AT+QCFG Band Calculation

main_test.go

package test

import (
	"math/big"
	"reflect"
	"strconv"
	"testing"
)

//How to calculate the band mask greater than 64 for AT+QCFG="band"
//The band mask is a 128-bit number, each bit represents a band.
// For golang , the bit > 64 need to use big.Int

func BandMask(n int) big.Int {
	mask := new(big.Int).Exp(big.NewInt(2), big.NewInt(int64(n-1)), nil)
	return *mask
}

func CombineBand(bands []string) string {
	var b big.Int
	for _, v := range bands {
		n, err := strconv.Atoi(v)
		if err != nil {
			continue
		}
		bm := BandMask(n)
		b = *new(big.Int).Add(&b, &bm)
	}

	return b.Text(16)
}

func ResolveBand(band string) []string {
	b := big.NewInt(0)
	b.SetString(band, 16)
	var bands []string
	for i := 0; i < 128; i++ {
		bi := BandMask(i)
		bband := new(big.Int).And(&bi, b)
		if bband.String() != "0" && i != 0 {
			bands = append(bands, strconv.Itoa(i))
		}
	}
	return bands
}

func Test(t *testing.T) {
	bands := []string{"1", "2", "3", "4", "5", "7", "8", "12", "13", "14", "17", "18", "19", "20", "25", "26", "28", "29", "30", "32", "34", "38", "39", "40", "41", "42", "43", "46", "48", "49", "66", "71"}
	resolveBands := ResolveBand(CombineBand(bands))
	if reflect.DeepEqual(bands, resolveBands) {
		t.Log("success")
	} else {
		t.Error("failed")
	}
}