/* * assign21.S * * Updated on: Sep 16, 2012 * Author: patb * * Emulate a vending machine * */ .syntax unified #include "stm32f10x_asm.h" #define PBIN GPIOB_BASE+IDR #define PAIN GPIOA_BASE+IDR #define PAOUT GPIOA_BASE+ODR #define PBOUT GPIOB_BASE+ODR #define PCOUT GPIOC_BASE+ODR .global _start, state, selection, payment_count, money, total_money, vends .type _start, %function .text .word 0x20002000 // ideally, these should be in the vector table .word _start _start: main: bl initHardware bl initVariables main_loop: ldr r4,=state mov r5,#0 strb r5,[r4] // state = 0 bl idle // idle() mov r5,#1 strb r5,[r4] // state = 1 bl select // select() mov r5,#2 strb r5,[r4] // state = 2 bl purchase // purchase() mov r5,#3 strb r5,[r4] //state = 3 bl vend // vend() ldr r3,=selection mov r0,#0 strb r0,[r3] // after each vend, reset the selection and payment and money ldr r3,=payment_count strb r0,[r3] ldr r3,=money str r0,[r3] b main_loop // and repeat /* void initHardware(void) */ initHardware: // power up the zones of the chip ldr r0, =0x40021018 //RCC ldr r1, =0x00044a3d str r1,[r0] // turn on the normally not-connected pins ldr r0,=0x02008000 ldr r1,=0x40010004 str r0,[r1] // set the data direction registers ldr r1,=0x40010800 // DDRA_LO // nothing required ldr r1,=0x40010804 // DDRA_HI ldr r0,=0x44441444 str r0,[r1] // turn beeper pin into an output ldr r1,=0x40010C00 // DDRB_HI // nothring required ldr r1,=0x40010C04 // DDRB_HI ldr r0,=0x44444411 str r0,[r1] // enable the motor ldr r1,=0x40011000 // DDRC_HI mov r0,#0x11111111 str r0,[r1] ldr r1,=0x40011004 // DDRC_HI str r0,[r1] bx lr /* void initVariables(void) */ initVariables: // set up the state variables, all to zero mov r0,#0 ldr r1,=state strb r0,[r1] ldr r1,=selection strb r0, [r1] ldr r1,=payment_count str r0,[r1] ldr r1,=money str r0,[r1] ldr r1,=total_money str r0,[r1] ldr r1,=vends str r0,[r1] bx lr /* void idle(void) */ idle: push {r4,lr} // we'll use r4 to keep track of time main_idle_loop: mov r4, #0 // keep track of flashing lights // r4=0...99, lights on // r4=100...199 lights off ldr r1,=money str r4,[r1] // money = 0 inner_idle_loop: // watch the keyboard, and flash the lights ldr r1, =PBIN ldr r0, [r1] tst r0, #4 // check PBIN-2, ButtonA bne si_done ldr r1, =PAIN ldr r0, [r1] tst r0, #2 // check PAIN-1, main keybd bne si_done state_next: mov r0, #10 // delayMsec(10) bl delayMsec add r4, r4, #1 // increment the light counter cmp r4, #99 blo si_on cmp r4, #199 bhi main_idle_loop // if we get here, the lights should go off mov r0, #0 ldr r1,=PCOUT str r0, [r1] b inner_idle_loop si_on: movw r0,#0xFF00 // all the high bits of PortC on ldr r1,=PCOUT str r0,[r1] b inner_idle_loop si_done: pop {r4, pc} /* void select(void) */ select: // first we wait for the button to be released ldr r1, =PBIN ldr r0,[r1] tst r0,#4 bne select // check the other key as well ldr r1, =PAIN ldr r0,[r1] tst r0,#2 bne select // if we get here, the main keyboard is pressed and released ldr r1,=selection ldrb r0,[r1] // get the last selection lsl r0, r0, #1 ands r0, r0, #0x1F // only keep the bottom 5 bits bne ss_selection_ok // check to see if we've got 0 left mov r0,#1 // if so, start at bottom again ss_selection_ok: strb r0,[r1] // selection = (selection << 1) & 0xFF // put the selection on the LEDs ldr r2,=0x4001100C // PCOUT lsl r3, r0, #8 strh r3, [r2] // light up the LED's ss_again: // waiting for the keyboard to be pressed ldr r1, =0x40010808 // PAIN ldr r0,[r1] tst r0,#2 // PAIN-1 main keyboard bne select // also check for ButtonA press ldr r1, =0x40010C08 // PBIN ldr r0,[r1] tst r0,#4 // ButtonA beq ss_again // Button A is pressed, time to go back and change states bx lr // and return /* void purchase(void) */ purchase: push {r4,r5,r6,r7,lr} sp_main_loop: // put the money number on the 7 segment display ldr r2,=payment_count ldrb r6,[r2] // r3=payment_count ldr r4,=sevenSegLookup ldrb r5,[r4,r6] // look up the pattern for the 7 segment display ldr r7,=0x4001100C // PCOUT strh r5,[r7] // and light up the lights // now we count the wheel rotations sp_down: ldr r1,=PAIN ldr r0,[r1] tst r0,#1 // bottom bit is the rotary sensor beq sp_down // make a click sound and spin the motor ldr r2,=PAOUT ldrh r3,[r2] eor r3,r3,#0x0800 // change bit 11 strh r3,[r2] ldr r2,=PBOUT ldrh r3,[r2] orr r3,r3,#0x0100 // spin the motor strh r3,[r2] mov r0,#40 bl delayMsec ldr r2,=PBOUT ldrh r3,[r2] and r3,r3,#0xffffFCFF // stop spinning the motor strh r3,[r2] ldr r2,=payment_count ldrb r3,[r2] add r3,#1 // payment_count = payment_count + 1 strb r3,[r2] ldr r2,=money ldr r3,[r2] add r3, r3, #10 str r3,[r2] // money = money + 10 // if we've reached 90, then change to next state cmp r3,#90 beq sp_done // and wait for the wheel signal to go low again sp_up: ldr r1,=PAIN ldr r0,[r1] tst r0,#1 // bottom bit is the rotary sensor bne sp_up b sp_main_loop sp_done: pop {r4,r5,r6,r7,pc} // and return from subroutine seven_segment_data: .byte 0x3f,0x06,0x5B, 0x4F, 0x66, 0x6d, 0x7d, 0x07, 0x7F, 0x6F /* void vend(void) */ vend: push {r4,lr} // r4 will count up to 3 for the 3 flashes mov r0,#3 ldr r1,=state strb r0,[r1] // state = 3 ldr r1,=vends ldr r0,[r1] add r0,r0,#1 str r0,[r1] // vends = vends + 1 ldr r1,=total_money ldr r0,[r1] ldr r2,=money ldr r3,[r2] add r0,r0,r3 str r0,[r1] // total_money = total_money + money // now we just need to flash the lights // for (i=0; i<3; i++) mov r4,#3 sv_again: ldr r2,=selection ldrb r0,[r2] lsl r0, r0, #8 ldr r1,=0x4001100C // PCOUT strh r0,[r1] movw r0,#1000 bl delayMsec ldr r1,=0x4001100C mov r0,#0 strb r0,[r1] // lights off movw r0, #1000 bl delayMsec subs r4, r4, #1 bne sv_again pop {r4,pc} // return from subroutine /* void delayMsec(int n) * delays for n msec * n is passed in r0 * returns void * destroys r0, r1 */ delayMsec: ldr r1,=2667 // do this loop enough times to make a msec s1: subs r1, r1, #1 bne s1 // this loop is 3 cycles = .375usec subs r0, r0, #1 // are we done? bne delayMsec bx lr // this is the table that changes a small number into the pattern for the 7 segment display sevenSegLookup: .byte 0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07, 0x7f, 0x6f, 0x77 .data state: .byte 0 selection: .byte 0 payment_count: .byte 0 .byte 0 money: .word 0 total_money: .word 0 vends: .word 0