add digital read

examples/nightrider.rs

@@ -2,14 +2,14 @@ use std::{thread::sleep, time::Duration};
 
 use b15f::b15f::B15F;
 
-fn main() {
-	let mut drv = B15F::new().unwrap();
+fn main() -> Result<(), String> {
+	let mut drv = B15F::new()?;
 
 	let mut position = 0;
 	let mut direction = 1;
 
 	loop {
-		drv.digital_write::<0>(1 << position);
+		drv.digital_write::<0>(1 << position)?;
 
 		position += direction;
 		if position >= 7 || position <= 0 {

examples/read.rs

@@ -0,0 +1,8 @@
+use b15f::b15f::B15F;
+
+fn main() -> Result<(), String> {
+	let mut drv = B15F::new()?;
+
+	println!("{}", drv.digital_read::<0>().unwrap());
+	Ok(())
+}