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/*
* Copyright 2020 Birte Kristina Friesel
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "driver/am2320.h"
#if defined(CONFIG_meta_driver_hardware_i2c)
#include "driver/i2c.h"
#elif defined(CONFIG_driver_softi2c)
#include "driver/soft_i2c.h"
#endif
#include "arch.h"
void AM2320::read()
{
txbuf[0] = 0;
i2c.xmit(address, 1, txbuf, 0, rxbuf);
arch.delay_ms(1);
txbuf[0] = 3;
txbuf[1] = 0;
txbuf[2] = 4;
rxbuf[3] = rxbuf[4] = rxbuf[5] = rxbuf[6] = 0;
i2c.xmit(address, 3, txbuf, 0, rxbuf);
arch.delay_ms(3);
i2c.xmit(address, 0, txbuf, 8, rxbuf);
}
unsigned char AM2320::getStatus()
{
if (rxbuf[0] != 3) {
return 1;
}
if (rxbuf[1] != 4) {
return 2;
}
unsigned short checksum = 0xffff;
for (unsigned char i = 0; i < 6; i++) {
checksum ^= rxbuf[i] & 0x00ff;
for (unsigned char j = 0; j < 8; j++) {
if (checksum & 0x0001) {
checksum = (checksum >> 1) ^ 0xa001;
} else {
checksum >>= 1;
}
}
}
if ((rxbuf[6] != (checksum & 0x00ff)) || (rxbuf[7] != (checksum >> 8))) {
return 3;
}
return 0;
}
float AM2320::getTemp()
{
if (rxbuf[5] & 0x80) {
return (-256 * (rxbuf[4] & 0x7f) + rxbuf[5]) / 10.;
}
return (256 * rxbuf[4] + rxbuf[5]) / 10.;
}
float AM2320::getHumidity()
{
return (rxbuf[2] * 256 + rxbuf[3]) / 10.;
}
AM2320 am2320(0x5c);
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