Arm Mbed OS support forum

Trouble interfacing with LPC1768 with custom pin definitions

I am trying to use mbed to flash firmware onto my SKR V1.3 to get around controlling it using g-code due to personal needs but my firmware does nothing when flahsed. I’ve added custom pin definitions to PinNames.h in the TARGET_LPC13XX folder and after compiling it successfully to a firmware.bin file in platformio, I plug it in back into my board and it does nothing. The SKR V1.3 already has a bootloader on it which reads from the sd card so I don’t know why my motors won’t spin when I turn the board on with the below .cpp file.

main.cpp:

#include "mbed.h"

DigitalOut xEN(P2_1); //Pin 74 of LPC
DigitalOut xSTP(P2_2); //Pin 73 of LPC
DigitalOut xDIR(P2_6); //Pin 67 of LPC

int main() {

    xDIR = 1; //Sets dir pin to high and direction to clockwise

   //Should keep spinning till I unplug the SKR V1.3
    while(1) {
        xSTP = 1;
        thread_sleep_for(0.002);
        xSTP = 0;
        thread_sleep_for(0.002);
    }
}

Modified PinNames.h file:

/* mbed Microcontroller Library
 * Copyright (c) 2006-2013 ARM Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef MBED_PINNAMES_H
#define MBED_PINNAMES_H

#include "cmsis.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef enum {
    PIN_INPUT,
    PIN_OUTPUT
} PinDirection;

#define PORT_SHIFT  5

typedef enum {
    // LPC1347 Pin Names
    P0_0 = 0,
    P0_1 = 1,
    P0_2 = 2,
    P0_3 = 3,
    P0_4 = 4,
    P0_5 = 5,
    P0_6 = 6,
    P0_7 = 7,
    P0_8 = 8,
    P0_9 = 9,
    P0_10 = 10,
    P0_11 = 11,
    P0_12 = 12,
    P0_13 = 13,
    P0_14 = 14,
    P0_15 = 15,
    P0_16 = 16,
    P0_17 = 17,
    P0_18 = 18,
    P0_19 = 19,
    P0_20 = 20,
    P0_21 = 21,
    P0_22 = 22,
    P0_23 = 23,
    //Extra pin definitons I put her personally
    P0_24 = 24,            // Pin 08 - LPC1768
    P0_25 = 25,           // Pin 07 - LPC1768
    P0_26 = 26,            // Pin 06 - LPC1768
    P0_27 = 27,            // Pin 25 - LPC1768
    P0_28 = 28,            // Pin 24 - LPC1768
    P0_29 = 29,            // Pin 29 - LPC1768
    P0_30 = 30,            // Pin 47 - LPC1768


    // Extra pins definitions I put there personally
    P1_0 = 32,              // Pin 95 - LPC1768
    P1_1 = 33,              // Pin 94 - LPC1768
    P1_4 = 36,              // Pin 93 - LPC1768
    P1_8 = 40,              // Pin 92 - LPC1768
    P1_9 = 41,              // Pin 91 - LPC1768
    P1_10 = 42,            // Pin 90 - LPC1768
    P1_13 = 45,
    P1_14 = 46,
    P1_15 = 47,
    P1_16 = 48,

    //Extra pins definitions I put there personally
    P1_17 = 49,            // Pin 86 - LPC1768
    P1_18 = 50,            // Pin 32 - LPC1768

    P1_19 = 51,
    P1_20 = 52,
    P1_21 = 53,
    P1_22 = 54,
    P1_23 = 55,
    P1_24 = 56,
    P1_25 = 57,
    P1_26 = 58,
    P1_27 = 59,
    P1_28 = 60,
    P1_29 = 61,
    //extra pin I put in personally
    P1_30 = 62,            // Pin 21 - LPC1768

    P1_31 = 63,

    //Extra pins I put in personally
    P2_0 = 64,            // Pin 75 - LPC1768
    P2_1 = 65,             // Pin 74 - LPC1768
    P2_2 = 66,             // Pin 73 - LPC1768
    P2_3 = 67,             // Pin 70 - LPC1768
    P2_4 = 68,             // Pin 69 - LPC1768
    P2_5 = 69,             // Pin 68 - LPC1768
    P2_6 = 70,             // Pin 67 - LPC1768
    P2_7 = 71,             // Pin 66 - LPC1768
    P2_8 = 72,             // Pin 65 - LPC1768
    P2_9 = 73,             // Pin 64 - LPC1768
    P2_10 = 74,             // Pin 53 - LPC1768
    P2_11 = 75,           // Pin 52 - LPC1768
    P2_12 = 76,           // Pin 51 - LPC1768
    P2_13 = 77,           // Pin 50 - LPC1768

    p1  = P0_0,
    p2  = P0_11,
    p3  = P0_12,
    p4  = P0_13,
    p5  = P0_14,
    p6  = P1_31,
    p8  = P0_16,
    p9  = P0_22,
    p10 = P0_23,
    p13 = P1_29,
    p14 = P1_21,
    p15 = P0_8,
    p16 = P0_9,
    p17 = P1_24,
    p18 = P0_4,
    p19 = P1_13,
    p20 = P1_14,
    p21 = P1_22,
    p22 = P0_17,
    p23 = P0_5,
    p24 = P0_21,
    p25 = P0_19,
    p26 = P0_18,
    p27 = P1_15,
    p28 = P1_16,
    p29 = P1_25,
    p30 = P1_19,
    p33 = P0_20,
    p34 = P0_2,
    p35 = P1_26,
    p36 = P1_27,
    p37 = P1_20,
    p38 = P1_23,
    p39 = P0_7,
    p40 = P1_28,

    UART_TX = P0_19,
    UART_RX = P0_18, 

    // Not connected
    NC = (int)0xFFFFFFFF,

    LED1 = p21,
    LED2 = p21,
    LED3 = p21,
    LED4 = p21,

    // Standard but not supported pins
    USBTX = NC,
    USBRX = NC,

} PinName;

typedef enum {
    CHANNEL0 = PIN_INT0_IRQn,
    CHANNEL1 = PIN_INT1_IRQn,
    CHANNEL2 = PIN_INT2_IRQn,
    CHANNEL3 = PIN_INT3_IRQn,
    CHANNEL4 = PIN_INT4_IRQn,
    CHANNEL5 = PIN_INT5_IRQn,
    CHANNEL6 = PIN_INT6_IRQn,
    CHANNEL7 = PIN_INT7_IRQn
} Channel;

typedef enum {
    PullUp = 2,
    PullDown = 1,
    PullNone = 0,
    Repeater = 3,
    OpenDrain = 4,
    PullDefault = PullDown
} PinMode;

#ifdef __cplusplus
}
#endif

#endif

SKR V1.3 schematic link: https://github.com/bigtreetech/BIGTREETECH-SKR-V1.3/blob/master/BTT%20SKR%20V1.3/hardware/SKR-V1.3-SCH.pdf

Hi,

Can you measure that your new output pins work? Just set 1 and 0 in second delay and measure with multimeter. You could also try something like this:
int main() {
while (true) {
xSTP = !xSTP;
wait(0.002);
}
}

Regards,
Pekka

Hello,

I tested pins voltages on the stepper drivers chips for STP and DIR when I set:

xDIR =1;

and xSTP = 1;

and xDIR = 0;

and xSTP = 0;

and no matter the configuration, xSTP relative to xGND is always 2V and xDIR relative to xGND is always 0V, regardless if I set the pins to high or low.