diff --git a/lib/radio_esp8266.c b/lib/radio_esp8266.c
new file mode 100644
index 0000000..fec5f0a
--- /dev/null
+++ b/lib/radio_esp8266.c
@@ -0,0 +1,141 @@
+/* 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 .
+ *
+ */
+/** library to send data using ESP8266 WiFi SoC (code)
+ * @file radio_esp8266.c
+ * @author King Kévin
+ * @date 2016
+ * @note peripherals used: USART @ref radio_esp8266_usart
+ */
+
+/* standard libraries */
+#include // standard integer types
+#include // general utilities
+#include // string and memory 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 2 /**< USART peripheral */
+/** @} */
+
+/* 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;
+
+void radio_esp8266_setup(void)
+{
+ /* enable USART I/O peripheral */
+ rcc_periph_clock_enable(RCC_AFIO); // enable pin alternate function (USART)
+ rcc_periph_clock_enable(USART_PORT_RCC(RADIO_ESP8266_USART)); // enable clock for USART port peripheral
+ rcc_periph_clock_enable(USART_RCC(RADIO_ESP8266_USART)); // enable clock for USART peripheral
+ gpio_set_mode(USART_PORT(RADIO_ESP8266_USART), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, USART_PIN_TX(RADIO_ESP8266_USART)); // setup GPIO pin USART transmit
+ gpio_set_mode(USART_PORT(RADIO_ESP8266_USART), GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN, USART_PIN_RX(RADIO_ESP8266_USART)); // setup GPIO pin USART receive
+ gpio_set(USART_PORT(RADIO_ESP8266_USART), USART_PIN_RX(RADIO_ESP8266_USART)); // pull up to avoid noise when not connected
+
+ /* setup USART parameters for ESP8266 AT firmware */
+ 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 USART interrupt
+ usart_enable_rx_interrupt(USART(RADIO_ESP8266_USART)); // enable receive interrupt
+ usart_enable(USART(RADIO_ESP8266_USART)); // enable USART
+
+ /* reset buffer states */
+ rx_used = 0;
+ tx_used = 0;
+ radio_esp8266_activity = false;
+ radio_esp8266_success = false;
+
+ radio_esp8266_send((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_send((uint8_t*)"AT+RST\r\n",8); // reset module
+ while (!radio_esp8266_activity || !radio_esp8266_success) { // wait for response
+ __WFI(); // sleep until something happened
+ }
+ radio_esp8266_send((uint8_t*)"ATE0\r\n",6); // disable echoing
+ while (!radio_esp8266_activity || !radio_esp8266_success) { // wait for response
+ __WFI(); // sleep until something happened
+ }
+ while(rx_used<13 || !memmem((char*)rx_buffer, rx_used, "WIFI GOT IP\r\n", 13)) { // wait to have IP
+ __WFI(); // sleep until something happened
+ }
+}
+
+void radio_esp8266_send(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(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 I'm fucked (AT commands are hard to handle perfectly)
+ // ideally memmem would not be done in ISR (takes quite long)
+ if (rx_used>=4 && memmem((char*)rx_buffer, rx_used, "OK\r\n", 4)) { // OK received
+ radio_esp8266_activity = true; // response received
+ radio_esp8266_success = true; // command succeeded
+ rx_used = 0; // reset buffer
+ } else if (rx_used>=7 && memmem((char*)rx_buffer, rx_used, "ERROR\r\n", 7)) { // ERROR received
+ radio_esp8266_activity = true; // response received
+ radio_esp8266_success = false; // command failed
+ rx_used = 0; // reset buffer
+ }
+ }
+}
diff --git a/lib/radio_esp8266.h b/lib/radio_esp8266.h
new file mode 100644
index 0000000..7842632
--- /dev/null
+++ b/lib/radio_esp8266.h
@@ -0,0 +1,47 @@
+/* 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 .
+ *
+ */
+/** library to send data using ESP8266 WiFi SoC (API)
+ * @file radio_esp8266.h
+ * @author King Kévin
+ * @date 2016
+ * @note peripherals used: USART @ref radio_esp8266_usart
+ */
+#pragma once
+
+/** a response has been returned by the radio */
+extern volatile bool radio_esp8266_activity;
+/** the last command has succeeded */
+extern volatile bool radio_esp8266_success;
+
+/** setup peripherals to communicate with radio
+ * @note this is blocking to ensure we are connected to the WiFi network
+ */
+void radio_esp8266_setup(void);
+/** establish TCP connection
+ * @param[in] host host to connect to
+ * @param[in] port TCP port to connect to
+ * @note wait for activity to get success status
+ */
+void radio_esp8266_tcp_open(char* host, uint32_t port);
+/** send data (requires established connection)
+ * @param[in] data data to send
+ * @param[in] length size of data to send
+ * @note wait for activity to get success status
+ */
+void radio_esp8266_send(uint8_t* data, uint8_t length);
+/** close established connection
+ * @note wait for activity to get success status
+ */
+void radio_esp8266_close(void);