mirror of
https://github.com/RobTillaart/Arduino.git
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479 lines
8.9 KiB
C++
479 lines
8.9 KiB
C++
//
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// FILE: MCP23S08.cpp
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// AUTHOR: Rob Tillaart
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// VERSION: 0.1.2
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// PURPOSE: Arduino library for SPI MCP23S08 8 channel port expander
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// DATE: 2022-01-10
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// URL: https://github.com/RobTillaart/MCP23S08
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#include "Arduino.h"
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#include "MCP23S08.h"
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// Registers // description datasheet
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#define MCP23S08_DDR_A 0x00 // Data Direction Register A P..
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#define MCP23S08_POL_A 0x01 // Input Polarity A P..
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#define MCP23S08_GPINTEN_A 0x02 // NOT USED interrupt enable P..
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#define MCP23S08_DEFVAL_A 0x03 // NOT USED interrupt def P..
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#define MCP23S08_INTCON_A 0x04 // NOT USED interrupt control P..
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#define MCP23S08_IOCR 0x05 // IO control register P..
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#define MCP23S08_PUR_A 0x06 // Pull Up Resistors A P..
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#define MCP23S08_INTF_A 0x07 // NOT USED interrupt flag P..
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#define MCP23S08_INTCAP_A 0x08 // NOT USED interrupt capture P..
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#define MCP23S08_GPIO_A 0x09 // General Purpose IO A P..
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#define MCP23S08_OLAT_A 0x0A // NOT USED output latch P..
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// low level read / write masks
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#define MCP23S08_WRITE_REG 0x40
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#define MCP23S08_READ_REG 0x41
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/*
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MCP23S08::MCP23S08()
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{
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}
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*/
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MCP23S08::MCP23S08(uint8_t select, uint8_t dataIn, uint8_t dataOut, uint8_t clock, uint8_t address)
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{
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_address = address;
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_select = select;
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_dataIn = dataIn;
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_dataOut = dataOut;
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_clock = clock;
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_error = MCP23S08_OK;
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_hwSPI = false;
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}
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MCP23S08::MCP23S08(uint8_t select, uint8_t address)
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{
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_address = address;
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_select = select;
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_error = MCP23S08_OK;
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_hwSPI = true;
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}
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bool MCP23S08::begin()
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{
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::pinMode(_select, OUTPUT);
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::digitalWrite(_select, HIGH);
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_spi_settings = SPISettings(_SPIspeed, MSBFIRST, SPI_MODE0);// 8 MHz - datasheet page 8
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if (_hwSPI)
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{
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// TODO - ESP32 specific support - see MCP_ADC.
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mySPI = &SPI;
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mySPI->end();
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mySPI->begin();
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}
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else
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{
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::pinMode(_dataIn, INPUT);
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::pinMode(_dataOut, OUTPUT);
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::pinMode(_clock, OUTPUT);
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::digitalWrite(_dataOut, LOW);
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::digitalWrite(_clock, LOW);
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}
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// check connected
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if (! isConnected()) return false;
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// disable address increment (datasheet)
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if (! writeReg(MCP23S08_IOCR, 0b00100000)) return false; // TODO MAGIC NR
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// Force INPUT_PULLUP
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if (! writeReg(MCP23S08_PUR_A, 0xFF)) return false;
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return true;
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}
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bool MCP23S08::isConnected()
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{
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_error = MCP23S08_OK;
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return true;
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}
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// single pin interface
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// pin = 0..7
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// mode = INPUT, OUTPUT, INPUT_PULLUP (= same as INPUT)
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bool MCP23S08::pinMode(uint8_t pin, uint8_t mode)
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{
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if (pin > 7)
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{
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_error = MCP23S08_PIN_ERROR;
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return false;
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}
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if ((mode != INPUT) && (mode != INPUT_PULLUP) && (mode != OUTPUT))
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{
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_error = MCP23S08_VALUE_ERROR;
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return false;
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}
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uint8_t dataDirectionRegister = MCP23S08_DDR_A;
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uint8_t val = readReg(dataDirectionRegister);
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if (_error != MCP23S08_OK)
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{
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return false;
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}
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uint8_t mask = 1 << pin;
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// only work with valid
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if ((mode == INPUT) || (mode == INPUT_PULLUP))
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{
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val |= mask;
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}
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else if (mode == OUTPUT)
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{
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val &= ~mask;
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}
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// other values won't change val ....
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writeReg(dataDirectionRegister, val);
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if (_error != MCP23S08_OK)
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{
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return false;
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}
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return true;
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}
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// pin = 0..7
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// value = LOW, HIGH
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bool MCP23S08::digitalWrite(uint8_t pin, uint8_t value)
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{
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if (pin > 7)
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{
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_error = MCP23S08_PIN_ERROR;
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return false;
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}
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uint8_t IOR = MCP23S08_GPIO_A;
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uint8_t val = readReg(IOR);
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uint8_t pre = val;
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if (_error != MCP23S08_OK)
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{
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return false;
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}
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uint8_t mask = 1 << pin;
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if (value)
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{
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val |= mask;
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}
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else
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{
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val &= ~mask;
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}
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if (pre != val)
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{
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writeReg(IOR, val);
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if (_error != MCP23S08_OK)
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{
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return false;
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}
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}
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return true;
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}
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uint8_t MCP23S08::digitalRead(uint8_t pin)
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{
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if (pin > 7)
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{
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_error = MCP23S08_PIN_ERROR;
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return MCP23S08_INVALID_READ;
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}
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uint8_t IOR = MCP23S08_GPIO_A;
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uint8_t val = readReg(IOR);
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if (_error != MCP23S08_OK)
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{
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return MCP23S08_INVALID_READ;
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}
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uint8_t mask = 1 << pin;
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if (val & mask) return HIGH;
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return LOW;
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}
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// pin = 0..7
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// reversed = true or false
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bool MCP23S08::setPolarity(uint8_t pin, bool reversed)
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{
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if (pin > 7)
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{
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_error = MCP23S08_PIN_ERROR;
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return false;
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}
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uint8_t inputPolarityRegister = MCP23S08_POL_A;
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uint8_t val = readReg(inputPolarityRegister);
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if (_error != MCP23S08_OK)
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{
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return false;
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}
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uint8_t mask = 1 << pin;
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if (reversed)
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{
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val |= mask;
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}
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else
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{
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val &= ~mask;
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}
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writeReg(inputPolarityRegister, val);
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if (_error != MCP23S08_OK)
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{
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return false;
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}
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return true;
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}
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bool MCP23S08::getPolarity(uint8_t pin, bool &reversed)
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{
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if (pin > 7)
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{
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_error = MCP23S08_PIN_ERROR;
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return false;
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}
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uint8_t inputPolarityRegister = MCP23S08_POL_A;
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uint8_t val = readReg(inputPolarityRegister);
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if (_error != MCP23S08_OK)
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{
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return false;
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}
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uint8_t mask = 1 << pin;
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reversed = (val & mask) > 0;
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return true;
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}
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// pin = 0..7
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// pullup = true or false
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bool MCP23S08::setPullup(uint8_t pin, bool pullup)
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{
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if (pin > 7)
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{
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_error = MCP23S08_PIN_ERROR;
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return false;
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}
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uint8_t inputPullupRegister = MCP23S08_PUR_A;
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uint8_t val = readReg(inputPullupRegister);
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if (_error != MCP23S08_OK)
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{
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return false;
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}
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uint8_t mask = 1 << pin;
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if (pullup)
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{
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val |= mask;
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}
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else
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{
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val &= ~mask;
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}
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writeReg(inputPullupRegister, val);
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if (_error != MCP23S08_OK)
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{
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return false;
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}
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return true;
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}
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bool MCP23S08::getPullup(uint8_t pin, bool &pullup)
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{
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if (pin > 7)
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{
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_error = MCP23S08_PIN_ERROR;
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return false;
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}
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uint8_t inputPullupRegister = MCP23S08_PUR_A;
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uint8_t val = readReg(inputPullupRegister);
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if (_error != MCP23S08_OK)
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{
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return false;
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}
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uint8_t mask = 1 << pin;
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pullup = (val & mask) > 0;
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return true;
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}
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void MCP23S08::setSPIspeed(uint32_t speed)
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{
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_SPIspeed = speed;
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_spi_settings = SPISettings(_SPIspeed, MSBFIRST, SPI_MODE0);
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};
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///////////////////////////////////////////////////////////////////////
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//
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// 8 pins interface
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// whole register at once
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// value = 0..0xFF bit pattern
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bool MCP23S08::pinMode8(uint8_t value)
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{
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writeReg(MCP23S08_DDR_A, value);
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_error = MCP23S08_OK;
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return true;
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}
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bool MCP23S08::write8(uint8_t value)
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{
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writeReg(MCP23S08_GPIO_A, value);
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_error = MCP23S08_OK;
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return true;
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}
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int MCP23S08::read8()
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{
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_error = MCP23S08_OK;
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return readReg(MCP23S08_GPIO_A);
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}
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// mask = 0..0xFF bit pattern
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bool MCP23S08::setPolarity8(uint8_t mask)
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{
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writeReg(MCP23S08_POL_A, mask);
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if (_error != MCP23S08_OK)
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{
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return false;
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}
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return true;
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}
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bool MCP23S08::getPolarity8(uint8_t &mask)
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{
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mask = readReg(MCP23S08_POL_A);
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if (_error != MCP23S08_OK)
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{
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return false;
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}
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return true;
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}
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// mask = 0..0xFF bit pattern
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bool MCP23S08::setPullup8(uint8_t mask)
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{
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writeReg(MCP23S08_PUR_A, mask);
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if (_error != MCP23S08_OK)
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{
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return false;
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}
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return true;
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}
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bool MCP23S08::getPullup8(uint8_t &mask)
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{
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mask = readReg(MCP23S08_PUR_A);
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if (_error != MCP23S08_OK)
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{
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return false;
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}
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return true;
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}
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int MCP23S08::lastError()
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{
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int e = _error;
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_error = MCP23S08_OK; // reset error after read.
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return e;
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}
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////////////////////////////////////////////////////
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//
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// PRIVATE
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//
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bool MCP23S08::writeReg(uint8_t reg, uint8_t value)
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{
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_error = MCP23S08_OK;
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if (reg > MCP23S08_OLAT_A)
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{
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_error = MCP23S08_REGISTER_ERROR;
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return false;
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}
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::digitalWrite(_select, LOW);
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if (_hwSPI)
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{
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mySPI->beginTransaction(_spi_settings);
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mySPI->transfer(MCP23S08_WRITE_REG | (_address << 1) );
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mySPI->transfer(reg);
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mySPI->transfer(value);
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mySPI->endTransaction();
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}
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else
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{
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swSPI_transfer(MCP23S08_WRITE_REG | (_address << 1) );
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swSPI_transfer(reg);
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swSPI_transfer(value);
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}
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::digitalWrite(_select, HIGH);
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return true;
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}
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uint8_t MCP23S08::readReg(uint8_t reg)
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{
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uint8_t rv = 0;
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_error = MCP23S08_OK;
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if (reg > MCP23S08_OLAT_A)
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{
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_error = MCP23S08_REGISTER_ERROR;
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return false;
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}
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::digitalWrite(_select, LOW);
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if (_hwSPI)
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{
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mySPI->beginTransaction(_spi_settings);
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mySPI->transfer(MCP23S08_READ_REG | (_address << 1) ); // TODO OPTIMIZE n times
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mySPI->transfer(reg);
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rv = mySPI->transfer(0xFF);
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mySPI->endTransaction();
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}
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else
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{
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swSPI_transfer(MCP23S08_READ_REG | (_address << 1) );
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swSPI_transfer(reg);
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rv = swSPI_transfer(0xFF);
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}
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::digitalWrite(_select, HIGH);
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return rv;
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}
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uint8_t MCP23S08::swSPI_transfer(uint8_t value)
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{
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uint8_t clk = _clock;
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uint8_t dao = _dataOut;
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uint8_t dai = _dataIn;
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uint8_t rv = 0;
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for (uint8_t mask = 0x80; mask > 0; mask >>= 1)
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{
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::digitalWrite(dao, (value & mask) ? HIGH : LOW);
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::digitalWrite(clk, HIGH);
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if (::digitalRead(dai) == HIGH) rv |= mask;
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::digitalWrite(clk, LOW);
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}
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return rv;
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}
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// -- END OF FILE --
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