diff --git a/tests/phydat_dump/Makefile b/tests/phydat_dump/Makefile
new file mode 100644
index 0000000000..1c1aeac913
--- /dev/null
+++ b/tests/phydat_dump/Makefile
@@ -0,0 +1,5 @@
+include ../Makefile.tests_common
+
+USEMODULE += phydat
+
+include $(RIOTBASE)/Makefile.include
diff --git a/tests/phydat_dump/main.c b/tests/phydat_dump/main.c
new file mode 100644
index 0000000000..b0c73f04a9
--- /dev/null
+++ b/tests/phydat_dump/main.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2020 Gunar Schorcht
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     tests
+ *
+ * @file
+ * @brief       Visual test for the conversion from phydat to a string
+ *
+ * @author      Gunar Schorcht <gunar@schorcht.net>
+ *
+ */
+
+#include <stdio.h>
+
+#include "phydat.h"
+
+typedef struct {
+    phydat_t dat;
+    uint8_t dim;
+} _phydat_test_t;
+
+_phydat_test_t _test_vector[] =
+{
+    { .dim = 1, .dat = { .val = { 1234 }, .unit = UNIT_TEMP_C, .scale = -2 } },
+    { .dim = 1, .dat = { .val = { 1234 }, .unit = UNIT_TEMP_F, .scale = -2 } },
+    { .dim = 1, .dat = { .val = { 1234 }, .unit = UNIT_TEMP_K, .scale = -1 } },
+    { .dim = 1, .dat = { .val = { 1234 }, .unit = UNIT_LUX, .scale = -1 } },
+    { .dim = 3, .dat = { .val = { 1234, 13456, -14567 }, .unit = UNIT_M, .scale = 0 } },
+    { .dim = 3, .dat = { .val = { 1234, 13456, -14567 }, .unit = UNIT_M, .scale = 1 } },
+    { .dim = 3, .dat = { .val = { 1234, 13456, -14567 }, .unit = UNIT_M, .scale = 3 } },
+    { .dim = 3, .dat = { .val = { 1234, 13456, -14567 }, .unit = UNIT_M, .scale = -2 } },
+    { .dim = 3, .dat = { .val = { 1234, 13456, -14567 }, .unit = UNIT_M, .scale = -3 } },
+    { .dim = 1, .dat = { .val = { -12345 }, .unit = UNIT_M2, .scale = -5 } },
+    { .dim = 1, .dat = { .val = { -12345 }, .unit = UNIT_M3, .scale = -6 } },
+    { .dim = 3, .dat = { .val = { 12, 34, 5678}, .unit = UNIT_G, .scale = -2 } },
+    { .dim = 3, .dat = { .val = { 123, 345, 678 }, .unit = UNIT_DPS, .scale = -3 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_GR, .scale = -1 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_A, .scale = 3 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_V, .scale = 6 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_W, .scale = 7 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_GS, .scale = -1 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_DBM, .scale = -3 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_COULOMB, .scale = 0 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_F, .scale = -6 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_F, .scale = -7 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_PH, .scale = -2 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_BAR, .scale = 0 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_PA, .scale = 2 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_CD, .scale = -2 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_CTS, .scale = -3 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_PERCENT, .scale = -3 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_PERMILL, .scale = -4 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_PPM, .scale = -6 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_PPB, .scale = -9 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_GPM3, .scale = -1 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_CPM3, .scale = -1 } },
+    { .dim = 3, .dat = { .val = { 56, 34, 12 }, .unit = UNIT_TIME, .scale = -1 } },
+    { .dim = 3, .dat = { .val = { 27, 2, 2020 }, .unit = UNIT_DATE, .scale = -1 } },
+};
+
+int main(void)
+{
+    puts("Visual phydat test application");
+
+    for (unsigned int i = 0; i < ARRAY_SIZE(_test_vector); i++) {
+        phydat_dump(&_test_vector[i].dat, _test_vector[i].dim);
+    }
+    return 0;
+}
diff --git a/tests/phydat_dump/tests/01-run.py b/tests/phydat_dump/tests/01-run.py
new file mode 100755
index 0000000000..b17dbe7b82
--- /dev/null
+++ b/tests/phydat_dump/tests/01-run.py
@@ -0,0 +1,67 @@
+#!/usr/bin/env python3
+
+# Copyright (C) 2020 Gunar Schorcht
+#
+# This file is subject to the terms and conditions of the GNU Lesser
+# General Public License v2.1. See the file LICENSE in the top level
+# directory for more details.
+
+import sys
+from testrunner import run
+
+
+def testfunc(child):
+    child.expect('Visual phydat test application\r\n')
+    child.expect('Data:\t          12.34 °C\r\n')
+    child.expect('Data:\t          12.34 °F\r\n')
+    child.expect('Data:\t          123.4 K\r\n')
+    child.expect('Data:\t          123.4 lx\r\n')
+    child.expect('Data:\t\[0\]        1234 m\r\n')
+    child.expect('\t\[1\]       13456 m\r\n')
+    child.expect('\t\[2\]      -14567 m\r\n')
+    child.expect('Data:\t\[0\]      1234e1 m\r\n')
+    child.expect('\t\[1\]     13456e1 m\r\n')
+    child.expect('\t\[2\]    -14567e1 m\r\n')
+    child.expect('Data:\t\[0\]        1234 km\r\n')
+    child.expect('\t\[1\]       13456 km\r\n')
+    child.expect('\t\[2\]      -14567 km\r\n')
+    child.expect('Data:\t\[0\]       12.34 m\r\n')
+    child.expect('\t\[1\]      134.56 m\r\n')
+    child.expect('\t\[2\]     -145.67 m\r\n')
+    child.expect('Data:\t\[0\]        1234 mm\r\n')
+    child.expect('\t\[1\]       13456 mm\r\n')
+    child.expect('\t\[2\]      -14567 mm\r\n')
+    child.expect('Data:\t       -0.12345 m\^2\r\n')
+    child.expect('Data:\t      -12345e-6 m\^3\r\n')
+    child.expect('Data:\t\[0\]        0.12 g\r\n')
+    child.expect('\t\[1\]        0.34 g\r\n')
+    child.expect('\t\[2\]       56.78 g\r\n')
+    child.expect('Data:\t\[0\]         123 mdps\r\n')
+    child.expect('\t\[1\]         345 mdps\r\n')
+    child.expect('\t\[2\]         678 mdps\r\n')
+    child.expect('Data:\t         1234.5 G\r\n')
+    child.expect('Data:\t          12345 kA\r\n')
+    child.expect('Data:\t          12345 MV\r\n')
+    child.expect('Data:\t        12345e7 W\r\n')
+    child.expect('Data:\t         1234.5 Gs\r\n')
+    child.expect('Data:\t         12.345 dBm\r\n')
+    child.expect('Data:\t          12345 C\r\n')
+    child.expect('Data:\t          12345 uF\r\n')
+    child.expect('Data:\t       12345e-7 F\r\n')
+    child.expect('Data:\t         123.45 pH\r\n')
+    child.expect('Data:\t          12345 Bar\r\n')
+    child.expect('Data:\t          12345 hPa\r\n')
+    child.expect('Data:\t         123.45 cd\r\n')
+    child.expect('Data:\t          12345 mcts\r\n')
+    child.expect('Data:\t         12.345 %\r\n')
+    child.expect('Data:\t         1.2345 permille\r\n')
+    child.expect('Data:\t          12345 uppm\r\n')
+    child.expect('Data:\t          12345 nppb\r\n')
+    child.expect('Data:\t         1234.5 g/m\^3\r\n')
+    child.expect('Data:\t         1234.5 #/m\^3\r\n')
+    child.expect('Data:\t12:34:56\r\n')
+    child.expect('Data:\t2020-02-27\r\n')
+
+
+if __name__ == "__main__":
+    sys.exit(run(testfunc, timeout=10))