Motor Driver for large dc motor issues can you help? please

Other Hardware Motors, Mechanics, Power and CNC
1

Hello

Im mid creating a cable cam with rc unit. I have engineered a great bit of hardware and found some good arduino code and had my new unit running up the line but I have a problem or two and any help will be greatly recieved. Once the unit is up and running Ill happily share the combined knowledge for all.
Im using a 12v/24v dc motor ( taken from a kids electric scooter) not sure what amps whatts it uses but ran from 2x12v batteries.
I have an ardunino uno withr an nrf24l01-rf unit for RX and L928n driver board for the motor.
I have an arduino nano with an nrf24l01-rf unit for TX with thumbstick joystick for controle.

Problems
1 when I run the motor direct with a 3s lipo (12v) battery the motor goes down the 11mm line perfect but when its run via the arduino setup it has very little power and will only go down a 5mm line.
So i thought to increase the volt in (as the L928n takes upto 36v) I tried 18v in but a pop n spark and the l928n is dead any ideas? How would I get more volts in?

2 When it was working the code I used is for 2 motors and 2 tumbsticks to control. I only use 1 motor and 1 thumbstick, I can get the motor going one way when i push forward (with varying speed which is perfect) but when I pull the stick back the motor doesn't work in reverse. This is needed to get the camera rig back along the line. I have attached the rx n tx code I use as txt file if any one could look and see and help or even make it better Ill be eternally great full. My coding aint the best.

So long of the short how do I put more v through the L928n driver board without blowing it and how do I get my motor to go backwards thanks.

Thanks Simon

RX TX CODE arduino cable cam.txt (15.9 KB)

2

Please post your two sketches correctly, using code tags. This is all explained carefully in
the sticky threads about how to post here.

You'll have to explain clearly what you are doing, I can't make much sense of it.

One thing I can say is that an L298 is completely hopeless for driving a big motor like that,
it cannot handle the stall current even remotely, you were overdriving it completely.

Characterize your motor beter (measure the winding resistance, post a photo of any nameplate it
may have, or at least a photo of it with rough dimensions). I suspect it wants something more like
10A continuous 40A peak driver. Its probably in the 100 to 200W range.

As for the mechanics I suspect you have no idea if the motor / gearing is over or under powered,
so you might want to share some info on that too.

3

RX code

/********************************************************************************
*RC RX code for 2 motors n 2 thumbsticks cable cam setup																	*
*																				*
*	CS		- Arduino digital pin 8,  nRF24L01 pin 3 (CE)						*
*	CSN 	- Arduino digital pin 9,  nRF24L01 pin 4 (CSN)						*
*	MOSI 	- Arduino digital pin 11, nRF24L01 pin 6 (MOSI) 					*
*	MISO 	- Arduino digital pin 12, nRF24L01 pin 7 (MISO)						*
*	CLK 	- Arduino digital pin 13, nRF24L01 pin 5 (SCK) 						*
*																				*
/*******************************************************************************/

#include <SPI.h>
#include "nRF24L01.h"

#define TX_ADR_WIDTH	5
#define TX_PLOAD_WIDTH	9

#define CE				8
#define CSN				9
#define IRQ				10
#define MOSI                            11
#define MISO                            12

int EN_A  = 5;      // to 1,2EN of L293D
int EN_B  = 6;     // to 3,4EN of L293D
int IN_A1 = 2;      // to 1A of L293D
int IN_A2 = 3;      // to 2A of L293D
int IN_B1 = 4;      // to 3A of L293D
int IN_B2 = 7;      // to 4A of L293D

int speed = 100;
boolean dir = 1;  // 1 (true) indicates forward, 0 indicates reverse

// Define a static TX address
unsigned char TX_ADDRESS[TX_ADR_WIDTH]  = { 0x34, 0x43, 0x10, 0x10, 0x01 };

unsigned char rx_buf[TX_PLOAD_WIDTH] = { 0 };	// initialize value
unsigned char tx_buf[TX_PLOAD_WIDTH] = { 0 };

int x_val = 0;
int y_val = 0;
int left_speed = 0;
int right_speed = 0;

unsigned long time = 0;
const uint64_t pipeIn =  0xE8E8F0F0E1LL;
//**************************************************
void setup() 
{
	Serial.begin( 9600 );
	init_motors();
	pinMode( CE,  OUTPUT );
	pinMode( CSN, OUTPUT );
	pinMode( IRQ, INPUT );
    pinMode( MOSI, OUTPUT );
    pinMode( MISO, INPUT );
	SPI.begin();
	delay( 50 );
	init_io();		// Initialize IO port	
	unsigned char status = SPI_Read( STATUS );
	Serial.println( "*** Get Status ***" );
	Serial.print( "status = " );    
	Serial.println( status, HEX );			// read the modes status register, 
											// the default value should be 'E'
	Serial.println( "******************" );
	RX_Mode();			// set RX mode
}

//**************************************************
void loop() 
{
	int k = 0;
	int i = 0, j = 0, fail = 0, found = 0;
	int lim = TX_PLOAD_WIDTH;
	unsigned char value[lim];

	
	for( i = 0; i < lim; i++ ) {
		rx_buf[i] = 0;
	}
	
	unsigned char status = SPI_Read( STATUS );			// read register STATUS's value
	if( status & RX_DR )								// if receive data ready (TX_DS) interrupt
	{
		SPI_Read_Buf( R_RX_PAYLOAD, rx_buf, TX_PLOAD_WIDTH );	// read playload to rx_buf
		SPI_RW_Reg( FLUSH_RX, 0 );								// clear RX_FIFO

		for ( i = 0; i < lim ; i++ )  value[i] = 0;
		
		i = 0;      j = 0;
		while( (rx_buf[i++] != '/') && !fail ) {
			if ( i > lim ) { fail = 1; break; }
			if ( rx_buf[i] == '/' )  found = 1;
		}
		
		if ( found == 1 && !fail ) {
			while( (rx_buf[i] != '*') && !fail ) {
				if ( i > lim ) { fail = 1; break; }
				value[j++] = rx_buf[i++]; 
				if ( rx_buf[i] == '*' )  found = 2;
			}
        
			if ( found == 2 && !fail ) {
				x_val = value[0];
				y_val = value[1];
				
				time = millis();
				
				if ( y_val < 130 || y_val > 140 ) {
					if ( y_val < 130 ) {
						y_val = map( y_val, 130, 0, 0, 255 );
						dir = 0;
					}
					else if ( y_val > 140 ) {
						y_val = map( y_val, 140, 255, 0, 255 );
						dir = 1;
					}
					
					left_speed = y_val;
					right_speed = y_val;
					
					if ( x_val < 120 || x_val > 130 ) {
						if ( x_val < 120 ) {	// turn left
							x_val = map( x_val, 120, 0, 0, y_val );
							left_speed -= x_val;
						}
						else if ( x_val > 130 ) {	// turn right
							x_val = map( x_val, 130, 255, 0, y_val );
							right_speed -= x_val;
						}
					}
				} else {
					left_speed = 0;
					right_speed = 0;
				}
				
				set_left_motor(left_speed, dir);
                set_right_motor(right_speed, dir);                                
				
                Serial.print("speed: ");  
				Serial.print(left_speed);
				Serial.print(", ");  
				Serial.print(right_speed);
				Serial.print(", direction:");
				Serial.println(dir);
				  
				x_val = 0; 
				y_val = 0; 
				left_speed = right_speed = 0;
			}
		}
 
		if ( fail ) {
            Serial.println("FAIL");
            stop_motors();
        }
		
/*
		for( i=0; i < strlen((char *)rx_buf); i++ )
		{
			//Serial.print( rx_buf[i], HEX );	// print rx_buf as HEX
			Serial.write( rx_buf[i] );			// print rx_buf as Ascii Characters
		}
		//Serial.println( " " );
*/
	}
	
	SPI_RW_Reg( W_REGISTER+STATUS, status );	// clear RX_DR or TX_DS or MAX_RT interrupt flag
	
	if ( millis() - time > 2000 ) {
		// stop
        stop_motors();
		//Serial.println("timeout");
	}

//	delay( 1000 );
}

//**************************************************
void init_io (void )
{
	digitalWrite( IRQ, 0 );
	digitalWrite( CE, 0 );		// chip enable
	digitalWrite( CSN, 1 );		// SPI disable	
}

//**************************************************
unsigned char SPI_Read( unsigned char reg )
{
	unsigned char reg_val;

	digitalWrite( CSN, 0 );		// CSN low, initialize SPI communication...
	SPI_RW( reg );				// Select register to read from..
	reg_val = SPI_RW( 0 );		// ..then read register value
	digitalWrite( CSN, 1 );		// CSN high, terminate SPI communication

	return( reg_val );			// return register value
}

//**************************************************
unsigned char SPI_RW( unsigned char Byte )
{
	return SPI.transfer( Byte );
}

//**************************************************
unsigned char SPI_Read_Buf( unsigned char reg, unsigned char *pBuf, unsigned char bytes )
{
	unsigned char status, i;

	digitalWrite( CSN, 0 );		// Set CSN low, init SPI tranaction
	status = SPI_RW( reg );		// Select register to write to and read status unsigned char

	for( i = 0; i < bytes; i++ )
	{
		pBuf[i] = SPI_RW( 0 );		// Perform SPI_RW to read unsigned char from nRF24L01
	}

	digitalWrite( CSN, 1 );		// Set CSN high again

	return( status );				// return nRF24L01 status unsigned char
}

//**************************************************
unsigned char SPI_Write_Buf( unsigned char reg, unsigned char *pBuf, unsigned char bytes )
{
	unsigned char status, i;

	digitalWrite( CSN, 0 );		// Set CSN low, init SPI tranaction
	status = SPI_RW( reg );		// Select register to write to and read status unsigned char
	for( i = 0; i < bytes; i++ )	// then write all unsigned char in buffer(*pBuf)
	{
		SPI_RW( *pBuf++ );
	}
	digitalWrite( CSN, 1 );			// Set CSN high again
	return( status );				// return nRF24L01 status unsigned char
}

//**************************************************
unsigned char SPI_RW_Reg( unsigned char reg, unsigned char value )
{
	unsigned char status;

	digitalWrite( CSN, 0 );			// CSN low, init SPI transaction
	status = SPI_RW( reg );			// select register
	SPI_RW( value );				// ..and write value to it..
	digitalWrite( CSN, 1 );			// CSN high again

	return( status );				// return nRF24L01 status unsigned char
}

//**************************************************
void RX_Mode( void )
{
	digitalWrite( CE, 0 );

	SPI_Write_Buf( W_REGISTER + RX_ADDR_P0, TX_ADDRESS, TX_ADR_WIDTH );	// use same address as transmitting device

	SPI_RW_Reg( W_REGISTER + EN_AA, 0x01 );				// Enable auto acknowledgement data pipe 0
	SPI_RW_Reg( W_REGISTER + EN_RXADDR, 0x01 );			// Enable data pipe 0
	SPI_RW_Reg( W_REGISTER + RF_CH, 40 );				// Select RF channel 40
	SPI_RW_Reg( W_REGISTER + RX_PW_P0, TX_PLOAD_WIDTH );// Select same RX payload width as TX Payload width  
	SPI_RW_Reg( W_REGISTER + RF_SETUP, 0x07 );			// TX_PWR:0dBm, Datarate:2Mbps, LNA:HCURR
	SPI_RW_Reg( W_REGISTER + CONFIG, 0x0f );			// POWER UP, enable 2-byte CRC & PRX as RX/TX control
														// RX_DR, TX_DS & MAX_RT interrupts enabled
	digitalWrite( CE, 1 );
}

void init_motors() {
  // set output modes
  pinMode(IN_A1, OUTPUT);
  pinMode(IN_A2, OUTPUT);
  pinMode(IN_B1, OUTPUT);
  pinMode(IN_B2, OUTPUT);
  pinMode(EN_A, OUTPUT);
  pinMode(EN_B, OUTPUT);
  
  // initialize ports to safely turn off the motors
  stop_motors();
}

void stop_motors(){
  set_left_motor( 0, dir);
  set_right_motor( 0, dir);
}

void set_left_motor(int speed, boolean dir) {
  speed = constrain(speed, 0, 255);
  analogWrite(EN_A, speed);     // PWM on enable lines
  digitalWrite(IN_A1, dir);
  digitalWrite(IN_A2, ! dir);
}

void set_right_motor(int speed, boolean dir) {
  speed = constrain(speed, 0, 255);  
  analogWrite(EN_B, speed);
  digitalWrite(IN_B1, dir);
  digitalWrite(IN_B2, ! dir);
}
4

TX code

#include <SPI.h>
#include "nRF24L01.h"

#define TX_ADR_WIDTH		5
#define TX_PLOAD_WIDTH		9

#define CE			 		8
#define CSN					9
#define IRQ					10
#define MOSI                            11
#define MISO                            12
int ledPin = 2;		//LED 

int speed_x;
int speed_y;

int potPin_x = 0; //potentiometer to control the speed of motor 1
int potPin_y = 1; //potentiometer to control the speed of motor 2

// Define a static TX address
unsigned char TX_ADDRESS[TX_ADR_WIDTH]	= { 0x34, 0x43, 0x10, 0x10, 0x01 }; 

unsigned char rx_buf[TX_PLOAD_WIDTH] = { 0 }; 	// initialize value
unsigned char tx_buf[TX_PLOAD_WIDTH] = "UUU/XY*$";

const uint64_t pipeIn =  0xE8E8F0F0E1LL;
//**************************************************
void setup() 
{
	Serial.begin( 9600 );
	pinMode( ledPin, OUTPUT );
	pinMode( CE, OUTPUT );
	pinMode( CSN, OUTPUT );
	pinMode( IRQ, INPUT );
	pinMode(potPin_x, INPUT); 
	pinMode(potPin_y, INPUT); 
  
	SPI.begin();
	delay( 50 );
	init_io();		// Initialize IO port
	unsigned char status = SPI_Read( STATUS );
	Serial.println( "*** Get Status ***" );
	Serial.print( "status = " );
	Serial.println( status, HEX );					// read the modes status register, 
													//the default value should be 'E'
	Serial.println( "******************" );
	TX_Mode();										// set TX mode

/*	
	String helloWorld = "hello world\n";
	for ( int i = 0; i < helloWorld.length(); i++ )
		tx_buf[i] = (unsigned char)helloWorld[i];
*/
	blink(ledPin, 10, 200);  //indicate start/restart 
}

//**************************************************
void loop() 
{
	int k = 0;

	speed_x = analogRead(potPin_x)/4;
	speed_y = analogRead(potPin_y)/4;
	//if ( speed_x < 50 ) speed_x = 50;
	//if ( speed_y < 50 ) speed_y = 50;
	tx_buf[4] = speed_x; 
	tx_buf[5] = speed_y;
	
	
	Serial.print("Speed: "); 
	Serial.print(speed_x);
	Serial.print(", "); 
	Serial.println(speed_y);  
/*	Serial.print("  "); 
	Serial.write(tx_buf, sizeof(tx_buf));
	Serial.println(" |");
	*/
	
	unsigned char status = SPI_Read( STATUS );	// read register STATUS's value

	// Data Sent TX FIFO interrupt, packet transmitted on TX, ACK received
	if( status & TX_DS )		
	{
		SPI_RW_Reg( FLUSH_TX, 0 );
		
		// write playload to TX_FIFO
		SPI_Write_Buf( W_TX_PAYLOAD, tx_buf, TX_PLOAD_WIDTH );
	}

	//Maximum number of TX retransmits occurred
	// if receive data ready (MAX_RT) interrupt, this is retransmit than SETUP_RETR													
	if( status & MAX_RT )		
	{
		SPI_RW_Reg( FLUSH_TX, 0 );
		SPI_Write_Buf( W_TX_PAYLOAD, tx_buf, TX_PLOAD_WIDTH );	// disable standy-mode
	}

	// clear RX_DR or TX_DS or MAX_RT interrupt flag
	SPI_RW_Reg( W_REGISTER + STATUS, status );	
	delay( 600 );
}

//**************************************************
void blink(int whatPin, int howManyTimes, int milliSecs) {
  for ( int i = 0; i < howManyTimes; i++) {
    digitalWrite(whatPin, LOW);
    delay(milliSecs/2);
    digitalWrite(whatPin, HIGH);
    delay(milliSecs/2);
  }
}

//**************************************************
void init_io(void)
{
	digitalWrite( IRQ, 0 );
	digitalWrite( CE, 0 );		// chip enable
	digitalWrite( CSN, 1 );		// SPI disable	
}

//**************************************************
unsigned char SPI_Read( unsigned char reg )
{
	unsigned char reg_val;

	digitalWrite( CSN, 0 );				// CSN low, initialize SPI communication...
	SPI_RW( reg );						// Select register to read from..
	reg_val = SPI_RW( 0 );				// ..then read register value
	digitalWrite( CSN, 1 );				// CSN high, terminate SPI communication

	return( reg_val );					// return register value
}

//**************************************************
unsigned char SPI_RW( unsigned char Byte )
{
	return SPI.transfer( Byte );
}

//**************************************************
unsigned char SPI_Read_Buf( unsigned char reg, unsigned char *pBuf, unsigned char bytes )
{
	unsigned char status, i;

	digitalWrite( CSN, 0 );			// Set CSN low, init SPI tranaction
	status = SPI_RW( reg );			// Select register to write to and read status unsigned char

	for( i = 0; i < bytes; i++ )
	{
		pBuf[i] = SPI_RW( 0 );		// Perform SPI_RW to read unsigned char from nRF24L01
	}

	digitalWrite( CSN, 1 );			// Set CSN high again

	return( status );				// return nRF24L01 status unsigned char
}

//**************************************************
unsigned char SPI_Write_Buf( unsigned char reg, unsigned char *pBuf, unsigned char bytes )
{
	unsigned char status, i;

	digitalWrite( CSN, 0 );			// Set CSN low, init SPI tranaction
	status = SPI_RW( reg );			// Select register to write to and read status unsigned char
	for( i = 0; i < bytes; i++ )	// then write all unsigned char in buffer(*pBuf)
	{
		SPI_RW( *pBuf++ );
	}
	digitalWrite( CSN, 1 );			// Set CSN high again
	return( status );				// return nRF24L01 status unsigned char
}

//**************************************************
unsigned char SPI_RW_Reg( unsigned char reg, unsigned char value )
{
	unsigned char status;

	digitalWrite( CSN, 0 );			// CSN low, init SPI transaction
	status = SPI_RW( reg );			// select register
	SPI_RW( value );				// ..and write value to it..
	digitalWrite( CSN, 1 );			// CSN high again

	return( status );				// return nRF24L01 status unsigned char
}

//**************************************************
void TX_Mode( void )
{
	digitalWrite( CE, 0 );

	SPI_Write_Buf( W_REGISTER + TX_ADDR, TX_ADDRESS, TX_ADR_WIDTH );	// Writes TX_Address to nRF24L01
	SPI_Write_Buf( W_REGISTER + RX_ADDR_P0, TX_ADDRESS, TX_ADR_WIDTH );	// RX_Addr0 same as TX_Adr for Auto.Ack
	
	SPI_RW_Reg( W_REGISTER + EN_AA, 0x01 );			// Enable auto acknowledgement data pipe 0
	SPI_RW_Reg( W_REGISTER + EN_RXADDR, 0x01 );		// Enable data pipe 0
	SPI_RW_Reg( W_REGISTER + SETUP_RETR, 0x1a );	// auto retransmit delay = 500us, retransmit count = 10
	SPI_RW_Reg( W_REGISTER + RF_CH, 40 );			// Select RF channel 40
	SPI_RW_Reg( W_REGISTER + RF_SETUP, 0x07 );		// TX_PWR:0dBm, Datarate:2Mbps, LNA:HCURR
	SPI_RW_Reg( W_REGISTER + CONFIG, 0x0e );		// POWER UP, enable 2-byte CRC & PTX as RX/TX control
													// RX_DR, TX_DS & MAX_RT interrupts enabled
	SPI_Write_Buf( W_TX_PAYLOAD, tx_buf, TX_PLOAD_WIDTH );

	digitalWrite( CE, 1 );
}
5

Hi
thanks iv'e put code up correct hopefully but i have not got much data on motor i've attached a pic of it and the l298n motor board.
Sorry if i not explain to well it always sounds ok in ya head.#
I wanted to know how to get more power to the L298n board without blowing it as I think if i get more power to board it will provide more torque to the motor as I need it ti go down a 11mm line / rope.
I also wanted to know why the motor wont go backwards I think its a problem in the rx code?
Thanks

IMG_20160606_131417.jpg
IMG_20160606_131417.jpg2560×1920 1.16 MB

6

I wanted to know how to get more power to the L298n board without blowing it

You can't, you are grossly exceeding its maximum current rating with a traction motor like that.