diff --git a/lambda-test/avrjunit.h b/lambda-test/avrjunit.h
index cfb844a..12a3b2b 100644
--- a/lambda-test/avrjunit.h
+++ b/lambda-test/avrjunit.h
@@ -4,9 +4,23 @@
  *  Created on: 06.03.2015
  *      Author: dode@luniks.net
  */
+
+/**
+ * A test case with its name and pointer to the test function,
+ * which should return true on success and false on failure.
+ */
 typedef struct {
 	char* name;
 	int (*test)(void);
 } test;
 
+/**
+ * Runs the test cases in the given array and prints the results
+ * via USART in JUnit XML format, using the given test suite and
+ * test class names. The size of the array needs to be passed
+ * along.
+ * The printed JUnit XML can be read and written to a file
+ * on the receiving side with a command like:
+ * (stty sane; cat > tests.xml) < /dev/ttyUSB0
+ */
 void runTests(char* suite, char* class, test tests[], int count);
diff --git a/lambda-test/lambda-test.c b/lambda-test/lambda-test.c
index 832787d..077a6f1 100644
--- a/lambda-test/lambda-test.c
+++ b/lambda-test/lambda-test.c
@@ -5,40 +5,82 @@
  *      Author: dode@luniks.net
  *
  */
+#include <math.h>
 #include <stdio.h>
+// #include <stdlib.h>
 #include "USART.h"
 #include "sensors.h"
 #include "avrjunit.h"
 
+static const tableEntry testTable[] = {
+		{0, 0},
+		{10, 10}
+};
+
+int testToLambdaValue(void) {
+	float lambda = toLambda(12);
+
+	return lambda == 1.5;
+}
+
+int testToLambdaInter(void) {
+	float lambda = toLambda(50);
+
+	return round(lambda * 1000) == 1073;
+}
+
 int testToTempI(void) {
 	int temp = toTempI(100);
 
 	return temp == 20;
 }
 
-int testToTempO0C(void) {
+int testToTempOValue(void) {
 	int temp = toTempO(454);
 
 	return temp == 0;
 }
 
-int testToTempO50C(void) {
+int testToTempOInter(void) {
 	int temp = toTempO(928);
 
 	return temp == 50;
 }
 
-int testToTempO100C(void) {
-	int temp = toTempO(1403);
+int testLookupLinInterBelow(void) {
+	float value = lookupLinInter(-5, testTable, 2);
 
-	return temp == 100;
+	return value == 0;
+}
+
+int testLookupLinInterAbove(void) {
+	float value = lookupLinInter(15, testTable, 2);
+
+	return value == 10;
+}
+
+int testLookupLinInterValue(void) {
+	float value = lookupLinInter(10, testTable, 2);
+
+	return value == 10;
+}
+
+int testLookupLinInterInter(void) {
+	float value = lookupLinInter(3, testTable, 2);
+
+	return value == 3;
 }
 
 test tests[] = {
-	{"testToTempI", testToTempI},
-	{"testToTempO0C", testToTempO0C},
-	{"testToTempO50C", testToTempO50C},
-	{"testToTempO100C", testToTempO100C}
+		{"testToLambdaValue", testToLambdaValue},
+		{"testToLambdaInter", testToLambdaInter},
+		{"testToTempI", testToTempI},
+		{"testToTempOValue", testToTempOValue},
+		{"testToTempOInter", testToTempOInter},
+		{"testLookupLinInterValue", testLookupLinInterValue},
+		{"testLookupLinInterInter", testLookupLinInterInter},
+		{"testLookupLinInterBelow", testLookupLinInterBelow},
+		{"testLookupLinInterAbove", testLookupLinInterAbove}
 };
 
 int main(void) {