41 lines
1,020 B
C
41 lines
1,020 B
C
/**
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* Driver for 8-bit analog-to-digital conversion and
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* an 8-bit digital-to-analog conversion PCF8591
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*
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* Part of esp-open-rtos
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* Copyright (C) 2017 Pham Ngoc Thanh <pnt239@gmail.com>
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* 2017 Ruslan V. Uss <unclerus@gmail.com>
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* BSD Licensed as described in the file LICENSE
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*/
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#include "pcf8591.h"
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#include <stddef.h>
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#define BV(x) (1 << (x))
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#define CTRL_AD_CH_MASK 0x03
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#define CTRL_AD_IN_PRG 4
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#define CTRL_AD_IN_PRG_MASK (0x03 << CTRL_AD_IN_PRG)
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#define CTRL_DA_OUT_EN 6
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uint8_t pcf8591_read(i2c_dev_t *dev, pcf8591_input_conf_t conf, uint8_t channel)
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{
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uint8_t res = 0;
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uint8_t control_reg =
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((conf << CTRL_AD_IN_PRG) & CTRL_AD_IN_PRG_MASK) |
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(channel & CTRL_AD_CH_MASK) |
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BV(CTRL_DA_OUT_EN);
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i2c_slave_read(dev->bus, dev->addr, &control_reg, &res, 1);
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return res;
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}
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void pcf8591_write(i2c_dev_t *dev, uint8_t value)
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{
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uint8_t buf[2] = { BV(CTRL_DA_OUT_EN), value };
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i2c_slave_write(dev->bus, dev->addr, NULL, buf, 2);
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}
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