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GitHub Repository: Ardupilot/ardupilot
 Path: blob/master/Tools/Linux_HAL_Essentials/pru/rcinpru/rcinpru0.c
Views: 1800
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/*

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 * testpru

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 *

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 */

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#define PRU0

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#include <stdio.h>

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#include <stdlib.h>

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#include <stdarg.h>

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#include <stdio.h>

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#include <strings.h>

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#include "linux_types.h"

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#include "pru_defs.h"

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#include "prucomm.h"

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void add_to_ring_buffer(uint8_t v, uint16_t deltat)

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{

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    RBUFF->buffer[RBUFF->ring_tail].pin_value = v;

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    RBUFF->buffer[RBUFF->ring_tail].delta_t = deltat;

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    RBUFF->ring_tail = (RBUFF->ring_tail + 1) % NUM_RING_ENTRIES;

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}

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static inline u32 read_PIEP_COUNT(void)

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{

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    return PIEP_COUNT;

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}

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uint32_t read_pin(void){

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    return ((__R31&(1<<15)) != 0);

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}

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void main()

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{

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     uint32_t last_time_us = 0;

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     uint8_t last_pin_value = 0;

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     /*PRU Initialisation*/

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     PRUCFG_SYSCFG &= ~SYSCFG_STANDBY_INIT;

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     PRUCFG_SYSCFG = (PRUCFG_SYSCFG &

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             ~(SYSCFG_IDLE_MODE_M | SYSCFG_STANDBY_MODE_M)) |

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             SYSCFG_IDLE_MODE_NO | SYSCFG_STANDBY_MODE_NO;

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     /* our PRU wins arbitration */

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     PRUCFG_SPP |=  SPP_PRU1_PAD_HP_EN;

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    /* configure timer */

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    PIEP_GLOBAL_CFG = GLOBAL_CFG_DEFAULT_INC(1) |

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              GLOBAL_CFG_CMP_INC(1);

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    PIEP_CMP_STATUS = CMD_STATUS_CMP_HIT(1); /* clear the interrupt */

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        PIEP_CMP_CMP1   = 0x0;

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    PIEP_CMP_CFG |= CMP_CFG_CMP_EN(1);

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        PIEP_GLOBAL_CFG |= GLOBAL_CFG_CNT_ENABLE;

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     RBUFF->ring_tail = 20;

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     while (1) {

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        uint32_t v;

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        while ((v=read_pin()) == last_pin_value) {

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          // noop

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        }

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        uint32_t now = read_PIEP_COUNT()/200;

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        uint32_t delta_time_us = now - last_time_us;

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        last_time_us = now;

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        add_to_ring_buffer(last_pin_value, delta_time_us);

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        last_pin_value = v;

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     }

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}

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