-24-
v7.0
Power gain and sensitivity
Example of use:
{
sx1272.setPower(0); // Set Power Output Level to the minimum value
sx1272.getPower(); // Get Power Output Level
}
Related variables:
sx1272._power
→
stores the selected power output level
Note:
It is the responsibility of the users to know the maximum allowed power level in their country (if any), and use levels below it.
Ignoring this could lead to considerable penalties.
9.2. RSSI of one packet and RSSI of the channel
It reports the Received Signal Strength of the last received packet and the current value of the Received Signal Strength in the
selected channel. The RSSI of the packet is the meaningful one: if its value is greater than the sensitivity the packet sent is going
to be successfully detected, otherwise the packet will be lost. The RSSI of the channel reports the signal level detected in every
moment, even if it is not signal being transmitted, so it provides also noise level information. In the case the user develops a
multi-hop network, this parameters only indicate the signal strength of the last hop, so it does not provide an accurate quality
measurement of a multihop link.
Example of use:
{
sx1272.getRSSIpacket(); // Get the Receive Signal Strength Indicator
sx1272.getRSSI(); // Get the current Receive Signal Strength Indicator
}
Related variables:
sx1272._RSSIpacket
→
stores the RSSI of the last received packet
sx1272._RSSI
→
stores the current RSSI value
SX1272 RSSI example:
www.libelium.com/development/waspmote/examples/sx-12-rssilora
The ideal working mode is at getting maximum coverage with the minimum power level. Thereby, a compromise between power
level and coverage appears. Each application scenario will need some tests to find the best combination of both parameters.
9.3. SNR
It reports the Signal-to-Noise Ratio of the last received packet. The LoRa module is capable to demodulate received signals
with SNR values as low as -20 dB. Getting the SNR, it is possible to have an idea about the link’s quality or health, and thus the
additional distance we could get in a communication link.
Example of use:
{
sx1272.getSNR(); // Get the Signal Noise Ratio
}
Related Variables:
sx1272._SNR
→
stores the SNR of the last received packet
SX1272 RSSI example:
www.libelium.com/development/waspmote/examples/sx-12-rssilora
