add mqtt, decouple i2c and sensor

port/lwipopts.h

@@ -20,11 +20,9 @@
 #define MEM_SIZE (4 * 1024)
 
 // Pbuf options
-#define PBUF_POOL_SIZE 6
+#define PBUF_POOL_SIZE 16
 #define PBUF_POOL_BUFSIZE 590
 
-#define MEMP_NUM_PBUF 6  // default 16
-
 // TCP options
 #define LWIP_TCP 1
 #define TCP_MSS 536
@@ -34,6 +32,7 @@
 
 #define LWIP_UDP 1
 #define MEMP_NUM_UDP_PCB 3  // # of concurrent UDP "connections"
+#define MEMP_NUM_SYS_TIMEOUT 8
 #define LWIP_ICMP 1
 
 #define LWIP_DHCP 1
@@ -41,6 +40,10 @@
 #define LWIP_HTTPD_FS_SUPPORT 1
 #define HTTPD_USE_CUSTOM_FSDATA 1
 
+// MQTT
+#define LWIP_MQTT_CLIENT 1
+#define MQTT_OUTPUT_RINGBUF_SIZE 512
+
 #define LWIP_NETIF_HOSTNAME 1
 #define LWIP_NETIF_LINK_CALLBACK 1
 #define LWIP_NETIF_STATUS_CALLBACK 1