Add note about DWT cycle counter being requried for i2c

TheZoq2 · TheZoq2 · commit 7f33ced95fff · 2021-01-02T11:25:02.000+01:00
diff --git a/src/i2c.rs b/src/i2c.rs
@@ -98,6 +98,9 @@ pub struct I2c<I2C, PINS> {
 }
 
 /// embedded-hal compatible blocking I2C implementation
+///
+/// **NOTE**: Before using blocking I2C, you need to enable the DWT cycle counter using the
+/// [DWT::enable_cycle_counter] method.
 pub struct BlockingI2c<I2C, PINS> {
     nb: I2c<I2C, PINS>,
     start_timeout: u32,

Original file line number	Diff line number	Diff line change
`@@ -98,6 +98,9 @@ pub struct I2c<I2C, PINS> {`
`98`	`98`	`}`
`99`	`99`
`100`	`100`	`/// embedded-hal compatible blocking I2C implementation`
	`101`	`+///`
	`102`	`+/// NOTE: Before using blocking I2C, you need to enable the DWT cycle counter using the`
	`103`	`+/// [DWT::enable_cycle_counter] method.`
`101`	`104`	`pub struct BlockingI2c<I2C, PINS> {`
`102`	`105`	`nb: I2c<I2C, PINS>,`
`103`	`106`	`start_timeout: u32,`