1-Wire: remove misleading parasitic power function, add byte function
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444534e214
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@ -15,7 +15,7 @@
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/** library for 1-wire protocol as master (code)
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* @file onewire_master.c
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* @author King Kévin <kingkevin@cuvoodoo.info>
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* @date 2017
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* @date 2017-2018
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* @note peripherals used: timer @ref onewire_master_timer, GPIO @ref onewire_master_gpio
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* @note overdrive mode is not provided
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* @implements 1-Wire protocol description from Book of iButton Standards
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@ -43,14 +43,6 @@
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#define ONEWIRE_MASTER_TIMER 2 /**< timer ID */
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/** @} */
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/** @defgroup onewire_master_gpio GPIO used for 1-wire signal
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* @note external pull-up resistor on pin is required (< 5 kOhm)
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* @{
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*/
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#define ONEWIRE_MASTER_PORT A /**< GPIO port */
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#define ONEWIRE_MASTER_PIN 4 /**< GPIO pin */
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/** @} */
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/** state of 1-Wire communication */
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volatile enum {
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ONEWIRE_STATE_IDLE, /**< no current communication */
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@ -67,43 +59,30 @@ static volatile bool slave_presence = false; /**< if slaves have been detected *
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static uint8_t* buffer = NULL; /**< input/output buffer for read/write commands/functions */
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static uint32_t buffer_size = 0; /**< size of buffer in bits */
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static volatile uint32_t buffer_bit = 0; /**< number of bits read/written */
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static bool onewire_master_parasite = false; /**< if parasite power should be provided whenever the is no communication */
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static uint16_t onewire_master_recovery = 0; /**< the recovery time in us (1 < Trec) */
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void onewire_master_setup(bool parasite, uint16_t recovery)
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void onewire_master_setup(void)
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{
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// setup GPIO with external interrupt
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rcc_periph_clock_enable(RCC_GPIO(ONEWIRE_MASTER_PORT)); // enable clock for GPIO peripheral
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gpio_set(GPIO(ONEWIRE_MASTER_PORT),GPIO(ONEWIRE_MASTER_PIN)); // idle is high (using pull-up resistor)
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onewire_master_parasite = parasite; // save if we should provide parasite power
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// setup GPIO pin as output (master starts communication before slave replies)
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if (onewire_master_parasite) {
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gpio_set_mode(GPIO(ONEWIRE_MASTER_PORT), GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO(ONEWIRE_MASTER_PIN)); // provide parasite power (external pull-up resistor is still require for communication)
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} else {
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gpio_set_mode(GPIO(ONEWIRE_MASTER_PORT), GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(ONEWIRE_MASTER_PIN)); // normal 1-Wire communication (only using external pull-up resistor)
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}
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// setup timer to generate/measure signal timing
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rcc_periph_clock_enable(RCC_TIM(ONEWIRE_MASTER_TIMER)); // enable clock for timer peripheral
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timer_reset(TIM(ONEWIRE_MASTER_TIMER)); // reset timer state
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timer_disable_counter(TIM(ONEWIRE_MASTER_TIMER)); // disable timer to configure it
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timer_set_mode(TIM(ONEWIRE_MASTER_TIMER), TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_UP); // set timer mode, use undivided timer clock, edge alignment (simple count), and count up
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timer_set_prescaler(TIM(ONEWIRE_MASTER_TIMER), 1-1); // don't use prescale since this 16 bits timer allows to wait > 480 us used for the reset pulse ( 1/(72E6/1/(2**16))=910us )
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// use comparator to time signal (without using the output), starting at slot start
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timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC1IF); // clear flag
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timer_set_oc_value(TIM(ONEWIRE_MASTER_TIMER), TIM_OC1, 1*(rcc_ahb_frequency/1000000)-1); // use compare function to time master pulling low when reading (1 < Tlowr < 15)
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timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC2IF); // clear flag
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timer_set_oc_value(TIM(ONEWIRE_MASTER_TIMER), TIM_OC2, 7*(rcc_ahb_frequency/1000000)-1); // use compare function to read or write 0 or 1 (1 < Trw < 15)
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timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC3IF); // clear flag
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timer_set_oc_value(TIM(ONEWIRE_MASTER_TIMER), TIM_OC3, 62*(rcc_ahb_frequency/1000000)-1); // use compare function to end time slot (60 < Tslot < 120), this will be followed by a recovery time (end of timer)
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timer_set_oc_value(TIM(ONEWIRE_MASTER_TIMER), TIM_OC4, (70-10)*(rcc_ahb_frequency/1000000)-1); // use compare function to detect slave presence (15 < Tpdh < 60 + 60 < Tpdl < 240), with hand tunig
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onewire_master_recovery = 5; // set minimum recovery time
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if (recovery>onewire_master_recovery) {
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onewire_master_recovery = recovery; // save desired recovery time
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}
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if (UINT16_MAX/onewire_master_recovery<(rcc_ahb_frequency/1000000)) { // catch integer overflow
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onewire_master_recovery = UINT16_MAX; // save maximum value
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} else {
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onewire_master_recovery *= (rcc_ahb_frequency/1000000); // save actual recovery time value
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}
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timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC4IF); // clear flag
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timer_set_oc_value(TIM(ONEWIRE_MASTER_TIMER), TIM_OC4, (70-10)*(rcc_ahb_frequency/1000000)-1); // use compare function to detect slave presence (15 < Tpdh < 60 + 60 < Tpdl < 240), with hand tuning
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timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_UIF); // clear update (overflow) flag
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timer_update_on_overflow(TIM(ONEWIRE_MASTER_TIMER)); // only use counter overflow as UEV source (use overflow as start time or timeout)
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timer_enable_irq(TIM(ONEWIRE_MASTER_TIMER), TIM_DIER_UIE); // enable update interrupt for overflow
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@ -113,6 +92,17 @@ void onewire_master_setup(bool parasite, uint16_t recovery)
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onewire_master_state = ONEWIRE_STATE_IDLE; // reset state
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}
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void onewire_master_release(void)
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{
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// release timer
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timer_disable_counter(TIM(ONEWIRE_MASTER_TIMER)); // disable timer
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timer_reset(TIM(ONEWIRE_MASTER_TIMER)); // reset timer state
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rcc_periph_clock_disable(RCC_TIM(ONEWIRE_MASTER_TIMER)); // disable clock for timer peripheral
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// release GPIO
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gpio_set_mode(GPIO(ONEWIRE_MASTER_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(ONEWIRE_MASTER_PIN)); // put back to input floating
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}
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bool onewire_master_reset(void)
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{
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// prepare timer
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@ -149,13 +139,7 @@ static bool onewire_master_write(void)
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// prepare timer
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timer_disable_counter(TIM(ONEWIRE_MASTER_TIMER)); // disable timer to reconfigure it
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timer_set_counter(TIM(ONEWIRE_MASTER_TIMER), 0); // reset counter
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uint16_t timeout = TIM_CCR3(TIM(ONEWIRE_MASTER_TIMER)); // time until new slot (= end of slot+recovery)
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if (UINT16_MAX-timeout<onewire_master_recovery) { // catch integer overflow
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timeout = UINT16_MAX; // set maximum value
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} else {
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timeout += onewire_master_recovery; // add recovery time to end of slot
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}
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timer_set_period(TIM(ONEWIRE_MASTER_TIMER), timeout-1); // set time for new time slot (Trec>1, after time slot end and recovery time)
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timer_set_period(TIM(ONEWIRE_MASTER_TIMER), TIM_CCR3(TIM(ONEWIRE_MASTER_TIMER))+2*(rcc_ahb_frequency/1000000)); // set time for new time slot (recovery timer Trec>1, after time slot end )
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timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC2IF); // clear output compare flag
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timer_enable_irq(TIM(ONEWIRE_MASTER_TIMER), TIM_DIER_CC2IE); // enable compare interrupt for bit setting
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timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC3IF); // clear output compare flag
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@ -189,13 +173,7 @@ static bool onewire_master_read(void)
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// prepare timer
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timer_disable_counter(TIM(ONEWIRE_MASTER_TIMER)); // disable timer to reconfigure it
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timer_set_counter(TIM(ONEWIRE_MASTER_TIMER), 0); // reset counter
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uint16_t timeout = TIM_CCR3(TIM(ONEWIRE_MASTER_TIMER)); // time until new slot (= end of slot+recovery)
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if (UINT16_MAX-timeout<onewire_master_recovery) { // catch integer overflow
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timeout = UINT16_MAX; // set maximum value
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} else {
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timeout += onewire_master_recovery; // add recovery time to end of slot
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}
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timer_set_period(TIM(ONEWIRE_MASTER_TIMER), timeout-1); // set time for new time slot (Trec>1, after time slot end and recovery time)
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timer_set_period(TIM(ONEWIRE_MASTER_TIMER), TIM_CCR3(TIM(ONEWIRE_MASTER_TIMER))+2*(rcc_ahb_frequency/1000000)); // set time for new time slot (recovery timer Trec>1, after time slot end )
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timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC1IF); // clear output compare flag
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timer_enable_irq(TIM(ONEWIRE_MASTER_TIMER), TIM_DIER_CC1IE); // enable compare interrupt for stop pulling low
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timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC2IF); // clear output compare flag
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@ -236,12 +214,36 @@ uint8_t onewire_master_crc(uint8_t* data, uint32_t length)
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return crc;
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}
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bool onewire_master_read_byte(uint8_t* data)
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{
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if (NULL==data) { // check input
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return false; // wrong input
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}
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// read data
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buffer_size = 8; // save number of bits to read (1 byte)
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buffer = data; // set the buffer to the data to write
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if (!onewire_master_read()) { // read bits from slave
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return false; // an error occurred
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}
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return true;
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}
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bool onewire_master_write_byte(uint8_t data)
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{
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// send data byte
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buffer_size = 8; // function command is only one byte
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buffer = &data; // set the buffer to the function code
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if (!onewire_master_write()) { // send command
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return false; // an error occurred
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}
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return true;
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}
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bool onewire_master_function_read(uint8_t function, uint8_t* data, uint32_t bits)
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{
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// send function command
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buffer_size = 8; // function command is only one byte
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buffer = &function; // set the buffer to the function code
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if (!onewire_master_write()) { // send command
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if (!onewire_master_write_byte(function)) {
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return false; // an error occurred
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}
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@ -262,9 +264,7 @@ bool onewire_master_function_read(uint8_t function, uint8_t* data, uint32_t bits
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bool onewire_master_function_write(uint8_t function, uint8_t* data, uint32_t bits)
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{
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// send function command
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buffer_size = 8; // function command is only one byte
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buffer = &function; // set the buffer to the function code
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if (!onewire_master_write()) { // send command
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if (!onewire_master_write_byte(function)) {
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return false; // an error occurred
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}
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@ -346,7 +346,7 @@ bool onewire_master_rom_search(uint64_t* code, bool alarm)
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goto end; // an error has occurred
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}
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buffer_size = 1; // to send next bit
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buffer[0] = (*code>>bit); // set bit to send
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buffer[0] = ((*code)>>bit); // set bit to send
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if (!onewire_master_write()) { // send bit
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goto end; // an error has occurred
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}
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@ -354,7 +354,7 @@ bool onewire_master_rom_search(uint64_t* code, bool alarm)
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// verify ROM code
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uint8_t rom_code[8] = {0}; // to store ROM code
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for (uint8_t i=0; i<LENGTH(rom_code); i++) {
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rom_code[i] = *code>>(8*i); // split and save last code in ROM code
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rom_code[i] = (*code)>>(8*i); // split and save last code in ROM code
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}
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if (onewire_master_crc(rom_code, LENGTH(rom_code))) { // verify checksum
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*code = 0; // return the last code found since it's valid
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@ -389,7 +389,6 @@ bool onewire_master_rom_match(uint64_t code)
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return true;
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}
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/** interrupt service routine called for timer */
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void TIM_ISR(ONEWIRE_MASTER_TIMER)(void)
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{
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@ -428,11 +427,6 @@ void TIM_ISR(ONEWIRE_MASTER_TIMER)(void)
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gpio_set(GPIO(ONEWIRE_MASTER_PORT),GPIO(ONEWIRE_MASTER_PIN)); // pull signal high (idle state)
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onewire_master_state = ONEWIRE_STATE_ERROR; // indicate error
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}
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if (onewire_master_parasite && (ONEWIRE_STATE_ERROR==onewire_master_state || ONEWIRE_STATE_DONE==onewire_master_state)) {
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gpio_set_mode(GPIO(ONEWIRE_MASTER_PORT), GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO(ONEWIRE_MASTER_PIN)); // provide parasite power
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} else {
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gpio_set_mode(GPIO(ONEWIRE_MASTER_PORT), GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(ONEWIRE_MASTER_PIN)); // normal 1-Wire communication (only using external pull-up resistor)
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}
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} else if (timer_get_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC1IF)) { // compare event happened for master pull low end for read
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timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC1IF); // clear flag
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switch (onewire_master_state) {
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@ -475,9 +469,6 @@ void TIM_ISR(ONEWIRE_MASTER_TIMER)(void)
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} else if (timer_get_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC3IF)) { // compare event happened for end to time slot
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timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC3IF); // clear flag
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gpio_set(GPIO(ONEWIRE_MASTER_PORT),GPIO(ONEWIRE_MASTER_PIN)); // pull signal high to end time slot
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if (onewire_master_parasite) { // provide power during recovery time
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gpio_set_mode(GPIO(ONEWIRE_MASTER_PORT), GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO(ONEWIRE_MASTER_PIN)); // provide parasite power
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}
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} else if (timer_get_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC4IF)) { // compare event happened for slave presence detection
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timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC4IF); // clear flag
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if (gpio_get(GPIO(ONEWIRE_MASTER_PORT),GPIO(ONEWIRE_MASTER_PIN))) { // check is a slave let its presence know by pulling low
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@ -15,18 +15,26 @@
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/** library for 1-wire protocol as master (API)
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* @file onewire_master.h
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* @author King Kévin <kingkevin@cuvoodoo.info>
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* @date 2017
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* @date 2017-2018
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* @note peripherals used: timer @ref onewire_master_timer, GPIO @ref onewire_master_gpio
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* @note overdrive mode is not provided
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*/
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#pragma once
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/** setup 1-wire peripheral
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* @param[in] parasite enable parasite power (provide power over 1-Wire line when not communicating)
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* @warning multiple masters and interrupts are prevented when parasite power is used
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* @param[in] recovery recovery time in us between timeslot, e.g. to ensure enough parasite power is provided (0 if not required)
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/** @defgroup onewire_master_gpio GPIO used for 1-wire signal
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* @note external pull-up resistor on pin is required (< 5 kOhm)
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* @{
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*/
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void onewire_master_setup(bool parasite, uint16_t recovery);
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#define ONEWIRE_MASTER_PORT C /**< GPIO port */
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#define ONEWIRE_MASTER_PIN 9 /**< GPIO pin */
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/** @} */
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/** setup 1-wire peripheral
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*/
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void onewire_master_setup(void);
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/** release 1-wire peripheral
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*/
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void onewire_master_release(void);
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/** send reset pulse
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* @return if slaves have indicated their presence
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*/
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@ -62,6 +70,18 @@ bool onewire_master_rom_skip(void);
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* @return if operation succeeded
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*/
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bool onewire_master_rom_match(uint64_t code);
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/** read data byte
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* @note it is up to the user to send the reset pulse
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* @param[out] data buffer to save data read
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* @return if operation succeeded
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*/
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bool onewire_master_read_byte(uint8_t* data);
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/** write data byte
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* @note it is up to the user to send the reset pulse
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* @param[in] data byte to write
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* @return if operation succeeded
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*/
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bool onewire_master_write_byte(uint8_t data);
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/** issue function and read data
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* @note user needs to send a ROM command before
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* @param[in] function function command to send
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