mirror of
https://github.com/DCC-EX/CommandStation-EX.git
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Merge branch 'devel-nmck' of https://github.com/DCC-EX/CommandStation-EX into devel-nmck
This commit is contained in:
Neil McKechnie
commit
8083bd1b3b
@ -35,6 +35,9 @@
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#elif defined(ARDUINO_ARCH_SAMD)
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#include "I2CManager_NonBlocking.h"
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#include "I2CManager_SAMD.h" // SAMD21 for now... SAMD51 as well later
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#elif defined(ARDUINO_ARCH_STM32)
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#include "I2CManager_NonBlocking.h"
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#include "I2CManager_STM32.h" // STM32F411RE for now... more later
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#else
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#define I2C_USE_WIRE
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#include "I2CManager_Wire.h" // Other platforms
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265
I2CManager_STM32.h
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265
I2CManager_STM32.h
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@ -0,0 +1,265 @@
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/*
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* © 2022-23 Paul M Antoine
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* © 2023, Neil McKechnie
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* All rights reserved.
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*
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* This file is part of CommandStation-EX
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*
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* This is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* It is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with CommandStation. If not, see <https://www.gnu.org/licenses/>.
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*/
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#ifndef I2CMANAGER_STM32_H
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#define I2CMANAGER_STM32_H
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#include <Arduino.h>
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#include "I2CManager.h"
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//#include <avr/io.h>
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//#include <avr/interrupt.h>
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#include <wiring_private.h>
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/***************************************************************************
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* Interrupt handler.
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* IRQ handler for SERCOM3 which is the default I2C definition for Arduino Zero
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* compatible variants such as the Sparkfun SAMD21 Dev Breakout etc.
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* Later we may wish to allow use of an alternate I2C bus, or more than one I2C
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* bus on the SAMD architecture
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***************************************************************************/
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#if defined(I2C_USE_INTERRUPTS) && defined(ARDUINO_ARCH_STM32)
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void I2C1_IRQHandler() {
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I2CManagerClass::handleInterrupt();
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}
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#endif
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// Assume I2C1 for now - default I2C bus on Nucleo-F411RE and likely Nucleo-64 variants
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I2C_TypeDef *s = I2C1;
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#define I2C_IRQn I2C1_EV_IRQn
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/***************************************************************************
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* Set I2C clock speed register. This should only be called outside of
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* a transmission. The I2CManagerClass::_setClock() function ensures
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* that it is only called at the beginning of an I2C transaction.
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***************************************************************************/
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void I2CManagerClass::I2C_setClock(uint32_t i2cClockSpeed) {
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// Calculate a rise time appropriate to the requested bus speed
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int t_rise;
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if (i2cClockSpeed < 200000L) {
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i2cClockSpeed = 100000L;
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t_rise = 1000;
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} else if (i2cClockSpeed < 800000L) {
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i2cClockSpeed = 400000L;
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t_rise = 300;
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} else if (i2cClockSpeed < 1200000L) {
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i2cClockSpeed = 1000000L;
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t_rise = 120;
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} else {
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i2cClockSpeed = 100000L;
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t_rise = 1000;
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}
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// Disable the I2C master mode and wait for sync
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// s->I2CM.CTRLA.bit.ENABLE = 0 ;
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// while (s->I2CM.SYNCBUSY.bit.ENABLE != 0);
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// Calculate baudrate - using a rise time appropriate for the speed
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// s->I2CM.BAUD.bit.BAUD = SystemCoreClock / (2 * i2cClockSpeed) - 5 - (((SystemCoreClock / 1000000) * t_rise) / (2 * 1000));
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// Enable the I2C master mode and wait for sync
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// s->I2CM.CTRLA.bit.ENABLE = 1 ;
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// while (s->I2CM.SYNCBUSY.bit.ENABLE != 0);
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// Setting bus idle mode and wait for sync
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// s->I2CM.STATUS.bit.BUSSTATE = 1 ;
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// while (s->I2CM.SYNCBUSY.bit.SYSOP != 0);
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}
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/***************************************************************************
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* Initialise I2C registers.
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***************************************************************************/
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void I2CManagerClass::I2C_init()
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{
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//Setting up the clocks
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RCC->APB1ENR |= (1<<21); // Enable I2C CLOCK
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RCC->AHB1ENR |= (1<<1); // Enable GPIOB CLOCK for PB8/PB9
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// Standard I2C pins are SCL on PB8 and SDA on PB9
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// Bits (17:16)= 1:0 --> Alternate Function for Pin PB8;
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// Bits (19:18)= 1:0 --> Alternate Function for Pin PB9
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GPIOB->MODER |= (2<<(8*2)) | (2<<(9*2)); // PB8 and PB9 set to ALT function
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GPIOB->OTYPER |= (1<<8) | (1<<9); // PB8 and PB9 set to open drain output capability
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GPIOB->OSPEEDR |= (3<<(8*2)) | (3<<(9*2)); // PB8 and PB9 set to High Speed mode
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GPIOB->PUPDR |= (1<<(8*2)) | (1<<(9*2)); // PB8 and PB9 set to pull-up capability
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// Alt Function High register routing pins PB8 and PB9 for I2C1:
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// Bits (3:2:1:0) = 0:1:0:0 --> AF4 for pin PB8
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// Bits (7:6:5:4) = 0:1:0:0 --> AF4 for pin PB9
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GPIOB->AFR[1] |= (4<<0) | (4<<4); // PB8 on low nibble, PB9 on next nibble up
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// Software reset the I2C peripheral
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s->CR1 |= (1<<15); // reset the I2C
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s->CR1 &= ~(1<<15); // Normal operation
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// Program the peripheral input clock in CR2 Register in order to generate correct timings
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s->CR2 |= (16<<0); // PCLK1 FREQUENCY in MHz
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#if defined(I2C_USE_INTERRUPTS)
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// Setting NVIC
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NVIC_SetPriority(I2C_IRQn, 1); // Match default priorities
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NVIC_EnableIRQ(I2C_IRQn);
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// CR2 Interrupt Settings
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// Bit 15-13: reserved
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// Bit 12: LAST - DMA last transfer
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// Bit 11: DMAEN - DMA enable
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// Bit 10: ITBUFEN - Buffer interrupt enable
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// Bit 9: ITEVTEN - Event interrupt enable
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// Bit 8: ITERREN - Error interrupt enable
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// Bit 7-6: reserved
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// Bit 5-0: FREQ - Peripheral clock frequency (max 50MHz)
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s->CR2 |= 0x0700; // Enable Buffer, Event and Error interrupts
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#endif
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// Calculate baudrate and set default rate for now
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// Configure the Clock Control Register for 100KHz SCL frequency
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// Bit 15: I2C Master mode, 0=standard, 1=Fast Mode
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// Bit 14: Duty, fast mode duty cycle
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// Bit 11-0: FREQR = 16MHz => TPCLK1 = 62.5ns, so CCR divisor must be 0x50 (80 * 62.5ns = 5000ns)
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s->CCR = 0x0050;
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// Configure the rise time register - max allowed in 1000ns
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s->TRISE = 0x0011; // 1000 ns / 62.5 ns = 16 + 1
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// Enable the I2C master mode
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s->CR1 |= (1<<0); // Enable I2C
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// Setting bus idle mode and wait for sync
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}
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/***************************************************************************
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* Initiate a start bit for transmission.
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***************************************************************************/
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void I2CManagerClass::I2C_sendStart() {
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// Set counters here in case this is a retry.
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bytesToSend = currentRequest->writeLen;
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bytesToReceive = currentRequest->readLen;
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uint8_t temp;
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// On a single-master I2C bus, the start bit won't be sent until the bus
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// state goes to IDLE so we can request it without waiting. On a
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// multi-master bus, the bus may be BUSY under control of another master,
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// in which case we can avoid some arbitration failures by waiting until
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// the bus state is IDLE. We don't do that here.
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// If anything to send, initiate write. Otherwise initiate read.
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if (operation == OPERATION_READ || ((operation == OPERATION_REQUEST) && !bytesToSend))
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{
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// Send start for read operation
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s->CR1 |= (1<<10); // Enable the ACK
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s->CR1 |= (1<<8); // Generate START
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// Send address with read flag (1) or'd in
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s->DR = (currentRequest->i2cAddress << 1) | 1; // send the address
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while (!(s->SR1 & (1<<1))); // wait for ADDR bit to set
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// Special case for 1 byte reads!
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if (bytesToReceive == 1)
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{
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s->CR1 &= ~(1<<10); // clear the ACK bit
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temp = I2C1->SR1 | I2C1->SR2; // read SR1 and SR2 to clear the ADDR bit.... EV6 condition
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s->CR1 |= (1<<9); // Stop I2C
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}
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else
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temp = s->SR1 | s->SR2; // read SR1 and SR2 to clear the ADDR bit
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}
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else {
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// Send start for write operation
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s->CR1 |= (1<<10); // Enable the ACK
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s->CR1 |= (1<<8); // Generate START
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// Send address with write flag (0) or'd in
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s->DR = (currentRequest->i2cAddress << 1) | 0; // send the address
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while (!(s->SR1 & (1<<1))); // wait for ADDR bit to set
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temp = s->SR1 | s->SR2; // read SR1 and SR2 to clear the ADDR bit
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}
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}
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/***************************************************************************
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* Initiate a stop bit for transmission (does not interrupt)
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***************************************************************************/
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void I2CManagerClass::I2C_sendStop() {
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s->CR1 |= (1<<9); // Stop I2C
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}
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/***************************************************************************
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* Close I2C down
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***************************************************************************/
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void I2CManagerClass::I2C_close() {
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I2C_sendStop();
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// Disable the I2C master mode and wait for sync
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s->CR1 &= ~(1<<0); // Disable I2C peripheral
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// Should never happen, but wait for up to 500us only.
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unsigned long startTime = micros();
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while ((s->CR1 && 1) != 0) {
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if (micros() - startTime >= 500UL) break;
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}
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}
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/***************************************************************************
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* Main state machine for I2C, called from interrupt handler or,
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* if I2C_USE_INTERRUPTS isn't defined, from the I2CManagerClass::loop() function
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* (and therefore, indirectly, from I2CRB::wait() and I2CRB::isBusy()).
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***************************************************************************/
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void I2CManagerClass::I2C_handleInterrupt() {
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if (s->SR1 && (1<<9)) {
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// Arbitration lost, restart
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I2C_sendStart(); // Reinitiate request
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} else if (s->SR1 && (1<<8)) {
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// Bus error
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state = I2C_STATUS_BUS_ERROR;
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} else if (s->SR1 && (1<<7)) {
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// Master write completed
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if (s->SR1 && (1<<10)) {
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// Nacked, send stop.
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I2C_sendStop();
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state = I2C_STATUS_NEGATIVE_ACKNOWLEDGE;
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} else if (bytesToSend) {
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// Acked, so send next byte
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s->DR = currentRequest->writeBuffer[txCount++];
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bytesToSend--;
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} else if (bytesToReceive) {
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// Last sent byte acked and no more to send. Send repeated start, address and read bit.
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// s->I2CM.ADDR.bit.ADDR = (currentRequest->i2cAddress << 1) | 1;
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} else {
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// Check both TxE/BTF == 1 before generating stop
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while (!(s->SR1 && (1<<7))); // Check TxE
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while (!(s->SR1 && (1<<2))); // Check BTF
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// No more data to send/receive. Initiate a STOP condition.
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I2C_sendStop();
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state = I2C_STATUS_OK; // Done
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}
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} else if (s->SR1 && (1<<6)) {
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// Master read completed without errors
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if (bytesToReceive == 1) {
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// s->I2CM.CTRLB.bit.ACKACT = 1; // NAK final byte
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I2C_sendStop(); // send stop
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currentRequest->readBuffer[rxCount++] = s->DR; // Store received byte
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bytesToReceive = 0;
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state = I2C_STATUS_OK; // done
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} else if (bytesToReceive) {
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// s->I2CM.CTRLB.bit.ACKACT = 0; // ACK all but final byte
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currentRequest->readBuffer[rxCount++] = s->DR; // Store received byte
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bytesToReceive--;
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}
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}
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}
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#endif /* I2CMANAGER_STM32_H */
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