 179 86](those numbers are two 16bit register in modbus) generated by modbus library(conversion code), now how can I convert this sequence in a 32 float number?

I've tried []uint32{66,106, 179, 86} as argument for Float32frombits but doesn't accept uint32 lists.

Solution

  • Using math.Float32fromBits()

    We may use math.Float32fromBits() to obtain a float32 value from its "binary" representation. But in order to use it, we need the 4 bytes data packed into a uint32 value. For that, we may use binary.ByteOrder.Uint32():

    data := []byte{66, 106, 179, 86}

bits := binary.BigEndian.Uint32(data)
f := math.Float32frombits(bits)
fmt.Println(f)

    Output (try it on the Go Playground):

    58.675133

    This solution is faster if we just want to read a single float32 value.

    Using binary.Read()

    Another option would be to use binary.Read() to fill fixed-size values from an io.Reader. If we have our data as a byte slice, we can use bytes.NewBuffer() to obtain an io.Reader from it:

    data := []byte{66, 106, 179, 86}
var f float32
err := binary.Read(bytes.NewBuffer(data), binary.BigEndian, &f)
fmt.Println(f, err)

    Output (try it on the Go Playground):

    58.675133 <nil>

    This solution is preferred if we have to read a series of float32 values from the input.