From 101ab3f8fb746be69229b7fefc10ab085cf26d22 Mon Sep 17 00:00:00 2001
From: Paul Sajna <sajattack@gmail.com>
Date: Mon, 18 Feb 2019 02:40:06 -0800
Subject: [PATCH] uart rx

---
 src/serial.rs | 35 +++++++++++++++++++++++++++++++----
 1 file changed, 31 insertions(+), 4 deletions(-)

diff --git a/src/serial.rs b/src/serial.rs
index d1de010..ce287a6 100644
--- a/src/serial.rs
+++ b/src/serial.rs
@@ -1,7 +1,6 @@
 use embedded_hal::digital::{OutputPin, InputPin};
 use embedded_hal::blocking::delay::DelayUs;
 use embedded_hal::serial;
-use embedded_hal::serial::{Write, Read};
 use crate::time::Hertz;
 
 pub struct Serial<TX, RX, Delay> 
@@ -48,16 +47,16 @@ where
     type Error = ();
 
     fn write(&mut self, byte: u8) -> nb::Result<(), Self::Error> {
-        let mut out_byte = byte;
+        let mut data_out = byte;
         self.tx.set_low(); // start bit
         self.delay.delay_us(self.delay_time);
         for _bit in 0..8 {
-            if out_byte & 1 == 1 {
+            if data_out & 1 == 1 {
                 self.tx.set_high();
             } else {
                 self.tx.set_low();
             }
-            out_byte >>= 1;
+            data_out >>= 1;
             self.delay.delay_us(self.delay_time);
         }
         self.tx.set_high(); // stop bit
@@ -69,3 +68,31 @@ where
         Ok(())
     }
 }
+
+impl <TX, RX, Delay> serial::Read<u8> for Serial <TX, RX, Delay>
+where 
+    TX: OutputPin,
+    RX: InputPin,
+    Delay: DelayUs<u32> 
+{
+
+    type Error = ();
+
+    fn read(&mut self) -> nb::Result<u8, Self::Error> {
+        let mut data_in = 0;
+        // wait for start bit
+        while self.rx.is_high() {}
+        // catch the middle of the first bit
+        self.delay.delay_us((self.delay_time as f32 * 1.5) as u32); 
+        for _bit in 0..8 {
+            data_in <<= 1;
+            if self.rx.is_high() {
+               data_in |= 1
+            }
+            self.delay.delay_us(self.delay_time);
+        }
+        // wait for stop bit
+        self.delay.delay_us(self.delay_time);
+        Ok(data_in)
+    }
+}