uart_soft.c
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/* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
/* standard libraries */
#include <stdint.h> // standard integer types
#include <stdlib.h> // general utilities
/* STM32 (including CM3) libraries */
#include <libopencm3/stm32/rcc.h> // real-time control clock library
#include <libopencm3/stm32/gpio.h> // general purpose input output library
#include <libopencm3/stm32/timer.h> // timer library
#include <libopencm3/cm3/nvic.h> // interrupt handler
#include <libopencm3/stm32/exti.h> // external interrupt defines
#include <libopencmsis/core_cm3.h> // Cortex M3 utilities
#include "uart_soft.h" // software UART library API
#include "global.h" // common methods
#define UART_SOFT_RX_PORT0 B
#define UART_SOFT_RX_PIN0 9
//#define UART_SOFT_RX_PORT1 A
//#define UART_SOFT_RX_PIN1 0
//#define UART_SOFT_RX_PORT2 A
//#define UART_SOFT_RX_PIN2 0
//#define UART_SOFT_RX_PORT3 A
//#define UART_SOFT_RX_PIN3 0
#define UART_SOFT_TX_PORT0 B
#define UART_SOFT_TX_PIN0 8
//#define UART_SOFT_TX_PORT1 A
//#define UART_SOFT_TX_PIN1 0
//#define UART_SOFT_TX_PORT2 A
//#define UART_SOFT_TX_PIN2 0
//#define UART_SOFT_TX_PORT3 A
//#define UART_SOFT_TX_PIN3 0
#define UART_SOFT_BUFFER 128
struct soft_uart_rx_state {
uint32_t port;
uint16_t pin;
uint32_t rcc;
uint32_t exti;
uint32_t irq;
uint32_t baudrate;
volatile uint16_t state;
volatile uint8_t bit;
volatile uint8_t byte;
volatile uint8_t buffer[UART_SOFT_BUFFER];
volatile uint8_t buffer_i;
volatile uint8_t buffer_used;
volatile bool lock;
volatile uint8_t buffer_byte;
volatile bool buffer_byte_used;
};
struct soft_uart_tx_state {
uint32_t port;
uint16_t pin;
uint32_t rcc;
uint32_t baudrate;
volatile uint8_t bit;
volatile uint8_t byte;
volatile uint8_t buffer[UART_SOFT_BUFFER];
volatile uint8_t buffer_i;
volatile uint8_t buffer_used;
volatile bool transmit;
};
static struct soft_uart_rx_state* uart_soft_rx_states[4] = {NULL};
static struct soft_uart_tx_state* uart_soft_tx_states[4] = {NULL};
volatile bool uart_soft_received[4] = {false, false, false, false};
#if (defined(UART_SOFT_RX_PORT0) && defined(UART_SOFT_RX_PIN0)) || (defined(UART_SOFT_RX_PORT1) && defined(UART_SOFT_RX_PIN1)) || (defined(UART_SOFT_RX_PORT2) && defined(UART_SOFT_RX_PIN2)) || (defined(UART_SOFT_RX_PORT3) && defined(UART_SOFT_RX_PIN0))
#define UART_SOFT_RX_TIMER 3
#endif
#if (defined(UART_SOFT_TX_PORT0) && defined(UART_SOFT_TX_PIN0)) || (defined(UART_SOFT_TX_PORT1) && defined(UART_SOFT_TX_PIN1)) || (defined(UART_SOFT_TX_PORT2) && defined(UART_SOFT_TX_PIN2)) || (defined(UART_SOFT_TX_PORT3) && defined(UART_SOFT_TX_PIN0))
#define UART_SOFT_TX_TIMER 4
#endif
static const uint32_t timer_flags[4] = {TIM_SR_CC1IF,TIM_SR_CC2IF,TIM_SR_CC3IF,TIM_SR_CC4IF};
static const uint32_t timer_interrupt[4] = {TIM_DIER_CC1IE,TIM_DIER_CC2IE,TIM_DIER_CC3IE,TIM_DIER_CC4IE};
static const enum tim_oc_id timer_oc[4] = {TIM_OC1,TIM_OC2,TIM_OC3,TIM_OC4};
bool uart_soft_setup(uint32_t *rx_baudrates, uint32_t *tx_baudrates)
{
(void)rx_baudrates; // ensure compile does no complain even if no receive port is used
(void)tx_baudrates; // ensure compile does no complain even if no transmit port is used
// save UART receive definition
#if defined(UART_SOFT_RX_PORT0) && defined(UART_SOFT_RX_PIN0)
uart_soft_rx_states[0] = calloc(1,sizeof(struct soft_uart_rx_state)); // create state definition
uart_soft_rx_states[0]->port = GPIO(UART_SOFT_RX_PORT0); // save receive port
uart_soft_rx_states[0]->pin = GPIO(UART_SOFT_RX_PIN0); // save receive pin
uart_soft_rx_states[0]->rcc = RCC_GPIO(UART_SOFT_RX_PORT0); // save receive port peripheral clock
uart_soft_rx_states[0]->exti = EXTI(UART_SOFT_RX_PIN0); // save receive external interrupt
uart_soft_rx_states[0]->irq = NVIC_EXTI_IRQ(UART_SOFT_RX_PIN0); // save receive interrupt request
#endif
// setup UART receive GPIO
for (uint8_t rx=0; rx<4; rx++) {
if (!uart_soft_rx_states[rx]) { // verify is receive UART is defined
continue; // skip configuration if not defined
}
if (!rx_baudrates || rx_baudrates[rx]==0) { // verify if receive baud rate has been defined
return false;
}
uart_soft_rx_states[rx]->baudrate = rx_baudrates[rx]; // save baud rate
rcc_periph_clock_enable(uart_soft_rx_states[rx]->rcc); // enable clock for GPIO peripheral
gpio_set_mode(uart_soft_rx_states[rx]->port, GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN, uart_soft_rx_states[rx]->pin); // setup GPIO pin UART receive
gpio_set(uart_soft_rx_states[rx]->port, uart_soft_rx_states[rx]->pin); // pull up to avoid noise when not connected
rcc_periph_clock_enable(RCC_AFIO); // enable alternate function clock for external interrupt
exti_select_source(uart_soft_rx_states[rx]->exti, uart_soft_rx_states[rx]->port); // mask external interrupt of this pin only for this port
exti_enable_request(uart_soft_rx_states[rx]->exti); // enable external interrupt
exti_set_trigger(uart_soft_rx_states[rx]->exti, EXTI_TRIGGER_BOTH); // trigger when button is pressed
nvic_enable_irq(uart_soft_rx_states[rx]->irq); // enable interrupt
uart_soft_rx_states[rx]->state = gpio_get(uart_soft_rx_states[rx]->port, uart_soft_rx_states[rx]->pin); // save state of GPIO
uart_soft_rx_states[rx]->bit = 0; // reset bits received
}
// save UART transmit definition
#if defined(UART_SOFT_TX_PORT0) && defined(UART_SOFT_TX_PIN0)
uart_soft_tx_states[0] = calloc(1,sizeof(struct soft_uart_tx_state)); // create state definition
uart_soft_tx_states[0]->port = GPIO(UART_SOFT_TX_PORT0); // save receive port
uart_soft_tx_states[0]->pin = GPIO(UART_SOFT_TX_PIN0); // save receive pin
uart_soft_tx_states[0]->rcc = RCC_GPIO(UART_SOFT_TX_PORT0); // save receive port peripheral clock
#endif
// setup UART transmit GPIO
for (uint8_t tx=0; tx<4; tx++) {
if (!uart_soft_tx_states[tx]) { // verify is transmit UART is defined
continue; // skip configuration if not defined
}
if (!tx_baudrates || tx_baudrates[tx]==0) { // verify if transmit baud rate has been defined
return false;
}
uart_soft_tx_states[tx]->baudrate = tx_baudrates[tx]; // save baud rate
rcc_periph_clock_enable(uart_soft_tx_states[tx]->rcc); // enable clock for GPIO peripheral
gpio_set_mode(uart_soft_tx_states[tx]->port, GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, uart_soft_tx_states[tx]->pin); // setup GPIO UART transmit pin
gpio_set(uart_soft_tx_states[tx]->port, uart_soft_tx_states[tx]->pin); // idle high
}
// setup timer
#if defined(UART_SOFT_RX_TIMER)
rcc_periph_clock_enable(RCC_TIM(UART_SOFT_RX_TIMER)); // enable clock for timer peripheral
timer_reset(TIM(UART_SOFT_RX_TIMER)); // reset timer state
timer_set_mode(TIM(UART_SOFT_RX_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
timer_set_prescaler(TIM(UART_SOFT_RX_TIMER), 0); // prescaler to be able to sample 2400-115200 bps (72MHz/2^16=1099<2400bps)
nvic_enable_irq(NVIC_TIM_IRQ(UART_SOFT_RX_TIMER)); // allow interrupt for timer
timer_enable_counter(TIM(UART_SOFT_RX_TIMER)); // start timer to generate interrupts for the receive pins
#endif
#if defined(UART_SOFT_TX_TIMER)
rcc_periph_clock_enable(RCC_TIM(UART_SOFT_TX_TIMER)); // enable clock for timer peripheral
timer_reset(TIM(UART_SOFT_TX_TIMER)); // reset timer state
timer_set_mode(TIM(UART_SOFT_TX_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
timer_set_prescaler(TIM(UART_SOFT_TX_TIMER), 0); // prescaler to be able to output 2400-115200 bps (72MHz/2^16=1099<2400bps)
nvic_enable_irq(NVIC_TIM_IRQ(UART_SOFT_TX_TIMER)); // allow interrupt for timer
timer_enable_counter(TIM(UART_SOFT_TX_TIMER)); // start timer to generate interrupts for the transmit pins
#endif
return true; // setup completed
}
#if defined(UART_SOFT_RX_TIMER)
uint8_t uart_soft_getbyte(uint8_t uart)
{
if (uart>=4 || !uart_soft_rx_states[uart]) { // ensure receive UART port is defined
return 0; // return
}
while (!uart_soft_rx_states[uart]->buffer_used) { // idle until data is available
__WFI(); // sleep until interrupt
}
uart_soft_rx_states[uart]->lock = true; // set lock
uint8_t to_return = uart_soft_rx_states[uart]->buffer[uart_soft_rx_states[uart]->buffer_i]; // get the next available character
uart_soft_rx_states[uart]->buffer_i = (uart_soft_rx_states[uart]->buffer_i+1)%LENGTH(uart_soft_rx_states[uart]->buffer); // update used buffer
uart_soft_rx_states[uart]->buffer_used--; // update used buffer
uart_soft_rx_states[uart]->lock = false; // free lock
if (uart_soft_rx_states[uart]->buffer_byte_used) { // temporary byte has been stored
uart_soft_rx_states[uart]->buffer[(uart_soft_rx_states[uart]->buffer_i+uart_soft_rx_states[uart]->buffer_used)%LENGTH(uart_soft_rx_states[uart]->buffer)] = uart_soft_rx_states[uart]->buffer_byte; // put byte in buffer
uart_soft_rx_states[uart]->buffer_used++; // update used buffer
uart_soft_rx_states[uart]->buffer_byte_used = false; // buffer byte is now in buffer
}
uart_soft_received[uart] = (uart_soft_rx_states[uart]->buffer_used!=0); // notify user if data is available
uart_soft_rx_states[uart]->lock = false; // free lock
return to_return;
}
void TIM_ISR(UART_SOFT_RX_TIMER)(void)
{
for (uint8_t rx=0; rx<4; rx++) {
if (timer_interrupt_source(TIM(UART_SOFT_RX_TIMER),timer_flags[rx])) { // got a match on compare for receive pin
timer_clear_flag(TIM(UART_SOFT_RX_TIMER),timer_flags[rx]); // clear flag
if (!uart_soft_rx_states[rx]) { // verify if RX exists
continue; // skip if receive port is not defined it
}
uart_soft_rx_states[rx]->byte += ((gpio_get(uart_soft_rx_states[rx]->port, uart_soft_rx_states[rx]->pin)==0 ? 0 : 1)<<(uart_soft_rx_states[rx]->bit-1)); // save bit value
if (uart_soft_rx_states[rx]->bit<8) { // not the last bit received
timer_set_oc_value(TIM(UART_SOFT_RX_TIMER),timer_oc[rx],timer_get_counter(TIM(UART_SOFT_RX_TIMER))+rcc_ahb_frequency/uart_soft_rx_states[rx]->baudrate); // set timer to next bit
uart_soft_rx_states[rx]->bit++; // wait for next bit
} else { // last bit received
if (uart_soft_rx_states[rx]->lock) { // someone is already reading data
uart_soft_rx_states[rx]->buffer_byte = uart_soft_rx_states[rx]->byte; // save byte
uart_soft_rx_states[rx]->buffer_byte_used = true; // notify reader there is a temporary byte
} else { // buffer can be updated
if (uart_soft_rx_states[rx]->buffer_used>=LENGTH(uart_soft_rx_states[rx]->buffer)) { // buffer is full
uart_soft_rx_states[rx]->buffer_i = (uart_soft_rx_states[rx]->buffer_i+1)%LENGTH(uart_soft_rx_states[rx]->buffer); // drop oldest byte
uart_soft_rx_states[rx]->buffer_used--; // update buffer usage
}
uart_soft_rx_states[rx]->buffer[(uart_soft_rx_states[rx]->buffer_i+uart_soft_rx_states[rx]->buffer_used)%LENGTH(uart_soft_rx_states[rx]->buffer)] = uart_soft_rx_states[rx]->byte; // put byte in buffer
uart_soft_rx_states[rx]->buffer_used++; // update used buffer
uart_soft_received[rx] = true; // notify user data is available
}
timer_disable_irq(TIM(UART_SOFT_RX_TIMER),timer_interrupt[rx]); // stop_interrupting
uart_soft_rx_states[rx]->bit = 0; // next bit should be first bit of next byte
}
}
}
}
#endif
#if defined(UART_SOFT_TX_TIMER)
void uart_soft_flush(uint8_t uart)
{
if (uart>=4 || !uart_soft_tx_states[uart]) { // ensure transmit UART port is defined
return; // return
}
while (uart_soft_tx_states[uart]->buffer_used) { // idle until buffer is empty
__WFI(); // sleep until interrupt
}
while (uart_soft_tx_states[uart]->transmit) { // idle until transmission is complete
__WFI(); // sleep until interrupt
}
}
static void uart_soft_transmit(uint8_t uart) {
if (uart>=4 || !uart_soft_tx_states[uart]) { // ensure transmit UART port is defined
return; // UART transmit port not defined
}
if (uart_soft_tx_states[uart]->transmit) { // already transmitting
return; // transmission is already ongoing
}
if (!uart_soft_tx_states[uart]->buffer_used) { // no buffered data to transmit
return; // nothing to transmit
}
uart_soft_tx_states[uart]->byte = uart_soft_tx_states[uart]->buffer[uart_soft_tx_states[uart]->buffer_i]; // get byte
uart_soft_tx_states[uart]->buffer_i = (uart_soft_tx_states[uart]->buffer_i+1)%LENGTH(uart_soft_tx_states[uart]->buffer); // update index
uart_soft_tx_states[uart]->buffer_used--; // update used buffer
uart_soft_tx_states[uart]->bit = 0; // LSb is transmitted first
uart_soft_tx_states[uart]->transmit = true; // start transmission
gpio_clear(uart_soft_tx_states[uart]->port, uart_soft_tx_states[uart]->pin); // output start bit
timer_set_oc_value(TIM(UART_SOFT_TX_TIMER), timer_oc[uart], timer_get_counter(TIM(UART_SOFT_TX_TIMER))+(rcc_ahb_frequency/uart_soft_tx_states[uart]->baudrate)); // set timer to output UART frame 1 (data bit 0) in 1 bit
timer_clear_flag(TIM(UART_SOFT_TX_TIMER), timer_flags[uart]); // clear flag before enabling interrupt
timer_enable_irq(TIM(UART_SOFT_TX_TIMER), timer_interrupt[uart]);// enable timer IRQ for TX for this UART
}
void uart_soft_putbyte_nonblocking(uint8_t uart, uint8_t byte)
{
if (uart>=4 || !uart_soft_tx_states[uart]) { // ensure transmit UART port is defined
return; // return
}
while (uart_soft_tx_states[uart]->buffer_used>=LENGTH(uart_soft_tx_states[uart]->buffer)) { // idle until there is place in the buffer
__WFI(); // sleep until something happened
}
uart_soft_tx_states[uart]->buffer[(uart_soft_tx_states[uart]->buffer_i+uart_soft_tx_states[uart]->buffer_used)%LENGTH(uart_soft_tx_states[uart]->buffer)] = byte; // save byte to be transmitted
uart_soft_tx_states[uart]->buffer_used++; // update used buffer
uart_soft_transmit(uart); // start transmission
}
void uart_soft_putbyte_blocking(uint8_t uart, uint8_t byte)
{
uart_soft_putbyte_nonblocking(uart, byte); // put byte in queue
uart_soft_flush(uart); // wait for all byte to be transmitted
}
void TIM_ISR(UART_SOFT_TX_TIMER)(void)
{
for (uint8_t tx=0; tx<4; tx++) {
if (timer_interrupt_source(TIM(UART_SOFT_TX_TIMER),timer_flags[tx])) { // got a match on compare for transmit pin
timer_clear_flag(TIM(UART_SOFT_TX_TIMER),timer_flags[tx]); // clear flag
if (!uart_soft_tx_states[tx]) { // verify if transmit is defined
continue; // skip if transmit port is not defined it
}
if (uart_soft_tx_states[tx]->bit<8) { // there is a data bit to transmit
if ((uart_soft_tx_states[tx]->byte>>uart_soft_tx_states[tx]->bit)&0x01) { // bit to transmit is a 1
gpio_set(uart_soft_tx_states[tx]->port, uart_soft_tx_states[tx]->pin); // set output to high
} else { // bit to transmit is a 0
gpio_clear(uart_soft_tx_states[tx]->port, uart_soft_tx_states[tx]->pin); // set output to low
}
timer_set_oc_value(TIM(UART_SOFT_TX_TIMER), timer_oc[tx], timer_get_counter(TIM(UART_SOFT_TX_TIMER))+(rcc_ahb_frequency/uart_soft_tx_states[tx]->baudrate)); // wait for the next frame bit
uart_soft_tx_states[tx]->bit++; // go to next bit
} else if (uart_soft_tx_states[tx]->bit==8) { // transmit stop bit
gpio_set(uart_soft_tx_states[tx]->port, uart_soft_tx_states[tx]->pin); // go idle high
timer_set_oc_value(TIM(UART_SOFT_TX_TIMER), timer_oc[tx], timer_get_counter(TIM(UART_SOFT_TX_TIMER))+(rcc_ahb_frequency/uart_soft_tx_states[tx]->baudrate)); // wait for 1 stop bit
uart_soft_tx_states[tx]->bit++; // go to next bit
} else { // UART frame is complete
timer_disable_irq(TIM(UART_SOFT_TX_TIMER), timer_interrupt[tx]);// enable timer IRQ for TX for this UART
uart_soft_tx_states[tx]->transmit = false; // transmission finished
uart_soft_transmit(tx); // start next transmission (if there is)
}
} // compare match
} // go through UARTs
}
#endif
static void uart_soft_receive_activity(void)
{
for (uint8_t rx=0; rx<4; rx++) {
if (!uart_soft_rx_states[rx]) { // verify if receive port is not configured
continue; // skip if receive port is not defined it
}
if (uart_soft_rx_states[rx]->state!=gpio_get(uart_soft_rx_states[rx]->port, uart_soft_rx_states[rx]->pin)) { // only do something if state changed
uart_soft_rx_states[rx]->state = gpio_get(uart_soft_rx_states[rx]->port, uart_soft_rx_states[rx]->pin); // save new state
if (uart_soft_rx_states[rx]->bit==0) { // start bit edge detected
if (uart_soft_rx_states[rx]->state==0) { // start bit has to be low
timer_set_oc_value(TIM(UART_SOFT_RX_TIMER), timer_oc[rx], timer_get_counter(TIM(UART_SOFT_RX_TIMER))+(rcc_ahb_frequency/uart_soft_rx_states[rx]->baudrate)*1.5); // set timer to sample data bit 0 in 1.5 bits
timer_clear_flag(TIM(UART_SOFT_RX_TIMER), timer_flags[rx]); // clear flag before enabling interrupt
timer_enable_irq(TIM(UART_SOFT_RX_TIMER), timer_interrupt[rx]);// enable timer IRQ for RX for this UART
uart_soft_rx_states[rx]->byte = 0; // reset byte value
uart_soft_rx_states[rx]->bit++; // wait for first bit
}
} else { // data bit detected
timer_set_oc_value(TIM(UART_SOFT_RX_TIMER), timer_oc[rx], timer_get_counter(TIM(UART_SOFT_RX_TIMER))+(rcc_ahb_frequency/uart_soft_rx_states[rx]->baudrate)/2); // resync timer to half a bit (good for drifting transmission, bad if the line is noisy)
}
}
}
}
#if (defined(UART_SOFT_RX_PORT0) && defined(UART_SOFT_RX_PIN0) && UART_SOFT_RX_PIN0==0) || (defined(UART_SOFT_RX_PORT1) && defined(UART_SOFT_RX_PIN1) && UART_SOFT_RX_PIN1==0) || (defined(UART_SOFT_RX_PORT2) && defined(UART_SOFT_RX_PIN2) && UART_SOFT_RX_PIN2==0) || (defined(UART_SOFT_RX_PORT3) && defined(UART_SOFT_RX_PIN3) && UART_SOFT_RX_PIN3==0)
void exti0_isr(void)
{
exti_reset_request(EXTI0); // clear interrupt flag for pin triggers this ISR (pin state will be checked independently)
uart_soft_receive_activity(); // check which GPIO changed
}
#endif
#if (defined(UART_SOFT_RX_PORT0) && defined(UART_SOFT_RX_PIN0) && UART_SOFT_RX_PIN0==1) || (defined(UART_SOFT_RX_PORT1) && defined(UART_SOFT_RX_PIN1) && UART_SOFT_RX_PIN1==1) || (defined(UART_SOFT_RX_PORT2) && defined(UART_SOFT_RX_PIN2) && UART_SOFT_RX_PIN2==1) || (defined(UART_SOFT_RX_PORT3) && defined(UART_SOFT_RX_PIN3) && UART_SOFT_RX_PIN3==1)
void exti1_isr(void)
{
exti_reset_request(EXTI1); // clear interrupt flag for pin triggers this ISR (pin state will be checked independently)
uart_soft_receive_activity(); // check which GPIO changed
}
#endif
#if (defined(UART_SOFT_RX_PORT0) && defined(UART_SOFT_RX_PIN0) && UART_SOFT_RX_PIN0==2) || (defined(UART_SOFT_RX_PORT1) && defined(UART_SOFT_RX_PIN1) && UART_SOFT_RX_PIN1==2) || (defined(UART_SOFT_RX_PORT2) && defined(UART_SOFT_RX_PIN2) && UART_SOFT_RX_PIN2==2) || (defined(UART_SOFT_RX_PORT3) && defined(UART_SOFT_RX_PIN3) && UART_SOFT_RX_PIN3==2)
void exti2_isr(void)
{
exti_reset_request(EXTI2); // clear interrupt flag for pin triggers this ISR (pin state will be checked independently)
uart_soft_receive_activity(); // check which GPIO changed
}
#endif
#if (defined(UART_SOFT_RX_PORT0) && defined(UART_SOFT_RX_PIN0) && UART_SOFT_RX_PIN0==3) || (defined(UART_SOFT_RX_PORT1) && defined(UART_SOFT_RX_PIN1) && UART_SOFT_RX_PIN1==3) || (defined(UART_SOFT_RX_PORT2) && defined(UART_SOFT_RX_PIN2) && UART_SOFT_RX_PIN2==3) || (defined(UART_SOFT_RX_PORT3) && defined(UART_SOFT_RX_PIN3) && UART_SOFT_RX_PIN3==3)
void exti3_isr(void)
{
exti_reset_request(EXTI3); // clear interrupt flag for pin triggers this ISR (pin state will be checked independently)
uart_soft_receive_activity(); // check which GPIO changed
}
#endif
#if (defined(UART_SOFT_RX_PORT0) && defined(UART_SOFT_RX_PIN0) && UART_SOFT_RX_PIN0==4) || (defined(UART_SOFT_RX_PORT1) && defined(UART_SOFT_RX_PIN1) && UART_SOFT_RX_PIN1==4) || (defined(UART_SOFT_RX_PORT2) && defined(UART_SOFT_RX_PIN2) && UART_SOFT_RX_PIN2==4) || (defined(UART_SOFT_RX_PORT3) && defined(UART_SOFT_RX_PIN3) && UART_SOFT_RX_PIN3==4)
void exti4_isr(void)
{
exti_reset_request(EXTI4); // clear interrupt flag for pin triggers this ISR (pin state will be checked independently)
uart_soft_receive_activity(); // check which GPIO changed
}
#endif
#if (defined(UART_SOFT_RX_PORT0) && defined(UART_SOFT_RX_PIN0) && (UART_SOFT_RX_PIN0==5 || UART_SOFT_RX_PIN0==6 || UART_SOFT_RX_PIN0==7 || UART_SOFT_RX_PIN0==8 || UART_SOFT_RX_PIN0==9)) || (defined(UART_SOFT_RX_PORT1) && defined(UART_SOFT_RX_PIN1) && (UART_SOFT_RX_PIN1==5 || UART_SOFT_RX_PIN1==6 || UART_SOFT_RX_PIN1==7 || UART_SOFT_RX_PIN1==8 || UART_SOFT_RX_PIN1==9)) || (defined(UART_SOFT_RX_PORT2) && defined(UART_SOFT_RX_PIN2) && (UART_SOFT_RX_PIN2==5 || UART_SOFT_RX_PIN2==6 || UART_SOFT_RX_PIN2==7 || UART_SOFT_RX_PIN2==8 || UART_SOFT_RX_PIN2==9)) || (defined(UART_SOFT_RX_PORT3) && defined(UART_SOFT_RX_PIN3) && (UART_SOFT_RX_PIN3==5 || UART_SOFT_RX_PIN3==6 || UART_SOFT_RX_PIN3==7 || UART_SOFT_RX_PIN3==8 || UART_SOFT_RX_PIN3==9))
void exti9_5_isr(void)
{
exti_reset_request(EXTI5|EXTI6|EXTI7|EXTI8|EXTI9); // clear interrupt flag for pin triggers this ISR (pin state will be checked independently)
uart_soft_receive_activity(); // check which GPIO changed
}
#endif
#if (defined(UART_SOFT_RX_PORT0) && defined(UART_SOFT_RX_PIN0) && (UART_SOFT_RX_PIN0==10 || UART_SOFT_RX_PIN0==11 || UART_SOFT_RX_PIN0==12 || UART_SOFT_RX_PIN0==13 || UART_SOFT_RX_PIN0==14 || UART_SOFT_RX_PIN0==15)) || (defined(UART_SOFT_RX_PORT1) && defined(UART_SOFT_RX_PIN1) && (UART_SOFT_RX_PIN1==10 || UART_SOFT_RX_PIN1==11 || UART_SOFT_RX_PIN1==12 || UART_SOFT_RX_PIN1==13 || UART_SOFT_RX_PIN1==14 || UART_SOFT_RX_PIN1==15)) || (defined(UART_SOFT_RX_PORT2) && defined(UART_SOFT_RX_PIN2) && (UART_SOFT_RX_PIN2==10 || UART_SOFT_RX_PIN2==11 || UART_SOFT_RX_PIN2==12 || UART_SOFT_RX_PIN2==13 || UART_SOFT_RX_PIN2==14 || UART_SOFT_RX_PIN2==15)) || (defined(UART_SOFT_RX_PORT3) && defined(UART_SOFT_RX_PIN3) && (UART_SOFT_RX_PIN3==10 || UART_SOFT_RX_PIN3==11 || UART_SOFT_RX_PIN3==12 || UART_SOFT_RX_PIN3==13 || UART_SOFT_RX_PIN3==14 || UART_SOFT_RX_PIN3==15))
void exti15_10_isr(void)
{
exti_reset_request(EXTI10|EXTI11|EXTI12|EXTI13|EXTI14|EXTI15); // clear interrupt flag for pin triggers this ISR (pin state will be checked independently)
uart_soft_receive_activity(); // check which GPIO changed
}
#endif
uart_soft_putbyte_nonblocking
void uart_soft_putbyte_nonblocking(uint8_t uart, uint8_t byte)
put byte in buffer to be transmitted on UART port
Definition: uart_soft.c:290
TIM_ISR
#define TIM_ISR(x)
get interrupt service routine for timer base on TIM identifier
Definition: global.h:113
soft_uart_rx_state::exti
uint32_t exti
UART receive external interrupt.
Definition: uart_soft.c:67
RCC_GPIO
#define RCC_GPIO(x)
get RCC for GPIO based on GPIO identifier
Definition: global.h:105
soft_uart_rx_state::buffer_byte_used
volatile bool buffer_byte_used
signal a byte has been stored in temporary buffer
Definition: uart_soft.c:78
UART_SOFT_RX_PORT0
#define UART_SOFT_RX_PORT0
port for receive signal for UART port 0
Definition: uart_soft.c:42
soft_uart_tx_state::baudrate
uint32_t baudrate
UART receive baud rate.
Definition: uart_soft.c:86
soft_uart_tx_state::rcc
uint32_t rcc
UART receive port peripheral clock.
Definition: uart_soft.c:85
NVIC_TIM_IRQ
#define NVIC_TIM_IRQ(x)
get NVIC IRQ for timer base on TIM identifier
Definition: global.h:111
uart_soft_flush
void uart_soft_flush(uint8_t uart)
ensure all bytes are transmitted for the UART
Definition: uart_soft.c:253
soft_uart_tx_state::transmit
volatile bool transmit
flag to know it transmission is ongoing
Definition: uart_soft.c:92
UART_SOFT_TX_PIN0
#define UART_SOFT_TX_PIN0
pin for transmit signal for UART port 0
Definition: uart_soft.c:51
NVIC_EXTI_IRQ
#define NVIC_EXTI_IRQ(x)
get NVIC IRQ for external interrupt base on external interrupt/pin
Definition: global.h:156
soft_uart_tx_state::buffer_used
volatile uint8_t buffer_used
how much data is available
Definition: uart_soft.c:91
UART_SOFT_RX_PIN0
#define UART_SOFT_RX_PIN0
pin for receive signal for UART port 0
Definition: uart_soft.c:43
uart_soft_transmit
static void uart_soft_transmit(uint8_t uart)
start transmitting a byte from the buffer
Definition: uart_soft.c:269
uart_soft.h
library to control up to 4 independent receive and transmit software UART ports (API) ...
soft_uart_rx_state::buffer_i
volatile uint8_t buffer_i
index of current data to be read out
Definition: uart_soft.c:74
global.h
global definitions and methods (API)
GPIO
#define GPIO(x)
get GPIO based on GPIO identifier
Definition: global.h:103
soft_uart_rx_state::bit
volatile uint8_t bit
next UART frame bit to receive
Definition: uart_soft.c:71
soft_uart_rx_state::baudrate
uint32_t baudrate
UART receive baud rate.
Definition: uart_soft.c:69
uart_soft_putbyte_blocking
void uart_soft_putbyte_blocking(uint8_t uart, uint8_t byte)
transmit byte on UART port
Definition: uart_soft.c:303
RCC_TIM
#define RCC_TIM(x)
get RCC for timer based on TIM identifier
Definition: global.h:109
UART_SOFT_TX_PORT0
#define UART_SOFT_TX_PORT0
port for transmit signal for UART port 0
Definition: uart_soft.c:50
soft_uart_tx_state::port
uint32_t port
UART receive port.
Definition: uart_soft.c:83
uart_soft_getbyte
uint8_t uart_soft_getbyte(uint8_t uart)
get received byte from UART port
Definition: uart_soft.c:195
soft_uart_rx_state::lock
volatile bool lock
put lock when changing buffer_i or buffer_used
Definition: uart_soft.c:76
soft_uart_tx_state::bit
volatile uint8_t bit
next UART frame bit to transmit
Definition: uart_soft.c:87
soft_uart_rx_state::buffer_used
volatile uint8_t buffer_used
how much data is available
Definition: uart_soft.c:75
soft_uart_tx_state::pin
uint16_t pin
UART receive pin.
Definition: uart_soft.c:84
soft_uart_rx_state
UART receive state definition.
Definition: uart_soft.c:63
soft_uart_tx_state
UART transmit state definition.
Definition: uart_soft.c:82
soft_uart_tx_state::byte
volatile uint8_t byte
byte being transmitted
Definition: uart_soft.c:88
EXTI
#define EXTI(x)
get external interrupt based on pin identifier
Definition: global.h:154
UART_SOFT_TX_TIMER
#define UART_SOFT_TX_TIMER
timer peripheral for transmit signals
Definition: uart_soft.c:107
soft_uart_rx_state::byte
volatile uint8_t byte
byte being received
Definition: uart_soft.c:72
soft_uart_tx_state::buffer_i
volatile uint8_t buffer_i
index of current data to be read out
Definition: uart_soft.c:90
exti9_5_isr
void exti9_5_isr(void)
GPIO interrupt service routine to detect UART receive activity.
Definition: uart_soft.c:401
buffer
static uint8_t * buffer
input/output buffer for read/write commands/functions
Definition: onewire_master.c:67
soft_uart_rx_state::port
uint32_t port
UART receive port.
Definition: uart_soft.c:64
timer_interrupt
static const uint32_t timer_interrupt[4]
the interrupt enable for the compare units
Definition: uart_soft.c:112
timer_oc
static enum tim_oc_id timer_oc[4]
the output compares for the compare units
Definition: uart_soft.c:113
soft_uart_rx_state::state
volatile uint16_t state
GPIO state for receive pin.
Definition: uart_soft.c:70
soft_uart_rx_state::irq
uint32_t irq
UART receive interrupt request.
Definition: uart_soft.c:68
soft_uart_rx_state::buffer_byte
volatile uint8_t buffer_byte
to temporary store byte while locked
Definition: uart_soft.c:77
LENGTH
#define LENGTH(x)
get the length of an array
Definition: global.h:26
UART_SOFT_RX_TIMER
#define UART_SOFT_RX_TIMER
timer peripheral for receive signals
Definition: uart_soft.c:104
soft_uart_tx_state::buffer
volatile uint8_t buffer[UART_SOFT_BUFFER]
receive buffer
Definition: uart_soft.c:89
uart_soft_setup
bool uart_soft_setup(uint32_t *rx_baudrates, uint32_t *tx_baudrates)
setup software UART ports
Definition: uart_soft.c:115
soft_uart_rx_state::buffer
volatile uint8_t buffer[UART_SOFT_BUFFER]
receive buffer
Definition: uart_soft.c:73
TIM
#define TIM(x)
get TIM based on TIM identifier
Definition: global.h:107
soft_uart_rx_state::rcc
uint32_t rcc
UART receive port peripheral clock.
Definition: uart_soft.c:66
uart_soft_tx_states
static struct soft_uart_tx_state * uart_soft_tx_states[4]
states of UART transmit ports (up to 4)
Definition: uart_soft.c:96
UART_SOFT_BUFFER
#define UART_SOFT_BUFFER
buffer size for receive and transmit buffers
Definition: uart_soft.c:61
uart_soft_rx_states
static struct soft_uart_rx_state * uart_soft_rx_states[4]
states of UART receive ports (up to 4)
Definition: uart_soft.c:95
timer_flags
static const uint32_t timer_flags[4]
the interrupt flags for the compare units
Definition: uart_soft.c:111
soft_uart_rx_state::pin
uint16_t pin
UART receive pin.
Definition: uart_soft.c:65
uart_soft_receive_activity
static void uart_soft_receive_activity(void)
central function handling receive signal activity
Definition: uart_soft.c:341
uart_soft_received
volatile bool uart_soft_received[4]
if data has been received from UART port and is available to be read
Definition: uart_soft.c:98