From be747b2cea89f7dc7fb9cb8915cbb9f75c0583b9 Mon Sep 17 00:00:00 2001
From: Joe Finney <joe@comp.lancs.ac.uk>
Date: Fri, 20 Jan 2017 23:56:08 +0000
Subject: [PATCH] Add support for Random Number Generator initialisation #9

- Update API to allow allow definition of per device RNG seed
- Update to AnalogSensor to create a valid initial sample on creation.
---
 inc/core/CodalDevice.h          | 11 +++++++----
 source/drivers/AnalogSensor.cpp |  1 +
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/inc/core/CodalDevice.h b/inc/core/CodalDevice.h
index 5276f18..cfadff1 100644
--- a/inc/core/CodalDevice.h
+++ b/inc/core/CodalDevice.h
@@ -46,6 +46,8 @@ class CodalDevice
       */
     CodalDevice()
     {
+        if (random_value == 0)
+            random_value = 0xC0DA1;
     }
 
     /**
@@ -99,12 +101,13 @@ class CodalDevice
     /**
      * Seed the random number generator (RNG).
      *
-     * default: 0xCAFECAFE
-     * @return an unsigned 32 bit seed to seed codal's lightweight Galois LFSR.
+     * @param seed an unsigned 32 bit value used to seed codal's lightweight Galois LFSR.
+     * @return DEVICE_OK on success
      */
-    virtual uint32_t seedRandom()
+    virtual int seedRandom(uint32_t seed)
     {
-        return 0xCAFECAFE;
+        random_value = seed;
+        return DEVICE_OK;
     }
 };
 
diff --git a/source/drivers/AnalogSensor.cpp b/source/drivers/AnalogSensor.cpp
index 4fa1e4a..123ef7b 100644
--- a/source/drivers/AnalogSensor.cpp
+++ b/source/drivers/AnalogSensor.cpp
@@ -55,6 +55,7 @@ AnalogSensor::AnalogSensor(DevicePin &pin, uint16_t id) : _pin(pin)
         EventModel::defaultEventBus->listen(id, ANALOG_SENSOR_UPDATE_NEEDED, this, &AnalogSensor::onSampleEvent, MESSAGE_BUS_LISTENER_IMMEDIATE);
 
     setPeriod(500);
+    updateSample();
 }
 
 /*