tests/periph/adc_multi: add test for reading two ADC lines to buffer

tests/periph/adc_multi/Makefile

@@ -0,0 +1,8 @@
+BOARD ?= same54-xpro
+include ../Makefile.periph_common
+
+FEATURES_REQUIRED = periph_adc_multi
+USEMODULE += ztimer
+USEMODULE += ztimer_msec
+
+include $(RIOTBASE)/Makefile.include

tests/periph/adc_multi/main.c

@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2024 ML!PA Consulting GmbH
+ *
+ * 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       Test application for taking multiple samples from two ADCs in parallel
+ *
+ * @author      Benjamin Valentin <[email protected]>
+ *
+ * @}
+ */
+
+#include <stdio.h>
+
+#include "macros/units.h"
+#include "periph/adc.h"
+#include "ztimer.h"
+
+#define RES             ADC_RES_10BIT
+#define DELAY_MS        100U
+#define NUM_SAMPLES     128U
+#define SAMPLE_FREQ     KHZ(100)
+
+int main(void)
+{
+    if (ADC_NUMOF < 2) {
+        printf("This test needs at leasst 2 ADC lines\n");
+        return -1;
+    }
+
+    /* initialize two ADC lines */
+    for (unsigned i = 0; i < 2; i++) {
+        if (adc_init(ADC_LINE(i)) < 0) {
+            printf("Initialization of ADC_LINE(%u) failed\n", i);
+            return 1;
+        } else {
+            printf("Successfully initialized ADC_LINE(%u)\n", i);
+        }
+    }
+
+    while (1) {
+        uint16_t samples[2][NUM_SAMPLES];
+
+        const adc_t lines[] = { ADC_LINE(0), ADC_LINE(1) };
+
+        adc_sample_multi(2, lines, NUM_SAMPLES, samples, RES, SAMPLE_FREQ);
+
+        for (unsigned i = 0; i < NUM_SAMPLES; ++i) {
+            printf("%u\t%u\n", samples[0][i], samples[1][i]);
+        }
+
+        ztimer_sleep(ZTIMER_MSEC, DELAY_MS);
+    }
+
+    return 0;
+}