Revision 1:0fadd6080445, committed 2020-02-03

Comitter:

jdonnal

Date:

Mon Feb 03 16:14:43 2020 +0000

Parent:

0:422eb3991ee3

Commit message:

Initial Commit

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Ir.cpp	Mon Feb 03 16:14:43 2020 +0000
@@ -0,0 +1,53 @@
+#include "Ir.h"
+ 
+ 
+IrIn::IrIn(PinName input): ir_(input){
+    ir_.rise(this, &IrIn::rising_edge_);
+    ir_.fall(this, &IrIn::falling_edge_);
+    ir_.disable_irq();
+    rx_bits_ = 0;
+    msg_ = 0x0;
+    rx_in_progress_ = 0;
+    rx_complete_ = 0;
+    t_.start();
+}
+
+int IrIn::read(){
+    ir_.enable_irq();
+    while(!rx_complete_)
+        wait(0.1);
+    int rx_msg = msg_;
+    msg_ = 0x0;
+    rx_complete_ = 0;
+    rx_bits_ = 0;
+    return rx_msg;
+}
+
+void IrIn::rising_edge_(){
+    char rx_bit = 0x0;
+    int dt = t_.read_us();
+    
+    //make sure we align to a start condition
+    if(!rx_in_progress_){
+        if(dt>2000 && dt < 2500){
+            rx_in_progress_ = 1;
+        }
+        return;
+    }
+    if(dt>700)
+        rx_bit = 0x1;
+    else
+        rx_bit = 0x0;
+    rx_bits_++;
+    msg_ = (msg_ << 1) | rx_bit;
+    if(rx_bits_ == 12){
+        rx_in_progress_ = 0;
+        rx_complete_ = 1;
+        ir_.disable_irq();
+    }
+    
+}
+
+void IrIn::falling_edge_(){
+    t_.reset();
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Ir.h	Mon Feb 03 16:14:43 2020 +0000
@@ -0,0 +1,44 @@
+
+/* Parallax High Speed Continuous Servo
+   John Donnal 2018
+*/
+
+#ifndef _IR_H
+#define _IR_H
+
+/**
+ * Includes
+ */
+#include "mbed.h"
+
+/**
+ * 38KHz IR Receiver (for Sony RM-EZ4 Remote) 
+ */
+class IrIn {
+
+public:
+
+    /**
+     * Constructor.
+     *
+     * @param output mbed pin for input channel.
+     */
+    IrIn(PinName input);
+
+    /**
+     * Decode IR data, blocks until data is received
+     */
+    int read();
+private:
+
+    void falling_edge_();
+    void rising_edge_();
+    InterruptIn ir_;
+    Timer t_;
+    int rx_in_progress_;
+    int rx_complete_;
+    int rx_bits_;
+    int msg_;
+};
+
+#endif /* CONTINUOUS_SERVO_H */