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hka5: Initial implementation

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This module implements support for the DFRobot Laser PM2.5 Sensor.  It
connects to a UART at 9600 baud.  This is the only baud rate
supported.  It optionally supports Reset and Set/Sleep gpios as well.

Signed-off-by: Jon Trulson <jtrulson@ics.com>
This commit is contained in:
Jon Trulson
2016-08-29 17:42:54 -06:00
committed by Noel Eck
parent 1b74f5335d
commit 21297e80d4
17 changed files with 1082 additions and 0 deletions
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257
src/hka5/hka5.c Normal file
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/*
* Author: Jon Trulson <jtrulson@ics.com>
* Copyright (c) 2016 Intel Corporation.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <string.h>
#include <assert.h>
#include "upm_utilities.h"
#include "hka5.h"
#define HKA5_BAUDRATE 9600 // Only baud supported
#define HKA5_PKT_SIZE 32
#define HKA5_PKT_START1 0x42
#define HKA5_PKT_START2 0x4d
static bool verify_cksum(uint8_t *pkt)
{
uint16_t pkt_cksum = (pkt[30] << 8) | pkt[31];
int i;
uint16_t cksum = 0;
for (i=0; i<(HKA5_PKT_SIZE - 2); i++)
cksum += pkt[i];
if (pkt_cksum == cksum)
return true; // all good
else
return false; // :(
}
hka5_context hka5_init(unsigned int uart, int set_pin, int reset_pin)
{
hka5_context dev =
(hka5_context)malloc(sizeof(struct _hka5_context));
if (!dev)
return NULL;
// zero out context
memset((void *)dev, 0, sizeof(struct _hka5_context));
dev->uart = NULL;
dev->gpio_reset = NULL;
dev->gpio_set = NULL;
// initialize the MRAA contexts
// uart, default should be 8N1
if (!(dev->uart = mraa_uart_init(uart)))
{
printf("%s: mraa_uart_init() failed.\n", __FUNCTION__);
hka5_close(dev);
return NULL;
}
if (mraa_uart_set_baudrate(dev->uart, HKA5_BAUDRATE))
{
printf("%s: mraa_uart_set_baudrate(%d) failed.\n", __FUNCTION__,
HKA5_BAUDRATE);
hka5_close(dev);
return NULL;
}
mraa_uart_set_flowcontrol(dev->uart, false, false);
// now the set_pin, if enabled
if (set_pin >= 0)
{
if (!(dev->gpio_set = mraa_gpio_init(set_pin)))
{
printf("%s: mraa_gpio_init(set) failed.\n", __FUNCTION__);
hka5_close(dev);
return NULL;
}
mraa_gpio_dir(dev->gpio_set, MRAA_GPIO_OUT);
// wake up
hka5_enable(dev, true);
}
// now the reset_pin, if enabled
if (set_pin >= 0)
{
if (!(dev->gpio_reset = mraa_gpio_init(reset_pin)))
{
printf("%s: mraa_gpio_init(reset) failed.\n", __FUNCTION__);
hka5_close(dev);
return NULL;
}
mraa_gpio_dir(dev->gpio_reset, MRAA_GPIO_OUT);
// reset
hka5_reset(dev);
}
return dev;
}
void hka5_close(hka5_context dev)
{
assert(dev != NULL);
// sleep
hka5_enable(dev, false);
if (dev->uart)
mraa_uart_stop(dev->uart);
if (dev->gpio_set)
mraa_gpio_close(dev->gpio_set);
if (dev->gpio_reset)
mraa_gpio_close(dev->gpio_reset);
free(dev);
}
upm_result_t hka5_enable(const hka5_context dev, bool enable)
{
assert(dev != NULL);
if (!dev->gpio_set)
return UPM_ERROR_NO_RESOURCES;
if (enable)
mraa_gpio_write(dev->gpio_set, 1);
else
mraa_gpio_write(dev->gpio_set, 0);
return UPM_SUCCESS;
}
upm_result_t hka5_reset(const hka5_context dev)
{
assert(dev != NULL);
if (!dev->gpio_reset)
return UPM_ERROR_NO_RESOURCES;
mraa_gpio_write(dev->gpio_set, 0);
upm_delay(1);
mraa_gpio_write(dev->gpio_set, 1);
upm_delay(1);
return UPM_SUCCESS;
}
upm_result_t hka5_update(const hka5_context dev)
{
assert(dev != NULL);
uint8_t pkt[HKA5_PKT_SIZE];
int idx = 0;
bool done = false;
char byte;
memset((void *)pkt, 0, HKA5_PKT_SIZE);
while (!done)
{
// wait up to 2 seconds for data and start
if (mraa_uart_data_available(dev->uart, 2000))
{
while ((mraa_uart_read(dev->uart, &byte, 1) == 1) &&
idx < HKA5_PKT_SIZE)
{
// first look for a byte starting with HKA5_PKT_START1
if (idx == 0 && byte != HKA5_PKT_START1)
continue;
// look for second byte, make sure it matches
// HKA5_PKT_START1. Start over if it's not found.
if (idx == 1 && byte != HKA5_PKT_START2)
{
// start over
idx = 0;
continue;
}
// else we found the byte, store it and start reading
// the rest
pkt[idx++] = (uint8_t)byte;
}
if (idx == HKA5_PKT_SIZE)
{
done = true;
}
else
{
// error
printf("%s: read failed.\n", __FUNCTION__);
return UPM_ERROR_OPERATION_FAILED;
}
}
else
{
printf("%s: read timed out.\n", __FUNCTION__);
return UPM_ERROR_TIMED_OUT;
}
}
// we have our data
if (verify_cksum(pkt))
{
dev->pm1 = (pkt[4] << 8) | pkt[5];
dev->pm2_5 = (pkt[6] << 8) | pkt[7];
dev->pm10 = (pkt[8] << 8) | pkt[9];
}
else
{
printf("%s: checksum failure.\n", __FUNCTION__);
// could fail here, but occasional cksum failures are not unusual...
}
return UPM_SUCCESS;
}
unsigned int hka5_get_pm1(const hka5_context dev)
{
assert(dev != NULL);
return (unsigned int)dev->pm1;
}
unsigned int hka5_get_pm2_5(const hka5_context dev)
{
assert(dev != NULL);
return (unsigned int)dev->pm2_5;
}
unsigned int hka5_get_pm10(const hka5_context dev)
{
assert(dev != NULL);
return (unsigned int)dev->pm10;
}