# 通訊模組與 Payload 試算

* SF=7, bandwith=125kHz, CR=1 => 5468bit/s
* SF=7, bandwith=500kHz, CR=1 => 21875 bit/s

## Payload 試算

{
    ax,
    ay,
    az,
    deg-ax,
    deg-ay,
    deg-az,
    height(氣壓數值),
    GPS-經度,// 64 bit !
    GPS-緯度,// 64 bit !
    GPS-高度,// 64 bit !
    pressure,
    Temperature,
    humidity,
    Temperature-High-1,
    Temperature-High-2,
    Temperature-High-3,
    電池電壓,
    5V電壓,
}

15 * 32bit + 3 * 64 = 672bit

6*32=192

192*20=3840bit/s

5468bit-3840bit=

672bit * 20 = 13440bit/s

## Link budge 計算

https://www.everythingrf.com/rf-calculators/link-budget-calculator