1. Test purpose
Received Signal Strength Indicator (RSSI) is a measurement of the power level of the received radio signal.
The RXTX test allows user to establish a communication between emitter and receiver and to measure & display dynamically RRSI on a chart.
2. Explaining the dashboard
The RXTX dashboard is divided in two groups.
First group for TX transmission that allows the user to choose the RF frequency and the power level of emission (between -9 to 22 dBm). User should start and stop emission.
Second group for RX reception that allows the user to choose the RF frequency. In this group is displayed RSSI and chart that is refreshed each 250 ms. User should start and stop reception.
3. Explaining the flow
The RXTX flow is a combination of TX & RX flows. TX flow is in charge of handling emission of signal while RX flow is handling reception.
The emitter must be connected to Serial Port A. The receiver must be connected to Serial Port B.
3.1. TX flow
TX flow manages the sequence of AT commands to the emitter. A finite state machine (FSM) is used to manage the sequence of AT command and target response. The FSM status and transition are corresponding to the normal sequence of AT command and abnormal response from target is also handled. The LED indicating that the TX board is connected to the application is also managed by this flow.
3.2. RX flow
RX flow manages the sequence of AT commands to the receiver. A finite state machine (FSM) is used to manage the sequence and the target response. The chart is refreshed each 250 ms (this value could be changed in the flow with the delay node). The LED indicating that the RX board is connected to the application is also managed by this flow.
4. AT commands for PER estimation
AT commands listed below are sent to emitter and receiver
4.1. Emitter :
ATZ Reset the board
AT+TCONF[=freq:pow:bw:sf:cr:lna:pa][=868000000:14:4:12:4/5:0:0:1:16:25000:2:3] for example. Sets the config for RF test.
AT+TTONE Start the TX transmission
AT+TOFF Stop the TX transmission
4.2. Receiver:
AT+Z Reset
AT+TCONF[=freq:pow:bw:sf:cr:lna:pa][=868000000:14:4:12:4/5:0:0:1:16:25000:2:3] for example. Sets the config LoRa RF test.
AT+TRRSSI Start the RX reception and RSSI measurement
AT+TOFF Stop the RX reception