diff --git a/platformio.ini b/platformio.ini
index 7477ad7..f5ac943 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -16,6 +16,7 @@ platform = nordicnrf52@7.0.0
 board = nrf52840_dk
 framework = zephyr
 monitor_speed = 115200
+upload_protocol = jlink
 test_ignore = test_desktop
 build_flags = 
     -Iinclude/tls_config
@@ -27,6 +28,13 @@ lib_deps =
     prathje/exposure-notification @ ^0.1
 lib_ignore =
     mbedtls
+src_filter =  -<../src/main_test.c>
+
+[env:nrf52840_dk_test]
+src_filter =  -<../src/main.c>
+extends = env:nrf52840_dk
+board = nrf52840_mdk
+
 
 [env:nrf52840_mdk]
 extends = env:nrf52840_dk
diff --git a/src/main_test.c b/src/main_test.c
new file mode 100644
index 0000000..b0b664c
--- /dev/null
+++ b/src/main_test.c
@@ -0,0 +1,18 @@
+/* main.c - Application main entry point */
+
+/*
+ * Copyright (c) 2020 Olaf Landsiedel
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr.h>
+#include <sys/printk.h>
+
+
+void main(void) {
+    while(1) {
+
+        printk("Hello World!\n");
+    }
+}