nrf: fix adc read near zero

ysoldak · deadprogram · commit b7fcf6ad6840 · 2025-01-23T13:03:25.000+08:00
diff --git a/src/machine/machine_nrf52xxx.go b/src/machine/machine_nrf52xxx.go
@@ -183,7 +183,12 @@ func (a *ADC) Get() uint16 {
 		resolutionAdjustment = 4 // 12bit
 	}
 
-	return rawValue.Get() << resolutionAdjustment
+	value := int16(rawValue.Get())
+	if value < 0 {
+		value = 0
+	}
+
+	return uint16(value << resolutionAdjustment)
 }
 
 // SPI on the NRF.

Original file line number	Diff line number	Diff line change
`@@ -183,7 +183,12 @@ func (a *ADC) Get() uint16 {`
`183`	`183`	`resolutionAdjustment = 4 // 12bit`
`184`	`184`	`}`
`185`	`185`
`186`		`- return rawValue.Get() << resolutionAdjustment`
	`186`	`+ value := int16(rawValue.Get())`
	`187`	`+ if value < 0 {`
	`188`	`+ value = 0`
	`189`	`+ }`
	`190`	`+`
	`191`	`+ return uint16(value << resolutionAdjustment)`
`187`	`192`	`}`
`188`	`193`
`189`	`194`	`// SPI on the NRF.`