PIC16F684 to L239D Driver to Bipolar Stepper Motor. Programming question.

[TwistedE]

PIC16F684 to L293D Driver to Bipolar Stepper Motor. Programming question.

Hi,
I'm a bit confused in my project that uses a pic microcontoller to send information to a motor driver which in turn tells the motor exactly how far to move and supplies the appropriate required current.

My questions are:

1. Do I have to program the L293D motor driver or is it pre-programmed?
2. What kind of information do I have to send from the PIC to the driver and how is this to be done? Are there any examples of this?

I know about 90% of the required hardware connections and am using MPLAB and MikroC to program the PIC microcontroller. If the L239D driver requires programming, please refer me to a program and language that allows this.

Thank you.

 

[MikeMl]

You have to make it do what you want by programming the port pins. Find a data sheet, and read it. Here is a partial one.

 

[TwistedE]

Thanks for the reply.
I was actually meaning to refer to the L293D but accidentally made a typo in the thread title.

Anyways, I have some knowledge now and I'm trying to program my pic on mikroBasic PRO but I'm having some small issues in the code.

program Prog1

'int x;

main:

PORTA = 0
ANSEL = 0
TRISC = 0b110000
T1CON = 0b00010001

  for x = 1 to 50
   {
   
      PORTC = 0b001010;
      PORTC = 0b000110;
      PORTC = 0b000101;
      PORTC = 0b001001;
    
      for  (n = 0; n < 259; n++);   // 4ms Delay
    
   }
 end

Here are the errors:
0 1 mBPic.exe -DBG -pP16F684 -MSF -Y -DL -O11111114 -fo8 -N"C:\Users\***\Desktop\PIC16F684 Program\Prog1.mbppi" -SP"C:\Users\Public\Documents\Mikroelektronika\mikroBasic PRO for PIC\defs\" -SP"C:\Users\Public\Documents\Mikroelektronika\mikroBasic PRO for PIC\Uses\P16\" -SP"C:\Users\***\Desktop\PIC16F684 Program\" "__Lib_Math.mcl" "__Lib_MathDouble.mcl" "__Lib_System.mcl" "__Lib_Delays.mcl" "__Lib_CType.mcl" "__Lib_String.mcl" "__Lib_Conversions.mcl" "__Lib_Time.mcl" "__Lib_Trigon.mcl" "__Lib_Trigonometry.mcl" "__Lib_Button.mcl" "__Lib_Manchester.mcl" "__Lib_OneWire.mcl" "__Lib_PS2.mcl" "__Lib_Sound.mcl" "__Lib_SoftI2C.mcl" "__Lib_SoftSPI.mcl" "__Lib_SoftUART.mcl" "__Lib_ADC_A_B.mcl" "__Lib_EEPROM.mcl" "__Lib_PWM_c5.mcl" "__Lib_LcdConsts.mcl" "__Lib_Lcd.mcl" "Prog1.mbas"
0 155 Available RAM: 112 [bytes], Available ROM: 2048 [bytes]
0 133 Compilation Started C:\Users\***\Desktop\PIC16F684 Program\Prog1.mbas
1 1015 Hint: Compiling unit "C:\Users\***\Desktop\PIC16F684 Program\Prog1.mbas" Prog1.mbas
9 304 Syntax error: Expected "integral constant" but "0b110000" found Prog1.mbas
10 304 Syntax error: Expected "integral constant" but "0b00010001" found Prog1.mbas
12 301 "for"is not valid identifier Prog1.mbas
12 304 Syntax error: Expected "end" but "for" found Prog1.mbas
12 304 Syntax error: Expected "." but "x" found Prog1.mbas
0 102 Finished (with errors): 24 Feb 2011, 13:54:22 Prog1.mbppi



I know its a bit long but any help is appreciated. I'm basically trying to move my stepper motor 50 steps by sending Ports C0-3 with information from the table below:

Step wire 1 wire 2 wire 3 wire 4
1 High low high low
2 low high high low
3 low high low high
4 high low low high


The combination of the 4 steps moves the motor 1 step...hope all this makes sense.

 

[blueroomelectronics]

You need a delay between each step. You might want to use all eight bits when using the 0b prefix.

 

[TwistedE]

Thanks blueroomelectronics for the quick reply. I've modified the code to this:

program Prog1

'int x;

main:

PORTA = 0
ANSEL = 0
TRISC = 110000

for  (n = 0; n < 64750; n++);   // initial Delay of   1s


  for x = 1 to 50
   {
   
      PORTC = 001010;
       for  (n = 0; n < 259; n++);   // 4ms Delay
      PORTC = 000110;
       for  (n = 0; n < 259; n++);   // 4ms Delay
      PORTC = 000101;
       for  (n = 0; n < 259; n++);   // 4ms Delay
      PORTC = 001001;
       for  (n = 0; n < 259; n++);   // 4ms Delay

   } end

Sorry for the elementary questions but this is the first time I"m programming a pic microcontroller and it's not exactly a small project. Honestly, I'm not sure what the 0b is for, I just saw it on some examples on the internet.


Errors:
9 305 Argument is out of range "110000" to "byte" Prog1.mbas
9 327 Incompatible types ("complex type" to "simple type") Prog1.mbas
10 304 Syntax error: Expected "end" but "T1CON" found Prog1.mbas
10 304 Syntax error: Expected "." but "=" found Prog1.mbas
0 102 Finished (with errors): 24 Feb 2011, 14:36:55 Prog1.mbppi


Why are errors saying the argument is out of range. From what I understand, the PIC16F684 has RC0-5 so basically 6 bits right? I want to connect RC0-RC3 to the motor driver and send the step signals. During this whole time RC4 and 5 will be inputs with lows all the time. This is just a sample program to get the motors moving initially. Btw, I'm running it at 8mhz so each cycle is 125ns so I'm guessing a 4ms delay is more than sufficient.

Please hlep me with the programming errors.

 

[blueroomelectronics]

You've left out the 0b for some reason. You're also only showing 6 of 8 bits.

 

[TwistedE]

Somhow I figured out most of my errors and used Mikrobasic pro to program the PIC. I got it running with while loops but when I use subroutines it just twitches and returns back to the original position after moving 1 step I think.

Here is the code without subroutines for 100 steps

program Prog1

dim x as byte

main:

PORTA = 0
ANSEL = 0
TRISC = $30

x = 0

delay_ms(1000) ' delay of 1s

 while (x < 100)
 
      PORTC = $0A
       delay_ms(10)
      PORTC = $06
       delay_ms(10)
      PORTC = $05
       delay_ms(10)
      PORTC = $09
       delay_ms(10)
       
       x = x + 1
      
 wend

 end.

The above program runs fine for 100 steps but if I change it to a subroutine like below....I get a twitch.

while (x < 100)

Goto Forward
x = x + 1

wend

Forward:
     PORTC = $0A
       delay_ms(10)
      PORTC = $06
       delay_ms(10)
      PORTC = $05
       delay_ms(10)
      PORTC = $09
       delay_ms(10)