New Micros, Inc

rob

08-11-00, 06:33 PM

Here's some code I used to control eight robot limbs with the PWM output (4) and then PWM mode of the timer outputs (4). The only missing definition is : +BITS DUP >R C@ OR R> C! ;( Actuator drivers for crabots Rob Chapman May 18, 1999 ) HEX \ There are 8 actuators controlling 8 joints on four limbs. They are \ referenced with respect to Front, Back, Left and Right, inner and \ outer. For example, FRI would be the Front Right inner joint. \ The four back joints are controlled by the four PWM outputs on \ the 68HC12. The four front joints are controlled by four timer \ outputs used with a fifth timer to create four PWM outputs. \ The PWM outputs drive a darlington transistor which grounds the \ actuator providing a path for current to flow through it. \ \ Mapping of the joints to HC12 pins: \ FLI - PT6 \ FRO - PT5 \ FRI - PT4 \ FLO - PT3 \ BLO - PP3 \ BLI - PP2 \ BRO - PP1 \ BRI - PP0\ ==== Registers ==== 41 CONSTANT PWPOL \ PWM outputs 42 CONSTANT PWEN \ PWN enables 50 CONSTANT PWDTY0 \ duty cycle for channel 0 51 CONSTANT PWDTY1 \ duty cycle for channel 1 52 CONSTANT PWDTY2 \ duty cycle for channel 2 53 CONSTANT PWDTY3 \ duty cycle for channel 3 56 CONSTANT PORTP \ port P outputs 82 CONSTANT OC7M \ output compare 7 mask register 83 CONSTANT OC7D \ output compare 7 data register 96 CONSTANT TC3 \ timer 3 register 98 CONSTANT TC4 \ timer 4 register 9A CONSTANT TC5 \ timer 5 register 9C CONSTANT TC6 \ timer 6 register 9E CONSTANT TC7 \ timer 7 register \ PWM outputs : BRI ( n -- ) PWDTY0 C! ; : BRO ( n -- ) PWDTY1 C! ; : BLI ( n -- ) PWDTY2 C! ; : BLO ( n -- ) PWDTY3 C! ;\ Timer PWM outputs : FRI ( n -- ) TC4 C! ; : FRO ( n -- ) TC5 C! ; : FLI ( n -- ) TC6 C! ; : FLO ( n -- ) TC3 C! ;: INIT-ACTUATORS ( -- ) \ initialize timers and counters \ PWM first 0 PORTP C! \ set outputs to zero just in case they are used F PWPOL C! \ set initial output as high F PWEN C! \ enable the PWM outputs \ timers next F8 TIOS +BITS \ PT3-PT7 are output capture FFFF TC7 ! \ set TC7 to just before zero 78 OC7M C! \ control PT3-6 with output capture 7 78 OC7D C! \ set to one when capture 7 matches 2A TCTL1 C! 80 TCTL2 C! \ set to zero when capture 3-6 matches 90 TSCR C! ; \ start the timer: LB DUP BLI BLO ; : RB DUP BRI BRO ; : LF DUP FLI FLO ; : RF DUP FRI FRO ; : BK DUP LB RB ; : FT DUP LF RF ; : LT DUP LF LB ; : RT DUP RF RB ; : ALL DUP LT RT ;: OFF 0 ALL ;