diff --git a/lib/session/StreamingMsgPackEncoder.h b/lib/session/StreamingMsgPackEncoder.h
index 59a7c85..b92ba0a 100644
--- a/lib/session/StreamingMsgPackEncoder.h
+++ b/lib/session/StreamingMsgPackEncoder.h
@@ -245,7 +245,7 @@ private:
             return;
         }
 
-        if( sentBytes_ + sizeRequired < maxBytes_ ) {
+        if( sentBytes_ + sizeRequired <= maxBytes_ ) {
             sendFunction();
             sentBytes_ += sizeRequired;
         } else {
diff --git a/readme b/readme
new file mode 100644
index 0000000..9627eb8
--- /dev/null
+++ b/readme
@@ -0,0 +1,6 @@
+
+Run tests:
+    pio test -v -e native
+
+Compile and upload:
+    pio run -e d1 -t upload
\ No newline at end of file
diff --git a/src/config.h b/src/config.h
deleted file mode 100644
index 0c8d400..0000000
--- a/src/config.h
+++ /dev/null
@@ -1,9 +0,0 @@
-
-
-
-// Measurement parameters
-const int DELAY = 100;                // interval in ms between measurements
-const int SESSION_SIZE = 1024*8;      // how many data points are added to the session
-const byte MEASUREMENT_AVG_COUNT = 1; // averages over this many consecutive AD-converter reads
-const byte TARE_AVG_COUNT = 50;       // number of measurements in tare-phase (to find 0 )
-const int DIVIDER = 128;              // uint32 measurements are divided by this factor, before stored in uint16_t
diff --git a/src/firmware_main.cpp b/src/firmware_main.cpp
index 42f8971..ba3f250 100644
--- a/src/firmware_main.cpp
+++ b/src/firmware_main.cpp
@@ -34,18 +34,22 @@ public:
     void begin() {
         scale.begin(CONFIG_SCALE_DOUT_PIN, CONFIG_SCALE_SCK_PIN);
         scale.tare( CONFIG_TARE_AVG_COUNT );
-
         session.init( timeClient.getEpochTime() );
     }
 
     void startMeasurements() {
         measuring_ = true;
+        session.init( timeClient.getEpochTime() );
     }
 
     void stopMeasurements() {
         measuring_ = false;
     }
 
+    bool isMeasuring() const {
+        return measuring_;
+    }
+
     void iteration() {
         if( ! measuring_ ) {
             return;
diff --git a/test/test_common/sessiontest.cpp b/test/test_common/sessiontest.cpp
index 86f1359..bfceac3 100644
--- a/test/test_common/sessiontest.cpp
+++ b/test/test_common/sessiontest.cpp
@@ -4,6 +4,7 @@
 #include "MockStorage.h"
 #include <unity.h>
 #include <vector>
+#include <iostream>
 
 template<typename Measurement_T>
 std::vector<Measurement_T> parseMessagePack(const uint8_t * data, uint32_t &startTime, uint32_t &startIndex)
@@ -188,9 +189,28 @@ void testPartialSessionSerialization() {
     }
 }
 
+void testPartialSessionSerializationEmptyArray() {
+    const uint32_t SESSION_SIZE = 1024*8 - 16 * sizeof(uint32_t);
+    typedef MeasurementSession<uint16_t, MockStorageReader, MockStorageWriter, SESSION_SIZE> MockSession;
+
+    const uint32_t startTime = 194842;
+    const uint_t fillSize = 4937 + 81;
+
+    std::vector<uint8_t> data;
+    VectorAdaptor adaptor( &data );
+
+    MockSession session;
+    session.init(startTime);
+    ChunkedStreamingMsgPackEncoder<VectorAdaptor> encoder(&adaptor, 0, 6);
+    session.serialize(encoder, 0);
+    auto written = encoder.sentBytes();
+    TEST_ASSERT(written == 6);
+}
+
 void allTests()
 {
     UNITY_BEGIN();
+    RUN_TEST(testPartialSessionSerializationEmptyArray);
     RUN_TEST(testPartialSessionSerialization);
     RUN_TEST(testSessionChunkAdd);
     RUN_TEST(testSessionChunkGetterSetter);