Fixed audio playback test: added a missing conversion from 12 bit to 8 bit

tests/platform/gimmi_ridimmi.c

@@ -190,10 +190,18 @@ int main()
     gpio_setMode(BEEP_OUT, ALTERNATE);
     gpio_setAlternateFunction(BEEP_OUT, 2);
 
+    gpio_setPin(GREEN_LED);
+
     delayMs(3000);
 
     recordMic(sampleBuf);
 
+    /* Convert samples from 12 bit to 8 bit, as required by PWM audio */
+    for(size_t i = 0; i < numSamples; i++)
+    {
+        sampleBuf[i] >>= 4;
+    }
+
     /* End of recording, play sound */
     gpio_clearPin(GREEN_LED);
     gpio_setPin(RED_LED);