Abraham Howell
This class library has been created for use with the Apeiros Robot by Abe Howell's Robotics.
Apeiros is a low cost, flexible and entirely open source, educational mobile robot that has been designed for everyone by Abe Howell's Robotics, http://www.abotics.com. With an optional gripper mechanism Apeiros can manipulate objects and perform more advanced robotic tasks and experiments. Sensory expansion has been designed into this robot, so that you can add sensors as they are needed. I created Apeiros so that you can get hit the ground running in the wonderful world of robotics!
My Apeiros class library is released as open source under General Public License (GPL) Version 3, http://www.gnu.org/licenses/gpl-3.0.html, so please feel free to use and modify however you see fit.
Check out my Apeiros page for more information.
Below is an example main.cpp file that uses the Apeiros class library.
The Apeiros constructor passes a Serial transmit, tx, and receive, rx, PinName along with left and right motor PWM offsets. I am designing my wireless shield to use PA_9 for tx and PA_10 for rx. For now simply use the built-in USB serial connection by specifying SERIAL_TX & SERIAL_RX. No two gear motors will begin to rotate at the same PWM level, so I have allowed for the specification of a leftMotorPwmOffset and a rightMotorPwmOffset parameter. These values correspond to the PWM level that starts the respective motor rotating. You can determine these values by simply passing zero for the left and right PWM offsets. Then connect with Tera Term and issue the open-loop move command, MOxxx,yyy\r, where xxx is left motor speed and yyy is right motor speed (MO120,115\r). Simply vary the left and right motor speeds until you find the level at which each motor begins to rotate.These values will be the PWM motor offsets that need to be passed to the Apeiros constructor.
main.cpp
#include "mbed.h"
#include "Apeiros.h"
Apeiros apeiros(SERIAL_TX, SERIAL_RX,120,115);
int main() {
apeiros.Begin();
while(1) {
if (apeiros.IsSerialDataAvailable()) apeiros.ParseUartData();
// Add your custom code below//
}
}
Below is a simple obstacle avoidance program that uses sensory input from a front left and front right IR sensor. The front left sensor's OUT pin must be connected to PC_15 and the front right sensor's OUT pin to PC_13 on the Nucleo F401RE's Morpho header.
main.cpp
#include "mbed.h"
#include "Apeiros.h"
Apeiros apeiros(SERIAL_TX, SERIAL_RX,100,100);
int main() {
apeiros.Begin();
while(1) {
int sensorState = 2*apeiros.leftFrontIR.read();
sensorState += apeiros.rightFrontIR.read();
switch (sensorState) {
case 0:
apeiros.SetMotorSpeed(-65,-65);
apeiros.SetBuzzerTone(5);
break;
case 1:
apeiros.SetMotorSpeed(65,-65);
apeiros.SetBuzzerTone(50);
break;
case 2:
apeiros.SetMotorSpeed(-65,65);
apeiros.SetBuzzerTone(30);
break;
case 3:
apeiros.SetMotorSpeed(65,65);
apeiros.SetBuzzerTone(0);
break;
default:
apeiros.SetMotorSpeed(0,0);
break;
}
wait_ms(100);
}
Diff: Apeiros.h
- Revision:
- 3:c61c3feb0729
- Parent:
- 2:71ede4f26f71
--- a/Apeiros.h Tue Dec 16 17:54:27 2014 +0000
+++ b/Apeiros.h Tue Dec 23 23:29:00 2014 +0000
@@ -6,7 +6,7 @@
* #include "mbed.h"
* #include "Apeiros.h"
*
- * Apeiros apeiros(SERIAL_TX, SERIAL_RX, 120, 120);
+ * Apeiros apeiros(SERIAL_TX, SERIAL_RX, 100, 100);
*
* int main() {
* apeiros.Begin();
@@ -32,8 +32,10 @@
#define Ktps ((Cwh * TSCALE * INVTICK) / NCLKS)
#define MaxMotorSpeed 255
+// Hitec HS-81 accepts a 600 to 2400us pulse control signal. //
+// Do not use a value that is outside of the HS-81 specification! //
#define MIN_GRIPPER_PULSE 1000
-#define MAX_GRIPPER_PULSE 2300
+#define MAX_GRIPPER_PULSE 2200
#define MAX_BUZZER_PWM 100
@@ -49,10 +51,17 @@
/** Create Apeiros instance
*
- * @param tx specified as PinName of UART Tx pin. Use SERIAL_TX as default.
- * @param rx specified as PinName of UART Rx pin. Use SERIAL_RX as deafult.
- * @param leftMotorPwmOffset specified as integer value from 0-150. Use 120 as default.
- * @param rightMotorPwmOffset specified as integer value from 0-150. Use 120 as default.
+ * @param tx specified as PinName of UART Tx pin. Use SERIAL_TX as default. Use PA_9 for wireless shield.
+ * @param rx specified as PinName of UART Rx pin. Use SERIAL_RX as deafult. Use PA_10 for wireless shield.
+ * @param leftMotorPwmOffset specified as integer value from 0-150. Use 100 as default.
+ * @param rightMotorPwmOffset specified as integer value from 0-150. Use 100 as default.
+ *
+ * The PwmOffsets are used to eliminate the deadband for both the left & right motor, so
+ * that each motor begins to rotate when motor speeds are specified as aperiros.SetMotorSpeed(1,1).
+ *
+ * Pass a zero for each PwmOffset parameter and then use SetMotorSpeed function to find the leftMotorPwmOffset & rightMotorPwmOffset values.
+ *
+ * You have found the PwmOffset value when the respective motor goes from not rotating to starting rotation.
*/
Apeiros(PinName tx, PinName rx, int leftMotorPwmOffset, int rightMotorPwmOffset);
@@ -80,15 +89,26 @@
*/
void SetBuzzerTone(int buzzerTone);
- /** Set left and roght motor speeds.
+ /** Set left and right motor speeds.
+ *
+ * @param leftMotorSpeed specified as an integer value(int) from 0 to (255-leftMotorPwmOffset). Use a preceeding negative sign to reverse motor rotation.
+ * @param rightMotorSpeed specified as an integer value(int) from 0 to (255-rightMotorPwmOffset). Use a preceeding negative sign to reverse motor rotation.
+ *
+ * For example, if leftMotorPwmOffset = 95 then valid left motor speed range is 0 to 165. Use a preceeding negative sign to reverse motor rotation.
*
- * @param leftMotorSpeed specified as an integer value(int) from 0-150, rightMotorSpeed specified as an integer value(int) from 0-150.
+ * Drive robot forward with apeiros.SetMotorSpeed(65,65).
+ *
+ * Drive robot in reverse with apeiros.SetMotorSpeed(-65,-65).
+ *
+ * Spin robot clockwise with apeiros.SetMotorSpeed(65,-65).
+ *
+ * Spin robot counterclockwise with apeiros.SetMotorSpeed(-65,65).
*/
void SetMotorSpeed(int leftMotorSpeed, int rightMotorSpeed);
/** Set servo gripper position.
*
- * @param pulseWidth_us specified as an integer value(int) from MIN_GRIPPER_PULSE(1000) to MAX_GRIPPER_PULSE(2300).
+ * @param pulseWidth_us specified as an integer value(int) from MIN_GRIPPER_PULSE(1000) to MAX_GRIPPER_PULSE(2200).
*/
void SetGripperPosition(int pulseWidth_us);
@@ -111,15 +131,54 @@
*/
void ResetWheelEncoders(void);
+ /** DigitalIn object for Left Front IR Sensor.
+ *
+ */
DigitalIn leftFrontIR;
+
+ /** DigitalIn object for Center Front IR Sensor.
+ *
+ */
DigitalIn centerFrontIR;
+
+ /** DigitalIn object for Right Front IR Sensor.
+ *
+ */
DigitalIn rightFrontIR;
+ /** DigitalIn object for Left Rear IR Sensor.
+ *
+ */
+ DigitalIn leftRearIR;
+
+ /** DigitalIn object for Right Rear IR Sensor.
+ *
+ */
+ DigitalIn rightRearIR;
+
+ /** ad_0 AnalogIn object. Used to convert a varying voltage to a digital value.
+ *
+ */
AnalogIn ad_0;
+ /** ad_1 AnalogIn object. Used to convert a varying voltage to a digital value.
+ *
+ */
AnalogIn ad_1;
+ /** ad_2 AnalogIn object. Used to convert a varying voltage to a digital value.
+ *
+ */
AnalogIn ad_2;
+ /** ad_3 AnalogIn object. Used to convert a varying voltage to a digital value.
+ *
+ */
AnalogIn ad_3;
+ /** ad_4 AnalogIn object. Used to convert a varying voltage to a digital value.
+ *
+ */
AnalogIn ad_4;
+ /** ad_5 AnalogIn object. Used to convert a varying voltage to a digital value.
+ *
+ */
AnalogIn ad_5;