Three Phase BLDC in iOS

This example demonstrates the initialization and rpm control of a three phase brushless DC motor in iOS.

[source code]

// Legal/License Information:
//
// All information contained herein is, and remains the property of Vena 
// Engineering Corporation. This source code contains proprietary 
// information of Vena Engineering Corporation. This source code is 
// intended solely for use by parties operating and/or maintaining 
// equipment manufactured by Vena Engineering. Any use of this information 
// or content outside of this purpose is strictly prohibited. Such 
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// of Vena Engineering Corporation. The intellectual and technical concepts 
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// protected by trade secret or copyright law. Dissemination of this 
// information or reproduction of this material is strictly forbidden 
// unless prior written permission is obtained from Vena Engineering 
// Corporation. 
// 
// The software source is provided "as is", without warranty of any kind, 
// express or implied. In no event shall Vena Engineering Corporation be 
// liable for any claim, damages or other liability, in connection with the 
// provided software. 

#import "ViewController.h"
#import "pilib.h"

@interface ViewController ()

@end

const uint32_t MTR_TABLE_SIZE = 10;

@implementation ViewController {
    uint32_t handle;
    uint32_t encoder_cnts;
    uint32_t elec_cycle_div;
    uint32_t elec_cycle_per_sec;
    uint32_t phases;
    uint32_t poles;
    mtr_segment_t mtr_table[MTR_TABLE_SIZE];
}

- (void)viewDidLoad {
    [super viewDidLoad];

    handle = pidev_init("192.168.1.200", NULL, 0);
    
    [self configMotor];

    [NSTimer scheduledTimerWithTimeInterval:0.1
                                target:self
                                selector:@selector(processTimer:)
                                userInfo:nil
                                repeats:YES];
}

- (void)configMotor {
    phases = 3;
    poles = 4;
    encoder_cnts = 512*4;
    elec_cycle_div = 0.05 * DEFAULT_CLK_PIMOTION;
    elec_cycle_per_sec = DEFAULT_CLK_PIMOTION / elec_cycle_div;
    
    //configure the PiMotion to a motor type 3-PHASE
    mtr_set_mtr_type(handle, MTR_TYPE_3PHASE);
    mtr_set_poles(handle, poles);
    mtr_set_enc_counts_per_rot(handle, encoder_cnts);
    mtr_set_enc_polarity(handle, 0);
    mtr_set_use_aux_enc_for_servo(handle, 0);
    mtr_set_output_polarity(handle, 0);
    
    //set the pid and trajectory generator update rate
    mtr_set_elec_cycle_div(handle, elec_cycle_div);
    
    //set the pid gains (proportional, integral, derivitive)
    mtr_set_kp(handle, 4.0);
    mtr_set_ki(handle, 0.5);
    mtr_set_kd(handle, 8.0);
    mtr_set_ilim(handle, 30000.0);
    
    //motor limits and position error
    mtr_set_max_pid_output(handle, 30000);
    mtr_set_max_pos_error(handle, 0); // SERVOMODE_VELOCITY no pos_error
    
    //initial phase angle configuration parameters
    mtr_set_reset_current(handle, 18000);
    mtr_set_reset_wait_time_ms(handle, 2000);
    
    [self.rpmLabel setText:@"configMotor"];
    
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)resetButtonTouch:(id)sender {

    //reset the motor
    uint32_t reset_state = 999;
    
    [self setStatus:@"Resetting motor..."];
    mtr_write_phase_mem_default(handle, phases, poles, encoder_cnts);
    mtr_reset(handle);
    
    while (reset_state != 0) {
        [NSThread sleepForTimeInterval:0.1];
        mtr_get_reset_state(handle, &reset_state);
    }
    [self setStatus:@"Finished resetting."];
}

- (IBAction)rpmSliderValChanged:(UISlider *)sender {
    
    uint32_t rc = 0;
    int64_t actual_vel = 0;
    uint32_t num_segments = MTR_TABLE_SIZE;
    double cps = [self rpmToCps:sender.value];
    velocity_entry_t profile = {0.0, cps,[self rpmToCps:1000.0]};
    
    [self setStatus:[NSString stringWithFormat:@"cps = %.3f, rpm = %.3f", cps, sender.value]];

    if (rc == 0) rc = mtr_get_actual_vel(handle, &actual_vel);
    if (rc == 0) rc = mtr_create_velocity_profile(handle, (double)(actual_vel * elec_cycle_per_sec), 1, &profile, SERVOMODE_VELOCITY, elec_cycle_div, &num_segments, mtr_table);
    if (rc == 0) rc = mtr_write_table(handle, 0, num_segments, mtr_table);
    if (rc == 0) rc = mtr_start(handle, 0, TRIG_SRC_NONE);
    
    if (rc != 0) {
        [self.rpmLabel setText:[NSString stringWithFormat:@"%s", err_get_string_from_code(rc)]];
    }
}

- (void)setStatus:(NSString*) msg{
    [self.myLabel setText:msg];
}

- (void)processTimer:(NSTimer*)theTimer {
    
    int64_t actual_vel;
    double rpm;

    mtr_get_actual_vel(handle, &actual_vel);
    rpm = [self cpecToRpm:actual_vel];
    [self.rpmLabel setText:[NSString stringWithFormat:@"%.0f", rpm]];
}

- (double)cpecToRpm:(int64_t)cpec {
    
    return (cpec * elec_cycle_per_sec * 60.0) / encoder_cnts;
}

- (double)rpmToCps:(double)rpm {
    return (rpm * encoder_cnts) / 60.0;
}


@end