wifi: squash commit of wifi implementation

Squashed commit of the following:

commit 7684f6a159896d44ec7dc865aeb382ed674f5764
Author: A.M. Rowsell <amr@frzn.dev>
Date:   Wed Jun 24 02:53:46 2026 -0400

    wireless: these files also need to be present to build, oops.

commit 3b5760f4ffa6e0162fad54552a7274d3209334d8
Author: A.M. Rowsell <amr@frzn.dev>
Date:   Tue Jun 23 10:57:55 2026 -0400

    wifi: working setup with MQTT, plus averaging of readings

CMakeLists.txt

@@ -17,16 +17,20 @@ include(pico_sdk_import.cmake)
 if (PICO_SDK_VERSION_STRING VERSION_LESS "1.4.0")
   message(FATAL_ERROR "Raspberry Pi Pico SDK version 1.4.0 (or later) required. Your version is ${PICO_SDK_VERSION_STRING}")
 endif()
-
-project(ensaht C CXX ASM)
-
 # Initialise the Raspberry Pi Pico SDK
 pico_sdk_init()
 
+project(ensaht C CXX ASM)
+
 # Add executable. Default name is the project name, version 0.1
 
-add_executable(ensaht ensaht.c )
+add_executable(ensaht ensaht.c mqtt.c)
 
+# Add the standard include files to the build
+target_include_directories(ensaht PRIVATE
+  ${CMAKE_CURRENT_LIST_DIR}
+  ${CMAKE_CURRENT_LIST_DIR}/.. # for our common lwipopts or any other standard includes, if required
+)
 pico_set_program_name(ensaht "ensaht")
 pico_set_program_version(ensaht "0.1")
 pico_enable_stdio_usb(ensaht 1)
@@ -37,23 +41,19 @@ target_link_libraries(ensaht
         hardware_gpio
         hardware_divider
         pico_double
+        pico_cyw43_arch_lwip_threadsafe_background
+        pico_lwip_mqtt
+        pico_lwip_mbedtls
+        pico_mbedtls
         pico_stdlib)
-if (PICO_CYW43_SUPPORTED)
-    target_link_libraries(ensaht pico_cyw43_arch_none)
-endif()
-# Add the standard include files to the build
-target_include_directories(ensaht PRIVATE
-  ${CMAKE_CURRENT_LIST_DIR}
-  ${CMAKE_CURRENT_LIST_DIR}/.. # for our common lwipopts or any other standard includes, if required
-)
 
 pico_add_extra_outputs(ensaht)
 
 add_custom_target(flash
     COMMAND openocd
         -f interface/cmsis-dap.cfg
-        -f target/rp2350.cfg
+        -f target/rp2040.cfg
-        -c "adapter speed 5000"
+        -c "adapter speed 10000"
         -c "program ${CMAKE_CURRENT_BINARY_DIR}/ensaht.elf verify reset exit"
     DEPENDS ensaht
 )

ensaht.c

@@ -1,13 +1,16 @@
 #include "hardware/gpio.h"
 #include "hardware/i2c.h"
+#include "mqtt.h"
 #include "pico/cyw43_arch.h"
 #include "pico/stdlib.h"
 #include <boards/pico_w.h>
 #include <hardware/structs/io_bank0.h>
 #include <pico/binary_info/code.h>
 #include <pico/double.h>
+#include <pico/error.h>
 #include <stdio.h>
 
+// I2C device defines
 #define AHT_ADDR 0x38
 #define ENS_ADDR 0x53
 uint8_t AHT_MEASURE[3] = {0xAC, 0x33, 0x00};
@@ -22,6 +25,48 @@ uint8_t ENS_IDLE[2] = {0x10, 0x01};
 #define ENS_ECO2 0x24
 #define ENS_ETOH 0x26
 
+#define AVERAGES 16
+
+// MQTT and WiFi defines
+#define ADAFRUIT_IO_HOST "io.adafruit.com"
+#define ADAFRUIT_IO_USERNAME "ADAFRUIT_IO_USERNAME"
+#define ADAFRUIT_IO_PASSWORD "ADAFRUIT_IO_KEY"
+#define WIFI_SSID "Meosjin"
+#define WIFI_PASSWORD "WIFI_PASSWORD"
+#define MQTT_KEEP_ALIVE_SECONDS 60
+
+// MQTT Topics
+char temp_topic[] = "ADAFRUIT_IO_USERNAME/feeds/ensaht.temperature";
+char humi_topic[] = "ADAFRUIT_IO_USERNAME/feeds/ensaht.humidity";
+char aqi_topic[] = "ADAFRUIT_IO_USERNAME/feeds/ensaht.aqi";
+char tvoc_topic[] = "ADAFRUIT_IO_USERNAME/feeds/ensaht.tvoc";
+char etoh_topic[] = "ADAFRUIT_IO_USERNAME/feeds/ensaht.etoh";
+char eco2_topic[] = "ADAFRUIT_IO_USERNAME/feeds/ensaht.eco2";
+
+static void mqtt_connection_cb(mqtt_client_t *client, void *arg,
+                               mqtt_connection_status_t status) {
+  LWIP_UNUSED_ARG(client);
+  LWIP_UNUSED_ARG(arg);
+
+  printf("MQTT status: %d\n", status);
+}
+
+static double average_double(const double *samples, uint8_t count) {
+  double sum = 0.0;
+  for (uint8_t i = 0; i < count; i++) {
+    sum += samples[i];
+  }
+  return sum / count;
+}
+
+static uint16_t average_uint16(const uint16_t *samples, uint8_t count) {
+  uint32_t sum = 0;
+  for (uint8_t i = 0; i < count; i++) {
+    sum += samples[i];
+  }
+  return (uint16_t)((sum + count / 2) / count);
+}
+
 void getAHTData(double *t, double *h) {
   uint8_t result[6];
   uint32_t temperature, humidity;
@@ -54,7 +99,6 @@ uint8_t getENSData(double *t, double *h, uint8_t *AQI, uint16_t *TVOC,
                           (uint8_t)(RH & 0x00FF), (uint8_t)(RH >> 8)};
   uint8_t result[7], dataReg = ENS_AQI, valid;
   i2c_write_blocking(i2c_default, ENS_ADDR, inputData, 5, false);
-  activateENS();
   sleep_ms(100);
   i2c_write_blocking(i2c_default, ENS_ADDR, &dataReg, 1, true);
   i2c_read_blocking(i2c_default, ENS_ADDR, result, 7, false);
@@ -65,19 +109,62 @@ uint8_t getENSData(double *t, double *h, uint8_t *AQI, uint16_t *TVOC,
   dataReg = 0x20; // status register
   i2c_write_blocking(i2c_default, ENS_ADDR, &dataReg, 1, true);
   i2c_read_blocking(i2c_default, ENS_ADDR, result, 1, false);
-  printf("Status register is 0x%0X\n", result[0]);
   valid = (result[0] & ENS_STATUS_MASK) == 0
               ? 1
               : 0; // check if we are in warm-up or normal mode
-  // deactivateENS();
   return valid;
 }
-
 int main() {
-  uint16_t tvoc, eco2, etoh;
+  uint16_t tvoc, eco2, etoh, avg_tvoc, avg_eco2, avg_etoh;
   uint8_t aqi, validData;
-  double t, h;
+  double t, h, avg_t, avg_h;
+  uint16_t tvoc_avg[AVERAGES], eco2_avg[AVERAGES], etoh_avg[AVERAGES];
+  double t_avg[AVERAGES], h_avg[AVERAGES];
+  char payload[32];
+  // MQTT setup
+  ensaht_mqtt_t mqtt;
+  struct mqtt_connect_client_info_t mqtt_client_info = {
+      .client_id = ADAFRUIT_IO_USERNAME,
+      .client_user = ADAFRUIT_IO_USERNAME,
+      .client_pass = ADAFRUIT_IO_PASSWORD,
+      .keep_alive = MQTT_KEEP_ALIVE_SECONDS,
+  };
+  // setup stdio
   stdio_init_all();
+  // wifi chip initialization
+  if (cyw43_arch_init_with_country(CYW43_COUNTRY_CANADA)) {
+    printf("failed to initialise\n");
+    return 1;
+  }
+  cyw43_arch_enable_sta_mode();
+  int wifierr = 1;
+
+  wifierr = cyw43_arch_wifi_connect_timeout_ms(WIFI_SSID, WIFI_PASSWORD,
+                                               CYW43_AUTH_WPA2_AES_PSK, 30000);
+  if (wifierr) {
+    printf("failed to connect to Wi-Fi, reason %d\n", wifierr);
+    switch (wifierr) {
+    case PICO_ERROR_BADAUTH:
+      printf("Password incorrect.\n");
+      break;
+    case PICO_ERROR_TIMEOUT:
+      printf("Timeout ran out before connection.\n");
+      break;
+    case PICO_ERROR_CONNECT_FAILED:
+      printf("A damn generic error code.\n");
+      break;
+    default:
+      printf("Not a known error code.\n");
+      break;
+    }
+  }
+  ensaht_mqtt_init(&mqtt);
+  err_t mqtt_err =
+      ensaht_mqtt_connect(&mqtt, ADAFRUIT_IO_HOST, MQTT_PORT, &mqtt_client_info,
+                          mqtt_connection_cb, NULL);
+  if (mqtt_err != ERR_OK) {
+    printf("MQTT connect start failed: %d\n", mqtt_err);
+  }
   i2c_init(i2c_default, 100 * 1000); // start i2c at 100khz
   gpio_set_function(PICO_DEFAULT_I2C_SCL_PIN, GPIO_FUNC_I2C);
   gpio_set_function(PICO_DEFAULT_I2C_SDA_PIN, GPIO_FUNC_I2C);
@@ -86,16 +173,56 @@ int main() {
 
   bi_decl(bi_2pins_with_func(PICO_DEFAULT_I2C_SDA_PIN, PICO_DEFAULT_I2C_SCL_PIN,
                              GPIO_FUNC_I2C));
-
+  printf("\x1b[2J"); // clear screen
+  uint8_t i = 0;
+  uint8_t sample_count = 0;
+  activateENS();
   while (1) {
+    // cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, 1);
     getAHTData(&t, &h);
-    printf("Temperature %f Humidity %f\n", t, h);
+    t_avg[i] = t;
-    validData = getENSData(&t, &h, &aqi, &tvoc, &eco2, &etoh);
+    h_avg[i] = h;
-    if (!validData) {
+    if (sample_count < AVERAGES) {
-      printf("ENS Data not yet valid\n");
+      sample_count++;
     }
-    printf("AQI: %d TVOC: %d eCO2: %d EtOH: %d\n", aqi, tvoc, eco2, etoh);
+    avg_t = average_double(t_avg, sample_count);
-    sleep_ms(2000);
+    avg_h = average_double(h_avg, sample_count);
+    printf("\x1b[J\x1b[HTemperature %0.2f Humidity %0.2f\n", avg_t, avg_h);
+    validData = getENSData(&avg_t, &avg_h, &aqi, &tvoc, &eco2, &etoh);
+    tvoc_avg[i] = tvoc;
+    eco2_avg[i] = eco2;
+    etoh_avg[i] = etoh;
+    avg_tvoc = average_uint16(tvoc_avg, sample_count);
+    avg_eco2 = average_uint16(eco2_avg, sample_count);
+    avg_etoh = average_uint16(etoh_avg, sample_count);
+    if (!validData) {
+      printf("!! ");
+    }
+    printf("AQI: %d TVOC: %d eCO2: %d EtOH: %d\n", aqi, avg_tvoc, avg_eco2,
+           avg_etoh);
+    // cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, 0);
+    i++;
+    if (i == AVERAGES)
+      i = 0;
+    snprintf(payload, sizeof(payload), "%.2f", avg_t);
+    ensaht_mqtt_publish_client(&mqtt, temp_topic, payload, strlen(payload),
+                               NULL, NULL);
+    snprintf(payload, sizeof(payload), "%.2f", avg_h);
+    ensaht_mqtt_publish_client(&mqtt, humi_topic, payload, strlen(payload),
+                               NULL, NULL);
+    snprintf(payload, sizeof(payload), "%d", avg_tvoc);
+    ensaht_mqtt_publish_client(&mqtt, tvoc_topic, payload, strlen(payload),
+                               NULL, NULL);
+    snprintf(payload, sizeof(payload), "%d", avg_eco2);
+    ensaht_mqtt_publish_client(&mqtt, eco2_topic, payload, strlen(payload),
+                               NULL, NULL);
+    snprintf(payload, sizeof(payload), "%d", avg_etoh);
+    ensaht_mqtt_publish_client(&mqtt, etoh_topic, payload, strlen(payload),
+                               NULL, NULL);
+    snprintf(payload, sizeof(payload), "%d", aqi);
+    ensaht_mqtt_publish_client(&mqtt, aqi_topic, payload, strlen(payload), NULL,
+                               NULL);
+    sleep_ms(30000);
   }
 
   return 0;

lwipopts.h

@@ -0,0 +1,33 @@
+#ifndef _LWIPOPTS_H
+#define _LWIPOPTS_H
+
+// Generally you would define your own explicit list of lwIP options
+// (see https://www.nongnu.org/lwip/2_1_x/group__lwip__opts.html)
+//
+// This example uses a common include to avoid repetition
+#include "lwipopts_examples_common.h"
+
+/* TCP WND must be at least 16 kb to match TLS record size
+   or you will get a warning "altcp_tls: TCP_WND is smaller than the RX decrypion buffer, connection RX might stall!" */
+#undef TCP_WND
+#define TCP_WND  16384
+
+#undef MEMP_NUM_SYS_TIMEOUT
+#define MEMP_NUM_SYS_TIMEOUT (LWIP_NUM_SYS_TIMEOUT_INTERNAL + 8)
+
+#undef MQTT_REQ_MAX_IN_FLIGHT
+#define MQTT_REQ_MAX_IN_FLIGHT 8
+
+#define LWIP_ALTCP 1
+
+// If you don't want to use TLS (just a http request) you can avoid linking to mbedtls and remove the following
+#define LWIP_ALTCP_TLS           1
+#define LWIP_ALTCP_TLS_MBEDTLS   1
+
+// Note bug in lwip with LWIP_ALTCP and LWIP_DEBUG
+// https://savannah.nongnu.org/bugs/index.php?62159
+//#define LWIP_DEBUG 1
+#undef LWIP_DEBUG
+#define ALTCP_MBEDTLS_DEBUG  LWIP_DBG_ON
+
+#endif

lwipopts_examples_common.h

@@ -0,0 +1,92 @@
+#ifndef _LWIPOPTS_EXAMPLE_COMMONH_H
+#define _LWIPOPTS_EXAMPLE_COMMONH_H
+
+
+// Common settings used in most of the pico_w examples
+// (see https://www.nongnu.org/lwip/2_1_x/group__lwip__opts.html for details)
+
+// allow override in some examples
+#ifndef NO_SYS
+#define NO_SYS                      1
+#endif
+// allow override in some examples
+#ifndef LWIP_SOCKET
+#define LWIP_SOCKET                 0
+#endif
+#if PICO_CYW43_ARCH_POLL
+#define MEM_LIBC_MALLOC             1
+#else
+// MEM_LIBC_MALLOC is incompatible with non polling versions
+#define MEM_LIBC_MALLOC             0
+#endif
+#define MEM_ALIGNMENT               4
+#ifndef MEM_SIZE
+#define MEM_SIZE                    4000
+#endif
+#define MEMP_NUM_TCP_SEG            32
+#define MEMP_NUM_ARP_QUEUE          10
+#define PBUF_POOL_SIZE              24
+#define LWIP_ARP                    1
+#define LWIP_ETHERNET               1
+#define LWIP_ICMP                   1
+#define LWIP_RAW                    1
+#define TCP_WND                     (8 * TCP_MSS)
+#define TCP_MSS                     1460
+#define TCP_SND_BUF                 (8 * TCP_MSS)
+#define TCP_SND_QUEUELEN            ((4 * (TCP_SND_BUF) + (TCP_MSS - 1)) / (TCP_MSS))
+#define LWIP_NETIF_STATUS_CALLBACK  1
+#define LWIP_NETIF_LINK_CALLBACK    1
+#define LWIP_NETIF_HOSTNAME         1
+#define LWIP_NETCONN                0
+#define MEM_STATS                   0
+#define SYS_STATS                   0
+#define MEMP_STATS                  0
+#define LINK_STATS                  0
+// #define ETH_PAD_SIZE                2
+#define LWIP_CHKSUM_ALGORITHM       3
+#define LWIP_DHCP                   1
+#define LWIP_IPV4                   1
+#define LWIP_TCP                    1
+#define LWIP_UDP                    1
+#define LWIP_DNS                    1
+#define LWIP_TCP_KEEPALIVE          1
+#define LWIP_NETIF_TX_SINGLE_PBUF   1
+#define DHCP_DOES_ARP_CHECK         0
+#define LWIP_DHCP_DOES_ACD_CHECK    0
+
+#ifndef NDEBUG
+#define LWIP_DEBUG                  1
+#define LWIP_STATS                  1
+#define LWIP_STATS_DISPLAY          1
+#endif
+
+#define ETHARP_DEBUG                LWIP_DBG_OFF
+#define NETIF_DEBUG                 LWIP_DBG_OFF
+#define PBUF_DEBUG                  LWIP_DBG_OFF
+#define API_LIB_DEBUG               LWIP_DBG_OFF
+#define API_MSG_DEBUG               LWIP_DBG_OFF
+#define SOCKETS_DEBUG               LWIP_DBG_OFF
+#define ICMP_DEBUG                  LWIP_DBG_OFF
+#define INET_DEBUG                  LWIP_DBG_OFF
+#define IP_DEBUG                    LWIP_DBG_OFF
+#define IP_REASS_DEBUG              LWIP_DBG_OFF
+#define RAW_DEBUG                   LWIP_DBG_OFF
+#define MEM_DEBUG                   LWIP_DBG_OFF
+#define MEMP_DEBUG                  LWIP_DBG_OFF
+#define SYS_DEBUG                   LWIP_DBG_OFF
+#define TCP_DEBUG                   LWIP_DBG_OFF
+#define TCP_INPUT_DEBUG             LWIP_DBG_OFF
+#define TCP_OUTPUT_DEBUG            LWIP_DBG_OFF
+#define TCP_RTO_DEBUG               LWIP_DBG_OFF
+#define TCP_CWND_DEBUG              LWIP_DBG_OFF
+#define TCP_WND_DEBUG               LWIP_DBG_OFF
+#define TCP_FR_DEBUG                LWIP_DBG_OFF
+#define TCP_QLEN_DEBUG              LWIP_DBG_OFF
+#define TCP_RST_DEBUG               LWIP_DBG_OFF
+#define UDP_DEBUG                   LWIP_DBG_OFF
+#define TCPIP_DEBUG                 LWIP_DBG_OFF
+#define PPP_DEBUG                   LWIP_DBG_OFF
+#define SLIP_DEBUG                  LWIP_DBG_OFF
+#define DHCP_DEBUG                  LWIP_DBG_OFF
+
+#endif /* __LWIPOPTS_H__ */

mbedtls_config.h

@@ -0,0 +1,6 @@
+#ifndef MBEDTLS_CONFIG_TLS_CLIENT_H
+#define MBEDTLS_CONFIG_TLS_CLIENT_H
+
+#include "mbedtls_config_examples_common.h"
+
+#endif

mbedtls_config_examples_common.h

@@ -0,0 +1,75 @@
+#ifndef MBEDTLS_CONFIG_EXAMPLES_COMMON_H
+#define MBEDTLS_CONFIG_EXAMPLES_COMMON_H
+
+/* Workaround for some mbedtls source files using INT_MAX without including limits.h */
+#include <limits.h>
+
+#define MBEDTLS_NO_PLATFORM_ENTROPY
+#define MBEDTLS_ENTROPY_HARDWARE_ALT
+
+#define MBEDTLS_SSL_OUT_CONTENT_LEN 2048
+
+#define MBEDTLS_ALLOW_PRIVATE_ACCESS
+#define MBEDTLS_HAVE_TIME
+#define MBEDTLS_PLATFORM_MS_TIME_ALT
+
+#define MBEDTLS_CIPHER_MODE_CBC
+#define MBEDTLS_ECP_DP_SECP192R1_ENABLED
+#define MBEDTLS_ECP_DP_SECP224R1_ENABLED
+#define MBEDTLS_ECP_DP_SECP256R1_ENABLED
+#define MBEDTLS_ECP_DP_SECP384R1_ENABLED
+#define MBEDTLS_ECP_DP_SECP521R1_ENABLED
+#define MBEDTLS_ECP_DP_SECP192K1_ENABLED
+#define MBEDTLS_ECP_DP_SECP224K1_ENABLED
+#define MBEDTLS_ECP_DP_SECP256K1_ENABLED
+#define MBEDTLS_ECP_DP_BP256R1_ENABLED
+#define MBEDTLS_ECP_DP_BP384R1_ENABLED
+#define MBEDTLS_ECP_DP_BP512R1_ENABLED
+#define MBEDTLS_ECP_DP_CURVE25519_ENABLED
+#define MBEDTLS_KEY_EXCHANGE_RSA_ENABLED
+#define MBEDTLS_PKCS1_V15
+#define MBEDTLS_SHA256_SMALLER
+#define MBEDTLS_SSL_SERVER_NAME_INDICATION
+#define MBEDTLS_AES_C
+#define MBEDTLS_ASN1_PARSE_C
+#define MBEDTLS_BIGNUM_C
+#define MBEDTLS_CIPHER_C
+#define MBEDTLS_CTR_DRBG_C
+#define MBEDTLS_ENTROPY_C
+#define MBEDTLS_ERROR_C
+#define MBEDTLS_MD_C
+#define MBEDTLS_MD5_C
+#define MBEDTLS_OID_C
+#define MBEDTLS_PKCS5_C
+#define MBEDTLS_PK_C
+#define MBEDTLS_PK_PARSE_C
+#define MBEDTLS_PLATFORM_C
+#define MBEDTLS_RSA_C
+#define MBEDTLS_SHA1_C
+#define MBEDTLS_SHA224_C
+#define MBEDTLS_SHA256_C
+#define MBEDTLS_SHA512_C
+#define MBEDTLS_SSL_CLI_C
+#define MBEDTLS_SSL_SRV_C
+#define MBEDTLS_SSL_TLS_C
+#define MBEDTLS_X509_CRT_PARSE_C
+#define MBEDTLS_X509_USE_C
+#define MBEDTLS_AES_FEWER_TABLES
+
+/* TLS 1.2 */
+#define MBEDTLS_SSL_PROTO_TLS1_2
+#define MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED
+#define MBEDTLS_GCM_C
+#define MBEDTLS_ECDH_C
+#define MBEDTLS_ECP_C
+#define MBEDTLS_ECDSA_C
+#define MBEDTLS_ASN1_WRITE_C
+
+// The following is needed to parse a certificate
+#define MBEDTLS_PEM_PARSE_C
+#define MBEDTLS_BASE64_C
+
+// The following significantly speeds up mbedtls due to NIST optimizations.
+#define MBEDTLS_ECP_NIST_OPTIM
+
+#endif

mqtt.c

@@ -0,0 +1,157 @@
+#include "mqtt.h"
+
+#include "lwip/altcp.h"
+#include "lwip/altcp_tls.h"
+#include "lwip/apps/mqtt_priv.h"
+#include "lwip/dns.h"
+#include "pico/cyw43_arch.h"
+#include <string.h>
+
+static void ensaht_mqtt_default_connect_cb(mqtt_client_t *client, void *arg,
+                                           mqtt_connection_status_t status) {
+  LWIP_UNUSED_ARG(client);
+  LWIP_UNUSED_ARG(arg);
+  LWIP_UNUSED_ARG(status);
+}
+
+static err_t ensaht_mqtt_start(ensaht_mqtt_t *mqtt) {
+  err_t err;
+
+  if (mqtt->client == NULL) {
+    mqtt->client = mqtt_client_new();
+    if (mqtt->client == NULL) {
+      return ERR_MEM;
+    }
+  }
+
+  err = mqtt_client_connect(mqtt->client, &mqtt->server_addr, mqtt->port,
+                            mqtt->connect_cb, mqtt->connect_arg,
+                            &mqtt->client_info);
+#if LWIP_ALTCP && LWIP_ALTCP_TLS
+  if (err == ERR_OK && mqtt->client_info.tls_config != NULL) {
+    mbedtls_ssl_set_hostname(altcp_tls_context(mqtt->client->conn),
+                             mqtt->hostname);
+  }
+#endif
+
+  return err;
+}
+
+static void ensaht_mqtt_dns_found(const char *hostname, const ip_addr_t *ipaddr,
+                                  void *arg) {
+  ensaht_mqtt_t *mqtt = (ensaht_mqtt_t *)arg;
+  LWIP_UNUSED_ARG(hostname);
+
+  if (ipaddr == NULL) {
+    if (mqtt->connect_cb != NULL) {
+      mqtt->connect_cb(mqtt->client, mqtt->connect_arg, MQTT_CONNECT_TIMEOUT);
+    }
+    return;
+  }
+
+  mqtt->server_addr = *ipaddr;
+  cyw43_arch_lwip_begin();
+  err_t err = ensaht_mqtt_start(mqtt);
+  cyw43_arch_lwip_end();
+
+  if (err != ERR_OK && mqtt->connect_cb != NULL) {
+    mqtt->connect_cb(mqtt->client, mqtt->connect_arg,
+                     MQTT_CONNECT_DISCONNECTED);
+  }
+}
+
+void ensaht_mqtt_init(ensaht_mqtt_t *mqtt) { memset(mqtt, 0, sizeof(*mqtt)); }
+
+err_t ensaht_mqtt_connect(ensaht_mqtt_t *mqtt, const char *hostname, u16_t port,
+                          const struct mqtt_connect_client_info_t *client_info,
+                          mqtt_connection_cb_t cb, void *arg) {
+  err_t err;
+
+  if (mqtt == NULL || hostname == NULL || client_info == NULL ||
+      client_info->client_id == NULL) {
+    return ERR_ARG;
+  }
+
+  mqtt->hostname = hostname;
+  mqtt->port = port != 0 ? port : MQTT_PORT;
+  mqtt->client_info = *client_info;
+  mqtt->connect_cb = cb != NULL ? cb : ensaht_mqtt_default_connect_cb;
+  mqtt->connect_arg = arg;
+
+  cyw43_arch_lwip_begin();
+  err = dns_gethostbyname(hostname, &mqtt->server_addr, ensaht_mqtt_dns_found,
+                          mqtt);
+  if (err == ERR_OK) {
+    err = ensaht_mqtt_start(mqtt);
+  }
+  cyw43_arch_lwip_end();
+
+  return err == ERR_INPROGRESS ? ERR_OK : err;
+}
+
+void ensaht_mqtt_disconnect(ensaht_mqtt_t *mqtt) {
+  if (mqtt == NULL || mqtt->client == NULL) {
+    return;
+  }
+
+  cyw43_arch_lwip_begin();
+  mqtt_disconnect(mqtt->client);
+  cyw43_arch_lwip_end();
+}
+
+err_t ensaht_mqtt_publish(mqtt_client_t *client, const char *topic,
+                          const void *payload, u16_t payload_length,
+                          mqtt_request_cb_t cb, void *arg) {
+  return mqtt_publish(client, topic, payload, payload_length, 1, 0, cb, arg);
+}
+
+err_t ensaht_mqtt_publish_client(ensaht_mqtt_t *mqtt, const char *topic,
+                                 const void *payload, u16_t payload_length,
+                                 mqtt_request_cb_t cb, void *arg) {
+  err_t err;
+
+  if (mqtt == NULL || mqtt->client == NULL) {
+    return ERR_CONN;
+  }
+
+  cyw43_arch_lwip_begin();
+  err = ensaht_mqtt_publish(mqtt->client, topic, payload, payload_length, cb,
+                            arg);
+  cyw43_arch_lwip_end();
+
+  return err;
+}
+
+err_t ensaht_mqtt_pingreq(mqtt_client_t *client) {
+  static const u8_t pingreq[] = {0xC0, 0x00};
+  err_t err;
+
+  LWIP_ASSERT_CORE_LOCKED();
+  if (client == NULL || client->conn == NULL ||
+      !mqtt_client_is_connected(client)) {
+    return ERR_CONN;
+  }
+
+  err =
+      altcp_write(client->conn, pingreq, sizeof(pingreq), TCP_WRITE_FLAG_COPY);
+  if (err == ERR_OK) {
+    client->cyclic_tick = 0;
+    err = altcp_output(client->conn);
+  }
+
+  return err;
+}
+
+err_t ensaht_mqtt_pingreq_client(ensaht_mqtt_t *mqtt) {
+  err_t err;
+
+  if (mqtt == NULL || mqtt->client == NULL) {
+    return ERR_CONN;
+  }
+
+  cyw43_arch_lwip_begin();
+  err = ensaht_mqtt_pingreq(mqtt->client);
+  cyw43_arch_lwip_end();
+
+  return err;
+}

mqtt.h

@@ -0,0 +1,31 @@
+#ifndef ENSAHT_MQTT_H
+#define ENSAHT_MQTT_H
+
+#include "lwip/apps/mqtt.h"
+
+typedef struct {
+  mqtt_client_t *client;
+  ip_addr_t server_addr;
+  const char *hostname;
+  u16_t port;
+  struct mqtt_connect_client_info_t client_info;
+  mqtt_connection_cb_t connect_cb;
+  void *connect_arg;
+} ensaht_mqtt_t;
+
+void ensaht_mqtt_init(ensaht_mqtt_t *mqtt);
+err_t ensaht_mqtt_connect(ensaht_mqtt_t *mqtt, const char *hostname, u16_t port,
+                          const struct mqtt_connect_client_info_t *client_info,
+                          mqtt_connection_cb_t cb, void *arg);
+void ensaht_mqtt_disconnect(ensaht_mqtt_t *mqtt);
+
+err_t ensaht_mqtt_publish(mqtt_client_t *client, const char *topic,
+                          const void *payload, u16_t payload_length,
+                          mqtt_request_cb_t cb, void *arg);
+err_t ensaht_mqtt_publish_client(ensaht_mqtt_t *mqtt, const char *topic,
+                                 const void *payload, u16_t payload_length,
+                                 mqtt_request_cb_t cb, void *arg);
+err_t ensaht_mqtt_pingreq(mqtt_client_t *client);
+err_t ensaht_mqtt_pingreq_client(ensaht_mqtt_t *mqtt);
+
+#endif