/** library to send data using ESP8266 WiFi SoC (code) * @file * @author King Kévin * @copyright SPDX-License-Identifier: GPL-3.0-or-later * @date 2016-2022 * @note peripherals used: USART @ref radio_esp8266_usart */ /* standard libraries */ #include // standard integer types #include // general utilities #include // string and memory utilities #include // string utilities /* STM32 (including CM3) libraries */ #include // real-time control clock library #include // general purpose input output library #include // universal synchronous asynchronous receiver transmitter library #include // interrupt handler #include // Cortex M3 utilities #include "radio_esp8266.h" // radio header and definitions #include "global.h" // common methods /** @defgroup radio_esp8266_usart USART peripheral used for communication with radio * @{ */ #define RADIO_ESP8266_USART 1 /**< USART peripheral */ #define RADIO_ESP8266_TX PA9 /**< pin used for USART TX */ #define RADIO_ESP8266_RX PA10 /**< pin used for USART RX */ #define RADIO_ESP8266_AF GPIO_AF7 /**< alternate function for UART pins */ /** @} */ /* input and output buffers and used memory */ static uint8_t rx_buffer[24] = {0}; /**< buffer for received data (we only expect AT responses) */ static volatile uint16_t rx_used = 0; /**< number of byte in receive buffer */ static uint8_t tx_buffer[256] = {0}; /**< buffer for data to transmit */ static volatile uint16_t tx_used = 0; /**< number of bytes used in transmit buffer */ volatile bool radio_esp8266_activity = false; volatile bool radio_esp8266_success = false; /** transmit data to radio * @param[in] data data to transmit * @param[in] length length of data to transmit */ static void radio_esp8266_transmit(uint8_t* data, uint8_t length) { while (tx_used || !usart_get_flag(USART(RADIO_ESP8266_USART), USART_SR_TXE)) { // wait until ongoing transmission completed usart_enable_tx_interrupt(USART(RADIO_ESP8266_USART)); // enable transmit interrupt __WFI(); // sleep until something happened } usart_disable_tx_interrupt(USART(RADIO_ESP8266_USART)); // ensure transmit interrupt is disable to prevent index corruption (the ISR should already have done it) radio_esp8266_activity = false; // reset status because of new activity for (tx_used = 0; tx_used < length && tx_used < LENGTH(tx_buffer); tx_used++) { // copy data tx_buffer[tx_used] = data[length - 1 - tx_used]; // put character in buffer (in reverse order) } if (tx_used) { usart_enable_tx_interrupt(USART(RADIO_ESP8266_USART)); // enable interrupt to send bytes } } void radio_esp8266_setup(void) { // configure pins rcc_periph_clock_enable(GPIO_RCC(RADIO_ESP8266_TX)); // enable clock for USART TX pin port peripheral gpio_mode_setup(GPIO_PORT(RADIO_ESP8266_TX), GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO_PIN(RADIO_ESP8266_TX)); // set TX pin to alternate function gpio_set_output_options(GPIO_PORT(RADIO_ESP8266_TX), GPIO_OTYPE_PP, GPIO_OSPEED_25MHZ, GPIO_PIN(RADIO_ESP8266_TX)); // set TX pin output as push-pull gpio_set_af(GPIO_PORT(RADIO_ESP8266_TX), RADIO_ESP8266_AF, GPIO_PIN(RADIO_ESP8266_TX)); // set alternate function to USART rcc_periph_clock_enable(GPIO_RCC(RADIO_ESP8266_RX)); // enable clock for USART RX pin port peripheral gpio_mode_setup(GPIO_PORT(RADIO_ESP8266_RX), GPIO_MODE_AF, GPIO_PUPD_PULLUP, GPIO_PIN(RADIO_ESP8266_RX)); // set GPIO to alternate function, with pull up to avoid noise in case it is not connected gpio_set_af(GPIO_PORT(RADIO_ESP8266_RX), RADIO_ESP8266_AF, GPIO_PIN(RADIO_ESP8266_RX)); // set alternate function to USART // configure USART for ESP8266 AT firmware rcc_periph_clock_enable(RCC_USART(RADIO_ESP8266_USART)); // enable clock for USART peripheral rcc_periph_reset_pulse(RST_USART(RADIO_ESP8266_USART)); // reset peripheral usart_set_baudrate(USART(RADIO_ESP8266_USART), 115200); // AT firmware 0.51 (SDK 1.5.0) uses 115200 bps usart_set_databits(USART(RADIO_ESP8266_USART), 8); usart_set_stopbits(USART(RADIO_ESP8266_USART), USART_STOPBITS_1); usart_set_mode(USART(RADIO_ESP8266_USART), USART_MODE_TX_RX); usart_set_parity(USART(RADIO_ESP8266_USART), USART_PARITY_NONE); usart_set_flow_control(USART(RADIO_ESP8266_USART), USART_FLOWCONTROL_NONE); nvic_enable_irq(USART_IRQ(RADIO_ESP8266_USART)); // enable the UART interrupt usart_enable_rx_interrupt(USART(RADIO_ESP8266_USART)); // enable receive interrupt usart_enable(USART(RADIO_ESP8266_USART)); // enable UART /* reset buffer states */ rx_used = 0; tx_used = 0; radio_esp8266_activity = false; radio_esp8266_success = false; radio_esp8266_transmit((uint8_t*)"AT\r\n", 4); // verify if module is present while (!radio_esp8266_activity || !radio_esp8266_success) { // wait for response __WFI(); // sleep until something happened } radio_esp8266_transmit((uint8_t*)"AT+RST\r\n", 8); // reset module while (!radio_esp8266_activity || !radio_esp8266_success) { // wait for response __WFI(); // sleep until something happened } while(rx_used < 13 || memcmp((char*)&rx_buffer[rx_used - 13], "WIFI GOT IP\r\n", 13) != 0) { // wait to have IP __WFI(); // sleep until something happened } radio_esp8266_transmit((uint8_t*)"ATE0\r\n", 6); // disable echoing while (!radio_esp8266_activity || !radio_esp8266_success) { // wait for response __WFI(); // sleep until something happened } } void radio_esp8266_tcp_open(char* host, uint16_t port) { char command[256] = {0}; // string to create command int length = snprintf(command, LENGTH(command), "AT+CIPSTART=\"TCP\",\"%s\",%u\r\n", host, port); // create AT command to establish a TCP connection if (length > 0) { radio_esp8266_transmit((uint8_t*)command, length); } } void radio_esp8266_send(uint8_t* data, uint8_t length) { char command[16 + 1] = {0}; // string to create command int command_length = snprintf(command, LENGTH(command), "AT+CIPSEND=%u\r\n", length); // create AT command to send data if (command_length > 0) { radio_esp8266_transmit((uint8_t*)command, command_length); // transmit AT command while (!radio_esp8266_activity || !radio_esp8266_success) { // wait for response __WFI(); // sleep until something happened } if (!radio_esp8266_success) { // send AT command did not succeed return; // don't transmit data } radio_esp8266_transmit(data, length); // transmit data } } void radio_esp8266_close(void) { radio_esp8266_transmit((uint8_t*)"AT+CIPCLOSE\r\n", 13); // send AT command to close established connection } /** USART interrupt service routine called when data has been transmitted or received */ void USART_ISR(RADIO_ESP8266_USART)(void) { if (usart_get_flag(USART(RADIO_ESP8266_USART), USART_SR_TXE)) { // data has been transmitted if (tx_used) { // there is still data in the buffer to transmit usart_send(USART(RADIO_ESP8266_USART), tx_buffer[tx_used - 1]); // put data in transmit register tx_used--; // update used size } else { // no data in the buffer to transmit usart_disable_tx_interrupt(USART(RADIO_ESP8266_USART)); // disable transmit interrupt } } if (usart_get_flag(USART(RADIO_ESP8266_USART), USART_SR_RXNE)) { // data has been received while (rx_used >= LENGTH(rx_buffer)) { // if buffer is full memmove(rx_buffer, &rx_buffer[1], LENGTH(rx_buffer) - 1); // drop old data to make space (ring buffer are more efficient but harder to handle) rx_used--; // update used buffer information } rx_buffer[rx_used++] = usart_recv(USART(RADIO_ESP8266_USART)); // put character in buffer // if the used send a packet with these strings during the commands detection the AT command response will break (AT commands are hard to handle perfectly) if (rx_used >= 4 && memcmp((char*)&rx_buffer[rx_used - 4], "OK\r\n", 4) == 0) { // OK received radio_esp8266_activity = true; // response received radio_esp8266_success = true; // command succeeded rx_used = 0; // reset buffer } else if (rx_used >= 7 && memcmp((char*)&rx_buffer[rx_used - 7], "ERROR\r\n", 7) == 0) { // ERROR received radio_esp8266_activity = true; // response received radio_esp8266_success = false; // command failed rx_used = 0; // reset buffer } } }