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--- exploring_lora [2018/09/29 11:43] – [3.1. Modifying the Radio Parameters] samer
+++ exploring_lora [2018/09/29 12:59] – [3.1. Modifying the Radio Parameters] samer
@@ Line 67: / Line 67: @@
 ==== -. Modifying the Radio Parameters ====
 Download the {{ :sketch-1819.zip | basic sketches}} that implement a simple LoRa communication between the two modules: a client module and a server module. Open the sketches with Arduino IDE. Make sure to choose the correct ''Board'' and ''Port'' in the ''Tools'' menu.
-Start by setting the central frequency of your LoRa modules according to the following table:
+Take a look at the source code in ''rf95_client.ino'' and ''rf95_server.ino''. Particularly, the ''setup'' function configures the radio parameters of your LoRa devices:
+  * Central frequency (freq)
+  * Spreading Factor (SF)
+  * Bandwidth (Bw)
+  * Coding Rate (CR)
+  * Transmit power (Pow)
+<code c++>
+rf95.setFrequency(frequency);
+// Setup Power,dBm
+rf95.setTxPower(13);
+// Setup Spreading Factor (6 ~ 12)
+rf95.setSpreadingFactor(7);
+// Setup BandWidth, option: 7800,10400,15600,20800,31250,41700,62500,125000,250000,500000
+//Lower BandWidth for longer distance.
+rf95.setSignalBandwidth(125000);
+// Setup Coding Rate:5(4/5),6(4/6),7(4/7),8(4/8)
+rf95.setCodingRate4(5);
+</code>
+In order to reduce collisions, configure the central frequency of your LoRa modules as indicated below:
 ^  Group Number  ^   Frequency     ^
@@ Line 84: / Line 108: @@
 |       11       |      868.7      |
 |       12       |      868.9      |
-The typical configuration for LoRa modules consists of 125 kHz sub-channels, a coding rate of 4/5, and a spreading factor equal to 7. You can also modify these radio parameters in the ''setup'' function.
 ==== -. Running Basic Sketches ====
-Download the {{ :sketch-1819.zip | basic sketches}} that implement a simple LoRa communication between the two modules. Open the sketches with Arduino IDE, compile and upload on the two arduino modules, respectively. On the serial interfaces, you should obtain similar results as in Fig. 2 and Fig. 3. The client sends periodically a short message and towards the server. The server outputs the RSSI (received power in dBm) for each received message.
+Now you can compile and upload the client and server sketches on the two arduino modules, respectively. On the serial interfaces, you should obtain similar results as in Fig. 2 and Fig. 3. The client sends periodically a short message towards the server. The server outputs the RSSI (received power in dBm) for each received message.
 [{{ :client-iotlab1.png?direct&600 ||Figure 2. Client serial monitor}}]