如何取得無人機發射機上的 RSSI 和 SNR?
目錄
題: 我注意到TX900網頁不會向飛控發送RSSI數據; 當無線電鏈路遺失時，它不會觸發故障保護操作. 有什麼辦法可以解決這個問題?
回答: 客戶需要RSSI無線鏈路狀態數據 (例如飛行控制器) 手動發送AT指令獲取. 可以透過兩種方式獲得:
- 配置UART3 (數據連接埠第三) 作為AT指令串口, 然後透過UART3發送AT指令 (D3) 獲得. https://ivcan.com/change-d3-from-transparent-serial-port-to-at-command/
- 更新韌體版本 1.5.1 以上, 這樣內部就會多一個TCP伺服器，讓客戶透過TCP存取發送AT命令取得無線狀態.
這是我們工程師的解釋.
- LED燈用於指示無線連線狀態 (例如, 如果無線連結斷開, 燈將會熄滅), 並且沒有專門的外部引腳通知客戶飛控.
- 我們的核心模組有 GPIO 引腳, 但它們基本上都是連接LED燈的. 我們的vcan1681模組也有這樣的腳, 但目前, 它還連接到 LED 燈.
- 如果你願意花錢定制, 我們可以為您訂製一款特別的, 並且可以改變外部介面.
- 當客戶使用我們的無人機無線視訊資料鏈路時, 他們肯定需要透過串口或網口轉串口來獲取空側飛控訊息.
- 一般的方法是在地面站軟體和飛控軟體中添加驗證來衡量無線鏈路的可靠性. 此時, 您可以在軟體中完全感知鏈路品質和鏈路斷開事件, 然後在軟體中設定閾值進行警報處理.
- 也就是說, 當地面站軟體透過我們的無線鏈路獲取空中系統飛控資訊時如果錯誤率超過一定閾值, 可以認為無線鏈路已經達到不可靠閾值，需要處理. 這是中國無人機企業的普遍做法.
談論以下產品的 RSSI SNR
題: 你能為我開發一個新模型嗎? 很容易得到RSSI和SNR?
您是否只需要取得無線連結是否連接/斷開的即時狀態? 或者我們是否需要獲得 RSSI?
因為一個GPIO只能辨識兩種狀態: 0/1, 只能用於指示無線鏈路是否連接/斷開, 並且無法表達RSSI的值 (RSSI和SNR的值仍然需要透過AT指令取得)
如果您需要我們除了連結連線/斷線狀態之外，還主動回報RSSI、SNR等訊息, 那就必須按照客製化的項目進行操作. 您需要清楚地描述您的需求, 對接介面, 等等. (而不是用一個簡單的句子), 以便我們評估客製化開發的難度以及實現途徑.
What is SNR and RSSI?
SNR (Signal-to-Noise Ratio) is a ratio-based metric that measures your signal in relation to the noise.SNR is made up of two values that are measured as a positive number between 0db and 120db, with the closer it is to 120db, the better: signal value and noise value, both of which are commonly reported in decibels (分貝).
該接收信號強度指數 (Received signal strength indication) will look at the Signal (Also known as RSSI) first this value is measured in decibels from 0 (zero) 至 -120 (minus 120) now when looking at this value the closer to 0 (zero) the stronger the signal is which means it’s better, typically voice networks require a -65db or better signal level while a data network requires -80db or better.
Because the signal is affected by the AP’s transmit power and antenna, as well as the client’s antenna, the normal range in a network would be -45db to -87db depending on power levels and design.
Signal strength (接收信號強度指數, “signal strength”, Signal/Noise Ratio). It is often preferable to concentrate on RSSI.
- 接收信號強度指數 -90 dBm的: This signal is incredibly faint, and it is at the limit of what a receiver can receive.
- RSSI -67dBm indicates a rather strong signal.
- RSSI greater than -55dBm indicates a very strong signal.
- 接收信號強度指數 > -30dBm indicates that your sniffer is right adjacent to the emitter.
Failsafe
題: In case of signal loss from the operator, will FailSafe be activated?
回答: Failsafe is the function of the flight controller. We just provide signal transmission and transmit transparent data. What data do you give us, We transmit them for you.
題: Unless your receiver reports that the connection is lost, FailSafe is not activated.
回答: You can get the signal strength. Our wireless video data transmitter and receiver don’t have this function. I believe that the wireless image transmission of Chinese suppliers does not have this function, except that the drone set has already the failsafe function.