Explorer pHat & C(++)

#1

Hey there!

Any one out there written a C or C++ driver for the explorer pHat? Or can anyone from the crew point me in the right direction to get something like this off the ground quicker?

Happy to re-post code after!

Cheers
Alex

#2

Got bored - here’s a quick implementation of a motion controller using the Explorer pHat in C++, the same logic can be applied to other pins on the board:

class MotionController
{
    enum PimoroniMotorPins
    {
        M1B = 19,
        M1F = 20,
        M2B = 21,
        M2F = 26
    };
    
    template<int PIN_F, int PIN_B>
    class Motor
    {
        enum { kForwardPin = PIN_F, kBackwardPin = PIN_B };
        
        bool m_initialized;
    
    public:
        Motor()
            : m_initialized(false)
        {}
    
        bool init()
        {
            int result = wiringPiSetupGpio();
            if (result != 0)
            {
                throw std::runtime_error("Failed to init wiring pi");
                return false;
            }
            
            pinMode(kForwardPin, OUTPUT);
            result = softPwmCreate(kForwardPin, 0, 100);
            if (result != 0)
            {
                throw std::runtime_error("Failed to create SW PWM pin");
                return false;
            }
        
            pinMode(kBackwardPin, OUTPUT);
            result = softPwmCreate(kBackwardPin, 0, 100);
            if (result != 0)
            {
                throw std::runtime_error("Failed to create SW PWM pin");
                return false;
            }
        
            m_initialized = true;
            
            return true;
        }
    
        void setSpeed(float speed)
        {
            if (!m_initialized) return;
        
            int fwdCycle  = (int)(saturate( speed) * 100 + 0.5f);
            int backCycle = (int)(saturate(-speed) * 100 + 0.5f);
        
            softPwmWrite(kForwardPin, fwdCycle);
            softPwmWrite(kBackwardPin, backCycle);
        }
    };
    
    Motor<M1F, M1B> m_motorLeft;
    Motor<M2F, M2B> m_motorRight;
    
public:
    enum MotorSide
    {
        kLeft = 1,
        kRight = 2,
        
        kNumMotors
    };

    bool init()
    {
        if (!m_motorLeft.init() || !m_motorRight.init())
        {
            return false;
        }
        
        return true;
    }

    void setSpeed(const MotorSide motor, float speed)
    {
        switch (motor)
        {
        case kRight:
            {
                m_motorRight.setSpeed(speed);
                break;
            }
        case kLeft:
            {
                m_motorLeft.setSpeed(speed);
                break;
            }
        }
    }
};
#3

Thanks for starting this. A year later it’s still getting hits.

I am compiling it on a Pi with GCC with a bunch of includes and one bodge as follows:
#include <wiringPi.h>
#include <softPwm.h>
#include
#include
#define saturate(x) x

I’m not able to get anywhere further though. could you show an example of using the class?