Merge pull request #21223 from crasbe/pr/adc_test

tests/adc: always test all resolutions

tests/periph/adc/README.md

@@ -6,8 +6,12 @@ continuously streamed to std-out.
 Background
 ==========
 This test application will initialize each configured ADC lines to sample with
-10-bit accuracy. Once configured the application will continuously convert each
-available channel and print the conversion results to std-out.
+6 to 16-bit accuracy. Once configured the application will continuously convert
+each available channel with each available resolution and print the conversion
+results to std-out.
+
+Not all MCUs support all resolutions and unsupported resolutions should be
+printed as -1.
 
 For verification of the output connect the ADC pins to known voltage levels
 and compare the output.

tests/periph/adc/main.c

@@ -23,16 +23,15 @@
 #include "ztimer.h"
 #include "periph/adc.h"
 
-#define RES             ADC_RES_10BIT
 #define DELAY_MS        100U
 
 int main(void)
 {
-    int sample = 0;
-
     puts("\nRIOT ADC peripheral driver test\n");
     puts("This test will sample all available ADC lines once every 100ms with\n"
-         "a 10-bit resolution and print the sampled results to STDIO\n\n");
+         "6 to 16-bit resolution and print the sampled results to STDOUT.\n"
+         "Not all MCUs support all resolutions, unsupported resolutions\n"
+         "are printed as -1.\n");
 
     /* initialize all available ADC lines */
     for (unsigned i = 0; i < ADC_NUMOF; i++) {
@@ -46,13 +45,17 @@ int main(void)
 
     while (1) {
         for (unsigned i = 0; i < ADC_NUMOF; i++) {
-            sample = adc_sample(ADC_LINE(i), RES);
-            if (sample < 0) {
-                printf("ADC_LINE(%u): selected resolution not applicable\n", i);
-            } else {
-                printf("ADC_LINE(%u): %i\n", i, sample);
-            }
+            int sample6  = adc_sample(ADC_LINE(i), ADC_RES_6BIT);
+            int sample8  = adc_sample(ADC_LINE(i), ADC_RES_8BIT);
+            int sample10 = adc_sample(ADC_LINE(i), ADC_RES_10BIT);
+            int sample12 = adc_sample(ADC_LINE(i), ADC_RES_12BIT);
+            int sample14 = adc_sample(ADC_LINE(i), ADC_RES_14BIT);
+            int sample16 = adc_sample(ADC_LINE(i), ADC_RES_16BIT);
+
+            printf("ADC_LINE(%u): %2i %3i %4i %4i %5i %5i\n", i, sample6, sample8, sample10,
+                   sample12, sample14, sample16);
         }
+        putchar('\n');
         ztimer_sleep(ZTIMER_MSEC, DELAY_MS);
     }