I was tinkering with BASCOM AVR and my 3PI robot… finally got it all working really well. Why BASCOM? Well… I’ve been programming BASIC since 1978 or so… yeah… I’m old. Anyway… it is much easer to set up than AVR Studio, and I’m still learning C so this way I can jump right in with programming.
If you haven’t seen my other thread… the current version of BASCOM may have issues with the USB programmer… so I loaded AVR Studio and use it to load the HEX files.
Anyway… this program will speed up and slow down the motors with a very simple routine so you can modify it as you wish.
'=======================================
'==== PWM Test Program
'==== September 25, 2008 / J Rutherford
'=======================================
$regfile = "m168def.dat" ' Set the chip as a Mega 168
$crystal = 20000000 ' Clock speed 20 MHZ
'=== Generic Port Setup ===
Config Portb = Output
Config Portc = Output
Config Portd = Output
Grn_led Alias Portd.7 ' Green User LED
Red_led Alias Portd.1 ' Red User LED
'=== LCD SETUP ===
Config Lcdpin = Pin , Db4 = Portb.1 , Db5 = Portb.4 , Db6 = Portb.5 , Db7 = Portd.7 , E = Portd.4 , Rs = Portd.2
Config Lcd = 16 * 2 ' Actually 8x2 but that is not recognized by BASCOM.
Rw Alias Portb.0 : Rw = 0 ' Set to Zero to write to the LCD
Cursor = Off
'=== PWM SETUP ===
Config Timer0 = Pwm , Prescale = 1 , Compare A Pwm = Clear Down , Compare B Pwm = Clear Down
Config Timer2 = Pwm , Prescale = 1 , Compare A Pwm = Clear Down , Compare B Pwm = Clear Down
'=======================================
' Program Start Here
'=======================================
Dim X As Word ' Set up a simple variable
Cls
Lcd "START"
Locate 2 , 1
For X = 1 To 5
Lcd "*"
Wait 1
Next X
Cls
Lcd "Speeding"
' Speed up to max
For X = 1 To 254
Gosub Robot_forward
Waitms 40
Next X
Cls
Lcd "Slowing"
' Slow down to zero
For X = 254 To 0 Step -1
Gosub Robot_forward
Waitms 40
Next X
' Be sure motors are stopped
Cls
Lcd "Stopped"
Locate 2 , 1
Lcd " -DONE- "
Gosub Robot_stop
'=======================================
Do : Loop ' Just waste time at the end
End 'end program
'=======================================
' Subroutines Here
'=======================================
Robot_forward:
Pwm0a = X : Pwm0b = 0 : Pwm2a = X : Pwm2b = 0
Return
Robot_stop:
Pwm0a = 0 : Pwm0b = 0 : Pwm2a = 0 : Pwm2b = 0
Return
Robot_reverse:
Pwm0a = 0 : Pwm0b = X : Pwm2a = 0 : Pwm2b = X
Return
Robot_right:
Pwm0a = 0 : Pwm0b = X : Pwm2a = X : Pwm2b = 0
Return
Robot_left:
Pwm0a = X : Pwm0b = 0 : Pwm2a = 0 : Pwm2b = X
ReturnI hope this helps you.
Jerry