Revision 0:230008e7b5c8, committed 2019-04-27

Comitter:

bwest32

Date:

Sat Apr 27 21:51:38 2019 +0000

Commit message:

First implementation of DSHOT150 on LPC-1768

Changed in this revision

diff -r 000000000000 -r 230008e7b5c8 DSHOT150.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DSHOT150.cpp	Sat Apr 27 21:51:38 2019 +0000
@@ -0,0 +1,87 @@
+#include "DSHOT150.h"
+#include "mbed.h"
+DSHOT150::DSHOT150(PinName pin) : _pin(pin)
+{
+    _pin = 0;
+    tel = 0;
+}
+void DSHOT150::write_zero()
+{
+    int i = 0;
+    while (i<19) {
+        _pin.write(1);
+        i++;
+    }
+    while (i<51) {
+        _pin.write(0);
+        i++;
+    }
+}
+void DSHOT150::write_one()
+{
+    int i = 0;
+    while (i<40) {
+        _pin.write(1);
+        i++;
+    }
+    while (i<51) {
+        _pin.write(0);
+        i++;
+    }
+}
+void DSHOT150::check_sum(unsigned int v)
+{
+    v = v<<1;
+    v = v|tel;
+    uint8_t cs;
+    for( int i = 0; i < 3; ++i){
+        cs ^= v;
+        v>>=4;
+    }
+    cs&=0xF;
+    packet[15] = cs&0x1;
+    packet[14] = cs&0x2;
+    packet[13] = cs&0x4;
+    packet[12] = cs&0x8;
+}
+void DSHOT150::get_tel(bool v)
+{
+    tel = v == true? 1 : 0;
+}
+void DSHOT150::send_packet()
+{
+    for(int j = 0; j < 1000; ++j) {
+        for(int i = 0; i < 16; ++i) {
+            if(packet[i])
+                write_one();
+            else
+                write_zero();
+        }
+        wait_us(500);
+    }
+}
+void DSHOT150::arm(){
+    throttle(0.25);
+    throttle(0);
+}
+void DSHOT150::throttle(float speed)
+{
+    unsigned int val;
+    speed = speed > 1 ? 1 : speed; //Bound checking and restricitng of the input
+    speed = speed < 0 ? 0 : speed; //Anything below 0 is converted to zero
+                                   //Anything above 1 is converted to one 
+                                   
+    val = (unsigned int)(speed * 2000); //Scale the throttle value. 0 - 48 are reserved for the motor
+    val +=48;                           //Throttle of zero starts at 48
+    
+    check_sum(val); //Calculate the checksum and insert it into the packet
+    
+    for(int i = 10; i >= 0; --i) {  //Insert the throttle bits into the packet
+        packet[i] = val&0x1;
+        val = val>>1;
+    }
+    
+    packet[11] = tel;   //Set the telemetry bit in the packet
+    
+    send_packet();
+}
\ No newline at end of file

diff -r 000000000000 -r 230008e7b5c8 DSHOT150.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DSHOT150.h	Sat Apr 27 21:51:38 2019 +0000
@@ -0,0 +1,69 @@
+/*
+    Copyright (c) 2019 Blake West, Kevin Tseng, Tyler Brown, Mason Totri
+ 
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+ 
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+ 
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+*/
+#ifndef MBED_DSHOT15_H
+#define MBED_DSHOT15_H
+#include "mbed.h"
+/** DSHOT150 converts a digital IO pin to act like a DSHOT pulse
+ * This is done through writing one's and zero's a specific amount 
+ * to acheive the correct pulse width in the given duty cycle.
+ *
+ *
+ * Example
+ * @code
+ * #include "mbed.h"
+ * #include "DSHOT150.h"
+ *
+ * DSHOT150 motor( p21 );
+ *
+ * int main() {
+ *
+ *      motor.arm();
+ *      motor.get_tel( true );
+ *      for( float i = 0; i < 1; i+=0.1){
+ *          motor.throttle( i );
+ *      }
+ *
+ *
+ *  }
+ *  @endcode
+ *
+ *  This example will step the motor from 0 to 100% in 10% intervals
+ *
+ */
+class DSHOT150
+{
+public:
+    DSHOT150(PinName pin); //Constructor that takes in 
+    void throttle(float speed); //Throttle value as a percentage [0,1]
+    void get_tel(bool v); //Telemetry request function. Set to true if wanting to receive telemetry from the ESC
+    void arm(); //Arming comand for the motor
+    
+private:
+    void send_packet(); //Sends the packet
+    void check_sum(unsigned int v); //Calculates the check sum, and inserts it into the packet
+    void write_zero(); 
+    void write_one();
+    bool packet[16]; //Packet of data that is being sent
+    DigitalOut _pin; //Pin that is being used.
+    unsigned int tel;
+};
+#endif
\ No newline at end of file