implement minimum rssi filtering (#482)

docs/use/ble.md

@@ -72,6 +72,20 @@ you can also force a scan to be done by the following command:
 
 Once done the previous value of interval will be recovered.
 
+The default value is set into config_BT.h
+
+## Setting the minimum RSSI accepted to publish device data
+
+If you want to change the minimum RSSI value accepted for a device to be published, you can change it by MQTT. For example if you want to set -80
+
+`mosquitto_pub -t home/OpenMQTTGateway/commands/MQTTtoBT/set -m '{"minrssi":-80}'`
+
+you can also accept all the devices by the following command:
+
+`mosquitto_pub -t home/OpenMQTTGateway/commands/MQTTtoBT/set -m '{"minrssi":0}'`
+
+The default value is set into config_BT.h
+
 ## Other
 
 To check your hm10 firmware version upload a serial sketch to the nodemcu (this will enable communication directly with the hm10) and launch the command:

main/ZgatewayBT.ino

@@ -319,9 +319,6 @@ void MiBandDiscovery(char * mac){
     #include "soc/timer_group_struct.h"
     #include "soc/timer_group_reg.h"
     
-    //Time used to wait for an interval before resending BLE infos
-    unsigned long timeBLE= 0;
-    
     //core on which the BLE detection task will run
     static int taskCore = 0;
       
@@ -370,6 +367,7 @@ void MiBandDiscovery(char * mac){
                   BLEdata.set("servicedata", service_data);  
                 #endif
                 BLEdata.set("servicedatauuid", (char *)advertisedDevice.getServiceDataUUID(j).toString().c_str());
+                if(abs((int)BLEdata["rssi"]|0) < abs(Minrssi)) { // publish only the devices close enough
                   pub((char *)mactopic.c_str(),BLEdata);
                   if (strstr(BLEdata["servicedatauuid"].as<char*>(),"fe95") != NULL){ //Mi FLora, Mi jia, Cleargrass, LYWDS02
                     trc("Processing BLE device data");
@@ -447,9 +445,16 @@ void MiBandDiscovery(char * mac){
                       #endif
                       process_miband(service_data,mac);
                   }
+                }else{
+                  trc("Low rssi, device filtered");
+                }
               }
           }else{
+            if(abs((int)BLEdata["rssi"]|0) < abs(Minrssi)) { // publish only the devices close enough
               pub((char *)mactopic.c_str(),BLEdata); // publish device even if there is no service data
+            }else{
+              trc("Low rssi, device filtered");
+            }
           }
         }else{
           trc(F("Filtered mac device"));
@@ -487,8 +492,11 @@ void MiBandDiscovery(char * mac){
   
     void setupBT(){
       BLEinterval = TimeBtw_Read;
+      Minrssi = MinimumRSSI;
       trc(F("BLEinterval btw scans"));
       trc(BLEinterval);
+      trc(F("Minrssi"));
+      trc(Minrssi);
       // we setup a task with priority one to avoid conflict with other gateways
       xTaskCreatePinnedToCore(
                         coreTask,   /* Function to implement the task */
@@ -524,8 +532,11 @@ void MiBandDiscovery(char * mac){
     
     void setupBT() {
       BLEinterval = TimeBtw_Read;
+      Minrssi = MinimumRSSI;
       trc(F("BLEinterval btw scans"));
       trc(BLEinterval);
+      trc(F("Minrssi"));
+      trc(Minrssi);
       softserial.begin(9600);
       softserial.print(F("AT+ROLE1"));
       delay(100);
@@ -603,6 +614,7 @@ void MiBandDiscovery(char * mac){
                   #ifdef pubBLEServiceData
                     BLEdata.set("servicedata", (char *)service_data.c_str());
                   #endif
+                  if(abs((int)BLEdata["rssi"]|0) < abs(Minrssi)) { // publish only the devices close enough
                     pub((char *)topic.c_str(),BLEdata);
                     int pos = -1;
                     pos = strpos(d[5].extract,"209800");
@@ -663,6 +675,9 @@ void MiBandDiscovery(char * mac){
                       process_milamp((char *)service_data.c_str(),d[0].extract);
                     }
                     return true;
+                  }else{
+                    trc("Low rssi, device filtered");
+                  }
                 }
               }
             }
@@ -908,6 +923,17 @@ void MQTTtoBT(char * topicOri, JsonObject& BTdata) { // json object decoding
         BLEinterval = prevBLEinterval; // as 0 was just used as a command we recover previous scan duration
       }
     }
+    // MinRSSI set
+    if (BTdata.containsKey("minrssi")){
+      trc(F("Min RSSI"));
+      // storing Min RSSI for further use if needed
+      trc("previous Minrssi");
+      trc(Minrssi); 
+      // set Min RSSI if present if not setting default value
+      Minrssi = (unsigned int)BTdata["minrssi"];
+      trc("new Minrssi");
+      trc(Minrssi);
+    }
   }
 }
 

main/config_BT.h

@@ -33,6 +33,7 @@ extern void MQTTtoBT(char * topicOri, JsonObject& RFdata);
 #define subjectBTtoMQTT  Base_Topic Gateway_Name "/BTtoMQTT/"
 #define subjectMQTTtoBTset  Base_Topic Gateway_Name "/commands/MQTTtoBT/set"
 #define TimeBtw_Read 55555 //define default time between 2 scans
+#define MinimumRSSI -90 //default minimum rssi value, all the devices below -90 will not be reported
 #define Scan_duration 10 //define the time for a scan
 #define HM-10
 //#define HM-11 // uncomment this line if you use HM-11 and comment the line above
@@ -45,6 +46,7 @@ extern void MQTTtoBT(char * topicOri, JsonObject& RFdata);
 #define subjectHomePresence Base_Topic "home_presence/" Gateway_Name // will send Home Assistant room presence message to this topic (first part is same for all rooms, second is room name)
 
 unsigned int BLEinterval ; //time between 2 scans
+int Minrssi ; //minimum rssi value
 
 struct BLEdevice{
   char macAdr[13];