Improve on random()

README.md

@@ -1,9 +1,11 @@
 # Arduino LoRa
 
-[![Build Status](https://travis-ci.org/sandeepmistry/arduino-LoRa.svg?branch=master)](https://travis-ci.org/sandeepmistry/arduino-LoRa)
+[![Build Status](https://travis-ci.org/WereCatf/arduino-LoRa.svg?branch=master)](https://travis-ci.org/github/WereCatf/arduino-LoRa)
 
 An [Arduino](https://arduino.cc/) library for sending and receiving data using [LoRa](https://www.lora-alliance.org/) radios.
 
+**This is a fork of [Sandeep Mistry's awesome library](https://github.com/sandeepmistry/arduino-LoRa) with the only meaningful change being a more useful and easier-to-use random() - function.**
+
 ## Compatible Hardware
 
  * [Semtech SX1276/77/78/79](https://www.semtech.com/apps/product.php?pn=SX1276) based boards including:
@@ -12,7 +14,7 @@ An [Arduino](https://arduino.cc/) library for sending and receiving data using [
    * [Modtronix](http://modtronix.com/) [inAir4](http://modtronix.com/inair4.html), [inAir9](http://modtronix.com/inair9.html), and [inAir9B](http://modtronix.com/inair9b.html)
  * [Arduino MKR WAN 1300](https://store.arduino.cc/usa/mkr-wan-1300)
    * **NOTE:** Requires firmware v1.1.6 or later on the on-board Murata module. Please use the [MKRWANFWUpdate_standalone example](https://github.com/arduino-libraries/MKRWAN/blob/master/examples/MKRWANFWUpdate_standalone/MKRWANFWUpdate_standalone.ino) from latest [MKRWAN library](https://github.com/arduino-libraries/MKRWAN) release to update the firmware.
-   * **WARNING**: [LoRa.onReceive(...)](https://github.com/sandeepmistry/arduino-LoRa/blob/master/API.md#register-callback) and [LoRa.recieve()](https://github.com/sandeepmistry/arduino-LoRa/blob/master/API.md#receive-mode) is not compatible with this board!
+   * **WARNING**: [LoRa.onReceive(...)](https://github.com/WereCatf/arduino-LoRa/blob/master/API.md#register-callback) and [LoRa.recieve()](https://github.com/WereCatf/arduino-LoRa/blob/master/API.md#receive-mode) is not compatible with this board!
 
 ### Semtech SX1276/77/78/79 wiring
 
@@ -47,7 +49,7 @@ An [Arduino](https://arduino.cc/) library for sending and receiving data using [
 
 ```sh
 cd ~/Documents/Arduino/libraries/
-git clone https://github.com/sandeepmistry/arduino-LoRa LoRa
+git clone https://github.com/WereCatf/arduino-LoRa LoRa
 ```
 
 ## API

library.properties

@@ -1,10 +1,10 @@
 name=LoRa
 version=0.8.0
-author=Sandeep Mistry <sandeep.mistry@gmail.com>
-maintainer=Sandeep Mistry <sandeep.mistry@gmail.com>
+author=WereCatf <werecatf@runbox.com>
+maintainer=WereCatf <werecatf@runbox.com>
 sentence=An Arduino library for sending and receiving data using LoRa radios.
 paragraph=Supports Semtech SX1276/77/78/79 based boards/shields.
 category=Communication
-url=https://github.com/sandeepmistry/arduino-LoRa
+url=https://github.com/WereCatf/arduino-LoRa
 architectures=*
 includes=LoRa.h

src/LoRa.cpp

@@ -645,7 +645,43 @@ void LoRaClass::setGain(uint8_t gain)
 
 byte LoRaClass::random()
 {
-  return readRegister(REG_RSSI_WIDEBAND);
+  uint8_t currMode = readRegister(REG_OP_MODE);
+  uint8_t retVal = 0, bits=7;
+  void (*_prevOnReceive)(int) = NULL;
+
+  while(isTransmitting()) yield();
+
+  //We need to be listening to radio-traffic in order to generate random numbers
+  if(currMode != (MODE_LONG_RANGE_MODE | MODE_RX_CONTINUOUS)){
+#ifndef ARDUINO_SAMD_MKRWAN1300
+    _prevOnReceive = _onReceive;
+    onReceive(NULL);
+    receive();
+#else
+    explicitHeaderMode();
+    writeRegister(REG_OP_MODE, MODE_LONG_RANGE_MODE | MODE_RX_CONTINUOUS);
+#endif
+    delay(1);
+    }
+  retVal = readRegister(REG_RSSI_WIDEBAND);
+  while(bits--) {
+    retVal<<=1;
+    while(1){
+      // implement a basic von Neumann Extractor
+      uint8_t a=(readRegister(REG_RSSI_WIDEBAND) & 1);
+      if(a != (readRegister(REG_RSSI_WIDEBAND) & 1)){
+        // put random, whitened bit in n
+        retVal |= a;
+        break;
+      }
+    }
+  }
+  //Put the radio in the same mode as it was
+  if(currMode != (MODE_LONG_RANGE_MODE | MODE_RX_CONTINUOUS)) writeRegister(REG_OP_MODE, currMode);
+#ifndef ARDUINO_SAMD_MKRWAN1300
+  if(_prevOnReceive) onReceive(_prevOnReceive);
+#endif
+  return retVal;
 }
 
 void LoRaClass::setPins(int ss, int reset, int dio0)