Correctly scale analog reading per issue #4794

PaintYourDragon · web-flow · commit 5ef1f2dd5a9c · 2022-05-24T08:45:14.000-07:00
diff --git a/ports/nrf/common-hal/analogio/AnalogIn.c b/ports/nrf/common-hal/analogio/AnalogIn.c
@@ -125,8 +125,8 @@ uint16_t common_hal_analogio_analogin_get_value(analogio_analogin_obj_t *self) {
         value = 0;
     }
 
-    // Map value to from 14 to 16 bits
-    return value << 2;
+    // Stretch 14-bit ADC reading to 16-bit range
+    return (value << 2) | (value >> 12);
 }
 
 float common_hal_analogio_analogin_get_reference_voltage(analogio_analogin_obj_t *self) {

Original file line number	Diff line number	Diff line change
`@@ -125,8 +125,8 @@ uint16_t common_hal_analogio_analogin_get_value(analogio_analogin_obj_t *self) {`
`125`	`125`	`value = 0;`
`126`	`126`	`}`
`127`	`127`
`128`		`- // Map value to from 14 to 16 bits`
`129`		`- return value << 2;`
	`128`	`+ // Stretch 14-bit ADC reading to 16-bit range`
	`129`	`+ return (value << 2) \| (value >> 12);`
`130`	`130`	`}`
`131`	`131`
`132`	`132`	`float common_hal_analogio_analogin_get_reference_voltage(analogio_analogin_obj_t *self) {`