diff --git a/bsp_q7s/boardtest/Q7STestTask.cpp b/bsp_q7s/boardtest/Q7STestTask.cpp
index 6a0dc690..51ba99d2 100644
--- a/bsp_q7s/boardtest/Q7STestTask.cpp
+++ b/bsp_q7s/boardtest/Q7STestTask.cpp
@@ -19,9 +19,9 @@ Q7STestTask::Q7STestTask(object_id_t objectId): TestTask(objectId) {
 
 ReturnValue_t Q7STestTask::performOneShotAction() {
     //sdCardTests();
-    //testScratchApi();
+    testScratchApi();
     //testJsonLibDirect();
-    testDummyParams();
+    //testDummyParams();
     return TestTask::performOneShotAction();
 }
 
@@ -68,9 +68,21 @@ void Q7STestTask::testScratchApi() {
     }
     int number = 0;
     result = scratch::readNumber("TEST", number);
+    sif::info << "Q7STestTask::testScratchApi: Value for key \"TEST\": " << number << std::endl;
     if(result != HasReturnvaluesIF::RETURN_OK) {
         sif::debug << "Q7STestTask::scratchApiTest: Reading number failed" << std::endl;
     }
+
+    result = scratch::writeString("TEST2", "halloWelt");
+    if(result != HasReturnvaluesIF::RETURN_OK) {
+        sif::debug << "Q7STestTask::scratchApiTest: Writing string failed" << std::endl;
+    }
+    std::string string;
+    result = scratch::readString("TEST2", string);
+    if(result != HasReturnvaluesIF::RETURN_OK) {
+        sif::debug << "Q7STestTask::scratchApiTest: Reading number failed" << std::endl;
+    }
+    sif::info << "Q7STestTask::testScratchApi: Value for key \"TEST2\": " << string << std::endl;
 }
 
 void Q7STestTask::testJsonLibDirect() {
diff --git a/bsp_q7s/memory/SdCardManager.cpp b/bsp_q7s/memory/SdCardManager.cpp
index 3d309dd4..d24f540d 100644
--- a/bsp_q7s/memory/SdCardManager.cpp
+++ b/bsp_q7s/memory/SdCardManager.cpp
@@ -56,6 +56,10 @@ ReturnValue_t SdCardManager::switchOnSdCard(sd::SdCard sdCard, bool doMountSdCar
     else if(sdCard == sd::SdCard::SLOT_1) {
         targetStatus = statusPair->second;
     }
+    else {
+        // Should not happen
+        targetStatus = sd::SdStatus::OFF;
+    }
 
     auto switchCall = [&]() {
         if(targetStatus == sd::SdStatus::ON) {
diff --git a/bsp_q7s/memory/scratchApi.cpp b/bsp_q7s/memory/scratchApi.cpp
index 0b159775..08d59df1 100644
--- a/bsp_q7s/memory/scratchApi.cpp
+++ b/bsp_q7s/memory/scratchApi.cpp
@@ -5,7 +5,44 @@ ReturnValue_t scratch::writeString(std::string name, std::string string) {
     oss << "xsc_scratch write " << name << " \"" << string << "\"";
     int result = std::system(oss.str().c_str());
     if(result != 0) {
-        utility::handleSystemError(result, "scratch::String");
+        utility::handleSystemError(result, "scratch::writeString");
+        return HasReturnvaluesIF::RETURN_FAILED;
+    }
+    return HasReturnvaluesIF::RETURN_OK;
+}
+
+ReturnValue_t scratch::readString(std::string key, std::string &string) {
+    std::ifstream file;
+    std::string filename;
+    ReturnValue_t result = readToFile(key, file, filename);
+    if(result != HasReturnvaluesIF::RETURN_OK) {
+        return result;
+    }
+
+    std::string line;
+    if (not std::getline(file, line)) {
+        std::remove(filename.c_str());
+        return HasReturnvaluesIF::RETURN_FAILED;
+    }
+
+    size_t pos = line.find("=");
+    if(pos == std::string::npos) {
+        sif::warning << "scratch::readNumber: Output file format invalid, "
+                "no \"=\" found" << std::endl;
+        // Could not find value
+        std::remove(filename.c_str());
+        return KEY_NOT_FOUND;
+    }
+    string = line.substr(pos + 1);
+    return HasReturnvaluesIF::RETURN_OK;
+}
+
+ReturnValue_t scratch::clearValue(std::string key) {
+    std::ostringstream oss;
+    oss << "xsc_scratch clear " << key;
+    int result = std::system(oss.str().c_str());
+    if(result != 0) {
+        utility::handleSystemError(result, "scratch::clearValue");
         return HasReturnvaluesIF::RETURN_FAILED;
     }
     return HasReturnvaluesIF::RETURN_OK;
diff --git a/bsp_q7s/memory/scratchApi.h b/bsp_q7s/memory/scratchApi.h
index 866f1035..4f3dcd60 100644
--- a/bsp_q7s/memory/scratchApi.h
+++ b/bsp_q7s/memory/scratchApi.h
@@ -22,26 +22,54 @@ static constexpr char PREFERED_SDC_KEY[] = "PREFSD";
 static constexpr uint8_t INTERFACE_ID = CLASS_ID::SCRATCH_BUFFER;
 static constexpr ReturnValue_t KEY_NOT_FOUND = HasReturnvaluesIF::makeReturnCode(INTERFACE_ID, 0);
 
+ReturnValue_t clearValue(std::string key);
+
+/**
+ * Write a string to the scratch buffer
+ * @param key
+ * @param string    String to write
+ * @return
+ */
+ReturnValue_t writeString(std::string key, std::string string);
+/**
+ * Read a string from the scratch buffer
+ * @param key
+ * @param string    Will be set to read string
+ * @return
+ */
+ReturnValue_t readString(std::string key, std::string& string);
+
+/**
+ * Write a number to the scratch buffer
+ * @tparam T
+ * @tparam
+ * @param key
+ * @param num   Number. Template allows to set signed, unsigned and floating point numbers
+ * @return
+ */
+template<typename T, class = typename std::enable_if<std::is_integral<T>::value>::type>
+inline ReturnValue_t writeNumber(std::string key, T num) noexcept;
+
+/**
+ * Read a number from the scratch buffer.
+ * @tparam T
+ * @tparam
+ * @param name
+ * @param num
+ * @return
+ */
+template<typename T, class = typename std::enable_if<std::is_integral<T>::value>::type>
+inline ReturnValue_t readNumber(std::string key, T& num) noexcept;
+
+
+// Anonymous namespace
 namespace {
+
 static uint8_t counter = 0;
-}
 
-template<typename T, class = typename std::enable_if<std::is_integral<T>::value>::type>
-inline ReturnValue_t writeNumber(std::string name, T num) noexcept {
-    std::ostringstream oss;
-    oss << "xsc_scratch write " << name << " " << std::to_string(num);
-    int result = std::system(oss.str().c_str());
-    if(result != 0) {
-        utility::handleSystemError(result, "scratch::writeNumber");
-        return HasReturnvaluesIF::RETURN_FAILED;
-    }
-    return HasReturnvaluesIF::RETURN_OK;
-}
-
-template<typename T, class = typename std::enable_if<std::is_integral<T>::value>::type>
-inline ReturnValue_t readNumber(std::string name, T& num) noexcept {
+ReturnValue_t readToFile(std::string name, std::ifstream& file, std::string& filename) {
     using namespace std;
-    string filename = "/tmp/sro" + std::to_string(counter++);
+    filename = "/tmp/sro" + std::to_string(counter++);
     ostringstream oss;
     oss << "xsc_scratch read " << name << " > " << filename;
 
@@ -59,9 +87,38 @@ inline ReturnValue_t readNumber(std::string name, T& num) noexcept {
             return HasReturnvaluesIF::RETURN_FAILED;
         }
     }
-    ifstream file(filename);
+    file.open(filename);
+    return HasReturnvaluesIF::RETURN_OK;
+}
+
+} // End of anonymous namespace
+
+template<typename T, class = typename std::enable_if<std::is_integral<T>::value>::type>
+inline ReturnValue_t writeNumber(std::string key, T num) noexcept {
+    std::ostringstream oss;
+    oss << "xsc_scratch write " << key << " " << std::to_string(num);
+    int result = std::system(oss.str().c_str());
+    if(result != 0) {
+        utility::handleSystemError(result, "scratch::writeNumber");
+        return HasReturnvaluesIF::RETURN_FAILED;
+    }
+    return HasReturnvaluesIF::RETURN_OK;
+}
+
+template<typename T, class = typename std::enable_if<std::is_integral<T>::value>::type>
+inline ReturnValue_t readNumber(std::string key, T& num) noexcept {
+    using namespace std;
+    ifstream file;
+    std::string filename;
+    ReturnValue_t result = readToFile(key, file, filename);
+    if(result != HasReturnvaluesIF::RETURN_OK) {
+        std::remove(filename.c_str());
+        return result;
+    }
+
     string line;
     if (not std::getline(file, line)) {
+        std::remove(filename.c_str());
         return HasReturnvaluesIF::RETURN_FAILED;
     }
 
@@ -85,8 +142,6 @@ inline ReturnValue_t readNumber(std::string name, T& num) noexcept {
     return HasReturnvaluesIF::RETURN_OK;
 }
 
-ReturnValue_t writeString(std::string name, std::string string);
-
 }
 
 #endif /* BSP_Q7S_MEMORY_SCRATCHAPI_H_ */