diff --git a/README.md b/README.md
index 79634f3a..9dc8660d 100644
--- a/README.md
+++ b/README.md
@@ -50,6 +50,9 @@ LoLin32lite + [LoraNode32-Lite shield](https://github.com/hallard/LoLin32-Lite-L
 - Generic ESP32
 
 Depending on board hardware following features are supported:
+- LoRaWAN communication, supporting various payload formats (see enclosed .js converters)
+- MQTT communication via TCP/IP and Ethernet interface (note: payload transmitted over MQTT will be base64 encoded)
+- SPI serial communication to a local host
 - LED (shows power & status)
 - OLED Display (shows detailed status)
 - RGB LED (shows colorized status)
@@ -62,7 +65,6 @@ Depending on board hardware following features are supported:
 - Switch external power / battery
 - LED Matrix display (similar to [this 64x16 model](https://www.instructables.com/id/64x16-RED-LED-Marquee/), can be ordered on [Aliexpress](https://www.aliexpress.com/item/P3-75-dot-matrix-led-module-3-75mm-high-clear-top1-for-text-display-304-60mm/32616683948.html))
 - SD-card (see section SD-card here) for logging pax data
-- Ethernet interface for MQTT communication via TCP/IP
 
 Target platform must be selected in `platformio.ini`.<br>
 Hardware dependent settings (pinout etc.) are stored in board files in /hal directory. If you want to use a ESP32 board which is not yet supported, use hal file generic.h and tailor pin mappings to your needs. Pull requests for new boards welcome.<br>
diff --git a/include/mqttclient.h b/include/mqttclient.h
index a4fe4ac1..1c797a01 100644
--- a/include/mqttclient.h
+++ b/include/mqttclient.h
@@ -5,6 +5,7 @@
 #include "rcommand.h"
 #include <MQTT.h>
 #include <ETH.h>
+#include <mbedtls/base64.h>
 
 #ifndef MQTT_CLIENTNAME
 #define MQTT_CLIENTNAME clientId
@@ -17,8 +18,7 @@ uint32_t mqtt_queuewaiting(void);
 void mqtt_queuereset(void);
 void mqtt_client_task(void *param);
 int mqtt_connect(const char *my_host, const uint16_t my_port);
-void mqtt_callback(MQTTClient *client, char topic[], char payload[],
-                   int length);
+void mqtt_callback(MQTTClient *client, char *topic, char *payload, int length);
 void NetworkEvent(WiFiEvent_t event);
 esp_err_t mqtt_init(void);
 void mqtt_deinit(void);
diff --git a/include/reset.h b/include/reset.h
index af9d6c50..ddf3dfcb 100644
--- a/include/reset.h
+++ b/include/reset.h
@@ -11,7 +11,8 @@
 
 void do_reset(bool warmstart);
 void do_after_reset(void);
-void enter_deepsleep(const uint64_t wakeup_sec, const gpio_num_t wakeup_gpio);
+void enter_deepsleep(const uint64_t wakeup_sec = 60,
+                     const gpio_num_t wakeup_gpio = GPIO_NUM_MAX);
 unsigned long long uptime(void);
 
 #endif // _RESET_H
\ No newline at end of file
diff --git a/platformio_orig.ini b/platformio_orig.ini
index 27e0e688..a6cf1ac7 100644
--- a/platformio_orig.ini
+++ b/platformio_orig.ini
@@ -47,7 +47,7 @@ description = Paxcounter is a device for metering passenger flows in realtime. I
 
 [common]
 ; for release_version use max. 10 chars total, use any decimal format like "a.b.c"
-release_version = 2.1.0
+release_version = 2.1.1
 ; DEBUG LEVEL: For production run set to 0, otherwise device will leak RAM while running!
 ; 0=None, 1=Error, 2=Warn, 3=Info, 4=Debug, 5=Verbose
 debug_level = 3
diff --git a/src/hal/lopy4.h b/src/hal/lopy4.h
index 8072dfd0..fd99a7d7 100644
--- a/src/hal/lopy4.h
+++ b/src/hal/lopy4.h
@@ -10,7 +10,6 @@
 // Hardware related definitions for Pycom LoPy4 Board
 
 #define HAS_LORA 1       // comment out if device shall not send data via LoRa
-#define LORA_RST  LMIC_UNUSED_PIN // reset pin of lora chip is not wired von LoPy4
 
 //#defin HAS_SPI 1        // comment out if device shall not send data via SPI
 // pin definitions for local wired SPI slave interface
diff --git a/src/lmic_config.h b/src/lmic_config.h
index 992e4a18..d5dcfdbe 100644
--- a/src/lmic_config.h
+++ b/src/lmic_config.h
@@ -18,9 +18,10 @@
 
 // use interrupts only if LORA_IRQ and LORA_DIO are connected to interrupt
 // capable and separate GPIO pins on your board, if not don't enable
-#if (LORA_IRQ) != (LORA_IO1)
-#define LMIC_USE_INTERRUPTS 1
-#endif
+// note: this feature can't be used on ESP32 unless PR #556 of MCCI LMIC was merged
+//#if (LORA_IRQ) != (LORA_IO1)
+//#define LMIC_USE_INTERRUPTS 1
+//#endif
 
 // avoid lmic warning if we don't configure radio in case we haven't one
 #if !(defined(CFG_sx1272_radio) || defined(CFG_sx1276_radio))
diff --git a/src/macsniff.cpp b/src/macsniff.cpp
index d47df342..e5044039 100644
--- a/src/macsniff.cpp
+++ b/src/macsniff.cpp
@@ -102,6 +102,10 @@ void IRAM_ATTR mac_add(uint8_t *paddr, int8_t rssi, snifftype_t sniff_type) {
 
 uint16_t mac_analyze(MacBuffer_t MacBuffer) {
 
+  uint32_t *mac; // pointer to shortened 4 byte MAC
+  uint32_t saltedmac;
+  uint16_t hashedmac;
+
   if ((cfg.rssilimit) &&
       (MacBuffer.rssi < cfg.rssilimit)) { // rssi is negative value
     ESP_LOGI(TAG, "%s RSSI %d -> ignoring (limit: %d)",
@@ -124,8 +128,6 @@ uint16_t mac_analyze(MacBuffer_t MacBuffer) {
     }
   };
 
-  uint32_t *mac; // pointer to shortened 4 byte MAC
-
   // only last 3 MAC Address bytes are used for MAC address anonymization
   // but since it's uint32 we take 4 bytes to avoid 1st value to be 0.
   // this gets MAC in msb (= reverse) order, but doesn't matter for hashing it.
@@ -136,12 +138,12 @@ uint16_t mac_analyze(MacBuffer_t MacBuffer) {
   // https://en.wikipedia.org/wiki/MAC_Address_Anonymization
 
   // reversed 4 byte MAC added to current salt
-  const uint32_t saltedmac = *mac + salt;
+  saltedmac = *mac + salt;
 
   // hashed 4 byte MAC
   // to save RAM, we use only lower 2 bytes of hash, since collisions don't
   // matter in our use case
-  const uint16_t hashedmac = hash((const char *)&saltedmac, 4);
+  hashedmac = hash((const char *)&saltedmac, 4);
 
   auto newmac = macs.insert(hashedmac); // add hashed MAC, if new unique
   bool added =
diff --git a/src/mqttclient.cpp b/src/mqttclient.cpp
index 6821a629..b890c920 100644
--- a/src/mqttclient.cpp
+++ b/src/mqttclient.cpp
@@ -95,14 +95,23 @@ void mqtt_client_task(void *param) {
                      MQTT_KEEPALIVE * 1000 / portTICK_PERIOD_MS) != pdTRUE)
         continue;
 
-      // prepare data to send
-      char buffer[PAYLOAD_BUFFER_SIZE + 3];
-      snprintf(buffer, msg.MessageSize + 3, "%u/%s", msg.MessagePort,
-               msg.Message);
+      // prepare mqtt topic
+      char topic[16];
+      snprintf(topic, 16, "%s/%u", MQTT_OUTTOPIC, msg.MessagePort);
+      size_t out_len = 0;
 
-      // send data to mqtt server and delete sent item from queue
-      if (mqttClient.publish(MQTT_OUTTOPIC, buffer)) {
-        ESP_LOGI(TAG, "%d byte(s) sent to MQTT server", msg.MessageSize + 2);
+      // get length of base64 encoded message
+      mbedtls_base64_encode(NULL, 0, &out_len, (unsigned char *)msg.Message,
+                            msg.MessageSize);
+
+      // base64 encode the message
+      unsigned char encoded[out_len];
+      mbedtls_base64_encode(encoded, out_len, &out_len,
+                            (unsigned char *)msg.Message, msg.MessageSize);
+
+      // send encoded message to mqtt server and delete it from queue
+      if (mqttClient.publish(topic, (const char *)encoded, out_len)) {
+        ESP_LOGD(TAG, "%u bytes sent to MQTT server", out_len);
         xQueueReceive(MQTTSendQueue, &msg, (TickType_t)0);
       } else
         ESP_LOGD(TAG, "Couldn't sent message to MQTT server");
@@ -115,19 +124,29 @@ void mqtt_client_task(void *param) {
   } // while (1)
 }
 
+// process incoming MQTT messages
+void mqtt_callback(MQTTClient *client, char *topic, char *payload, int length) {
+  if (strcmp(topic, MQTT_INTOPIC) == 0) {
+
+    // get length of base64 encoded message
+    size_t out_len = 0;
+    mbedtls_base64_decode(NULL, 0, &out_len, (unsigned char *)payload, length);
+
+    // decode the base64 message
+    unsigned char decoded[out_len];
+    mbedtls_base64_decode(decoded, out_len, &out_len, (unsigned char *)payload,
+                          length);
+
+    rcommand(decoded, out_len);
+  }
+}
+
 // enqueue outgoing messages in MQTT send queue
 void mqtt_enqueuedata(MessageBuffer_t *message) {
   if (xQueueSendToBack(MQTTSendQueue, (void *)message, (TickType_t)0) != pdTRUE)
     ESP_LOGW(TAG, "MQTT sendqueue is full");
 }
 
-// process incoming MQTT messages
-void mqtt_callback(MQTTClient *client, char topic[], char payload[],
-                   int length) {
-  if (strcmp(topic, MQTT_INTOPIC) == 0)
-    rcommand((const uint8_t *)payload, (const uint8_t)length);
-}
-
 void mqtt_queuereset(void) { xQueueReset(MQTTSendQueue); }
 
 uint32_t mqtt_queuewaiting(void) {
diff --git a/src/reset.cpp b/src/reset.cpp
index 8332589d..3bd2a619 100644
--- a/src/reset.cpp
+++ b/src/reset.cpp
@@ -81,8 +81,7 @@ void do_after_reset(void) {
            runmode[RTC_runmode]);
 }
 
-void enter_deepsleep(const uint64_t wakeup_sec = 60,
-                     gpio_num_t wakeup_gpio = GPIO_NUM_MAX) {
+void enter_deepsleep(const uint64_t wakeup_sec, gpio_num_t wakeup_gpio) {
 
   ESP_LOGI(TAG, "Preparing to sleep...");