diff --git a/README.md b/README.md
index 7d0a8c15..c4ff5856 100644
--- a/README.md
+++ b/README.md
@@ -63,7 +63,8 @@ Depending on board hardware following features are supported:
 - IF482 (serial) and DCF77 (gpio) time telegram generator
 - 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)
+- 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](https://github.com/cyberman54/ESP32-Paxcounter/blob/master/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>
@@ -207,8 +208,11 @@ There in the sensor configuration select "TheThingsNetwork" and set Decoding Pro
 # SD-card
 Data can be stored on an SD-card if one is availabe. Simply choose the file in src/hal and add the following lines to your hal-file:
 
-    #define HAS_SDCARD 1     // this board has an SD-card-reader/writer
-    // Pins for SD-card
+    #define HAS_SDCARD 1     // SD-card-reader/writer, using SPI interface
+	OR
+	#define HAS_SDCARD 2     // SD-card-reader/writer, using SDMMC interface
+
+    // Pins for SPI interface
     #define SDCARD_CS   (13) // fill in the correct numbers for your board
     #define SDCARD_MOSI (15)
     #define SDCARD_MISO (2)
diff --git a/build.py b/build.py
index c4f3ccc3..a3b3c13b 100644
--- a/build.py
+++ b/build.py
@@ -66,16 +66,20 @@ myboard = mykeys["board"]
 myuploadspeed = mykeys["upload_speed"]
 env.Replace(BOARD=myboard)
 env.Replace(UPLOAD_SPEED=myuploadspeed)
+print('\033[94m' + "Target board: " + myboard + " @ " + myuploadspeed + "bps" + '\033[0m')
 
 # re-set partition table
 mypartitiontable = config.get("env", "board_build.partitions")
 board = env.BoardConfig(myboard)
 board.manifest['build']['partitions'] = mypartitiontable
-
-# display target
-print('\033[94m' + "TARGET BOARD: " + myboard + " @ " + myuploadspeed + "bps" + '\033[0m')
 print('\033[94m' + "Partition table: " + mypartitiontable + '\033[0m')
 
+# set display library
+if "display_library" in mykeys:
+    mydisplay = mykeys["display_library"]
+    env.Append(display_library=mydisplay)
+    print('\033[94m' + "Display library: " + mydisplay + '\033[0m')
+
 # parse ota key file
 with open(otakeyfile) as myfile:
     for line in myfile:
diff --git a/include/cyclic.h b/include/cyclic.h
index 44c475e8..0fdf38b1 100644
--- a/include/cyclic.h
+++ b/include/cyclic.h
@@ -5,6 +5,7 @@
 #include "senddata.h"
 #include "rcommand.h"
 #include "spislave.h"
+#include "mqttclient.h"
 #include "bmesensor.h"
 #include "display.h"
 #include "sds011read.h"
diff --git a/include/display.h b/include/display.h
index c6b39033..b5219a32 100644
--- a/include/display.h
+++ b/include/display.h
@@ -5,7 +5,7 @@
 #include "qrcode.h"
 
 #if (HAS_DISPLAY) == 1
-#include <ss_oled.h>
+#include <OneBitDisplay.h>
 #elif (HAS_DISPLAY) == 2
 #include <TFT_eSPI.h>
 #endif
diff --git a/include/mqttclient.h b/include/mqttclient.h
new file mode 100644
index 00000000..9bb90364
--- /dev/null
+++ b/include/mqttclient.h
@@ -0,0 +1,26 @@
+#ifndef _MQTTCLIENT_H
+#define _MQTTCLIENT_H
+
+#include "globals.h"
+#include "rcommand.h"
+#include <ETH.h>
+#include <PubSubClient.h>
+
+#define MQTT_INTOPIC "paxcounter_in/"
+#define MQTT_OUTTOPIC "paxcounter_out/"
+#define MQTT_PORT 1883
+#define MQTT_SERVER "broker.hivemq.com"
+#define MQTT_RETRYSEC 10 // retry reconnect every 10 seconds
+
+extern TaskHandle_t mqttTask;
+extern PubSubClient mqttClient;
+
+void mqtt_enqueuedata(MessageBuffer_t *message);
+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(char *topic, byte *payload, unsigned int length);
+void NetworkEvent(WiFiEvent_t event);
+esp_err_t mqtt_init(void);
+
+#endif // _MQTTCLIENT_H
\ No newline at end of file
diff --git a/include/power.h b/include/power.h
index 795fbb87..d11235c0 100644
--- a/include/power.h
+++ b/include/power.h
@@ -18,6 +18,22 @@
 #define BAT_MIN_VOLTAGE 3100 // millivolts
 #endif
 
+#ifndef PMU_CHG_CUTOFF
+#ifdef HAS_PMU
+#define PMU_CHG_CUTOFF AXP202_TARGET_VOL_4_2V
+#elif defined HAS_IP5306
+#define PMU_CHG_CUTOFF 0
+#endif
+#endif
+
+#ifndef PMU_CHG_CURRENT
+#ifdef HAS_PMU
+#define PMU_CHG_CURRENT AXP1XX_CHARGE_CUR_450MA
+#elif defined HAS_IP5306
+#define PMU_CHG_CURRENT 2
+#endif
+#endif
+
 typedef uint8_t (*mapFn_t)(uint16_t, uint16_t, uint16_t);
 
 uint16_t read_voltage(void);
@@ -37,10 +53,14 @@ void AXP192_showstatus(void);
 #endif // HAS_PMU
 
 #ifdef HAS_IP5306
+void IP5306_init(void);
 void printIP5306Stats(void);
 uint8_t IP5306_GetPowerSource(void);
 uint8_t IP5306_GetBatteryLevel(void);
 uint8_t IP5306_GetBatteryFull(void);
+void IP5306_SetChargerEnabled(uint8_t v);
+void IP5306_SetChargeCutoffVoltage(uint8_t v);
+void IP5306_SetEndChargeCurrentDetection(uint8_t v);
 #endif
 
 // The following map functions were taken from
diff --git a/include/sdcard.h b/include/sdcard.h
index 4323c6a3..7102c460 100644
--- a/include/sdcard.h
+++ b/include/sdcard.h
@@ -4,14 +4,42 @@
 #include <globals.h>
 #include <stdio.h>
 #include <SPI.h>
+
+#ifdef HAS_SDCARD
+#if HAS_SDCARD == 1
 #include <mySD.h>
+#elif HAS_SDCARD == 2
+#include <SD_MMC.h>
+#else
+#error HAS_SDCARD unknown card reader value, must be either 1 or 2
+#endif
+#endif
 
+#ifdef HAS_SDS011
 #include "sds011read.h"
+#endif
 
-#define SDCARD_FILE_NAME       "paxcount.%02d"
-#define SDCARD_FILE_HEADER     "date, time, wifi, bluet"
+#ifndef SDCARD_CS
+#define SDCARD_CS SS
+#endif
 
-bool sdcard_init( void );
-void sdcardWriteData( uint16_t, uint16_t);
+#ifndef SDCARD_MOSI
+#define SDCARD_MOSI MOSI
+#endif
+
+#ifndef SDCARD_MISO
+#define SDCARD_MISO MISO
+#endif
+
+#ifndef SDCARD_SCLK
+#define SDCARD_SCLK SCK
+#endif
+
+#define SDCARD_FILE_NAME "/paxcount.%02d"
+#define SDCARD_FILE_HEADER "date, time, wifi, bluet"
+
+bool sdcard_init(void);
+void sdcardWriteData(uint16_t, uint16_t);
+static void createFile(void);
 
 #endif
diff --git a/include/senddata.h b/include/senddata.h
index 7be85016..fd31f884 100644
--- a/include/senddata.h
+++ b/include/senddata.h
@@ -2,6 +2,7 @@
 #define _SENDDATA_H
 
 #include "spislave.h"
+#include "mqttclient.h"
 #include "cyclic.h"
 #include "sensor.h"
 #include "lorawan.h"
diff --git a/platformio.ini b/platformio.ini
index 1720b4f1..7030b54f 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -33,6 +33,7 @@ halfile = generic.h
 ;halfile = tinypicomatrix.h
 ;halfile = m5core.h
 ;halfile = m5fire.h
+;halfile = olimexpoeiso.h
 
 [platformio]
 ; upload firmware to board with usb cable
@@ -45,7 +46,7 @@ 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 = 1.9.991
+release_version = 1.9.996
 ; 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
@@ -53,26 +54,28 @@ extra_scripts = pre:build.py
 otakeyfile = ota.conf
 lorakeyfile = loraconf.h
 lmicconfigfile = lmic_config.h
-platform_espressif32 = espressif32@1.12.1
+platform_espressif32 = espressif32@1.12.2
 monitor_speed = 115200
-upload_speed = 115200
+upload_speed = 115200 ; set by build.py and taken from hal file
+display_library = ; set by build.py and taken from hal file
 lib_deps_lora =
     MCCI LoRaWAN LMIC library@3.2.0 ; MCCI LMIC by Terrill Moore
 lib_deps_display =
-    ss_oled@4.1.3 ; fast and small OLED lib by Larry Bank
-    BitBang_I2C@2.1.1
+    ;OneBitDisplay@>1.4.0
+    https://github.com/bitbank2/OneBitDisplay.git
     QRCode@0.0.1
-    TFT_eSPI@2.2.2
-lib_deps_matrix_display =
+    BitBang_I2C@2.1.1
+    TFT_eSPI@>=2.2.8
+lib_deps_ledmatrix =
     Ultrathin_LED_Matrix@>=1.0.0
 lib_deps_rgbled =
     SmartLeds@>=1.2.0
 lib_deps_gps =
     1655@>=1.0.2 ; #1655 TinyGPSPlus by Mikal Hart
 lib_deps_sensors =
-    Adafruit Unified Sensor@>=1.1.2
+    Adafruit Unified Sensor@>=1.1.3
     Adafruit BME280 Library@>=2.0.2
-    Adafruit BMP085 Library@>=1.0.1
+    Adafruit BMP085 Library@>=1.1.0
     BSEC Software Library@1.5.1474
     https://github.com/ricki-z/SDS011.git
 lib_deps_basic =
@@ -80,8 +83,9 @@ lib_deps_basic =
     76@>=1.2.4 ; #76 Timezone by Jack Christensen
     274@>=2.3.4 ; #274 RTC by Michael Miller
     SimpleButton
-    AXP202X_Library@>=1.1.0 ; AXP202 PMU lib by Lewis He
+    AXP202X_Library@>=1.1.1 ; AXP202 PMU lib by Lewis He
     esp32-micro-sdcard
+    PubSubClient@>=2.8.0
 lib_deps_all =
     ${common.lib_deps_basic}
     ${common.lib_deps_lora}
@@ -89,7 +93,7 @@ lib_deps_all =
     ${common.lib_deps_rgbled}
     ${common.lib_deps_gps}
     ${common.lib_deps_sensors}
-    ${common.lib_deps_matrix_display}
+    ${common.lib_deps_ledmatrix}
 build_flags_basic =
     -include "src/hal/${board.halfile}"
     -include "src/paxcounter.conf"
@@ -110,7 +114,7 @@ framework = arduino
 board = esp32dev
 board_build.partitions = min_spiffs.csv
 upload_speed = ${common.upload_speed}
-;upload_port = COM5
+;upload_port = COM7
 platform = ${common.platform_espressif32}
 lib_deps = ${common.lib_deps_all}
 build_flags = ${common.build_flags_all}
diff --git a/src/cyclic.cpp b/src/cyclic.cpp
index 31175ff9..77e7439d 100644
--- a/src/cyclic.cpp
+++ b/src/cyclic.cpp
@@ -52,6 +52,11 @@ void doHousekeeping() {
   ESP_LOGD(TAG, "spiloop %d bytes left | Taskstate = %d",
            uxTaskGetStackHighWaterMark(spiTask), eTaskGetState(spiTask));
 #endif
+#ifdef HAS_MQTT
+  ESP_LOGD(TAG, "MQTTloop %d bytes left | Taskstate = %d",
+           uxTaskGetStackHighWaterMark(mqttTask), eTaskGetState(mqttTask));
+  mqttClient.loop();
+#endif
 
 #if (defined HAS_DCF77 || defined HAS_IF482)
   ESP_LOGD(TAG, "Clockloop %d bytes left | Taskstate = %d",
diff --git a/src/display.cpp b/src/display.cpp
index 732b3063..162fa6b3 100644
--- a/src/display.cpp
+++ b/src/display.cpp
@@ -49,24 +49,29 @@ static int dp_row = 0, dp_col = 0, dp_font = 0;
 
 QRCode qrcode;
 
+#ifdef HAS_DISPLAY
 #if (HAS_DISPLAY) == 1
-SSOLED ssoled;
+OBDISP ssoled;
 #elif (HAS_DISPLAY) == 2
 TFT_eSPI tft = TFT_eSPI();
+#else
+#error Unknown display type specified in hal file
+#endif
 #endif
 
 void dp_setup(int contrast) {
 
 #if (HAS_DISPLAY) == 1 // I2C OLED
-  int rc = oledInit(&ssoled, OLED_TYPE, OLED_ADDR, MY_DISPLAY_FLIP,
-                    MY_DISPLAY_INVERT, USE_HW_I2C, MY_DISPLAY_SDA,
-                    MY_DISPLAY_SCL, MY_DISPLAY_RST,
-                    OLED_FREQUENCY); // use standard I2C bus at 400Khz
+
+  int rc = obdI2CInit(&ssoled, OLED_TYPE, OLED_ADDR, MY_DISPLAY_FLIP,
+                      MY_DISPLAY_INVERT, USE_HW_I2C, MY_DISPLAY_SDA,
+                      MY_DISPLAY_SCL, MY_DISPLAY_RST,
+                      OLED_FREQUENCY); // use standard I2C bus at 400Khz
   assert(rc != OLED_NOT_FOUND);
 
   // set display buffer
-  oledSetBackBuffer(&ssoled, displaybuf);
-  oledSetTextWrap(&ssoled, true);
+  obdSetBackBuffer(&ssoled, displaybuf);
+  obdSetTextWrap(&ssoled, true);
   dp_font = MY_FONT_NORMAL;
 
 #elif (HAS_DISPLAY) == 2 // SPI TFT
@@ -466,7 +471,7 @@ void dp_setTextCursor(int x, int y) {
 
 #if (HAS_DISPLAY) == 1
   dp_row = y;
-  oledSetCursor(&ssoled, dp_col, dp_row);
+  obdSetCursor(&ssoled, dp_col, dp_row);
 
 #elif (HAS_DISPLAY) == 2
   switch (dp_font >> 1) {
@@ -538,8 +543,8 @@ void dp_printf(const char *format, ...) {
   }
   va_end(arg);
 #if (HAS_DISPLAY) == 1
-  oledWriteString(&ssoled, 0, -1, dp_row, temp, dp_font >> 1, dp_font & 0x01,
-                  false);
+  obdWriteString(&ssoled, 0, -1, dp_row, temp, dp_font >> 1, dp_font & 0x01,
+                 false);
 #elif (HAS_DISPLAY) == 2
   tft.printf(temp);
 #endif
@@ -550,7 +555,7 @@ void dp_printf(const char *format, ...) {
 
 void dp_dump(uint8_t *pBuffer) {
 #if (HAS_DISPLAY) == 1
-  oledDumpBuffer(&ssoled, pBuffer);
+  obdDumpBuffer(&ssoled, pBuffer);
 #elif (HAS_DISPLAY) == 2
   // probably oled buffer stucture is not suitable for tft -> to be checked
   tft.drawBitmap(0, 0, pBuffer, MY_DISPLAY_WIDTH, MY_DISPLAY_HEIGHT,
@@ -561,7 +566,7 @@ void dp_dump(uint8_t *pBuffer) {
 void dp_clear(void) {
   dp_setTextCursor(0, 0);
 #if (HAS_DISPLAY) == 1
-  oledFill(&ssoled, 0, 1);
+  obdFill(&ssoled, 0, 1);
 #elif (HAS_DISPLAY) == 2
   tft.fillScreen(MY_DISPLAY_BGCOLOR);
 #endif
@@ -569,7 +574,7 @@ void dp_clear(void) {
 
 void dp_contrast(uint8_t contrast) {
 #if (HAS_DISPLAY) == 1
-  oledSetContrast(&ssoled, contrast);
+  obdSetContrast(&ssoled, contrast);
 #elif (HAS_DISPLAY) == 2
   // to do: gamma correction for TFT
 #endif
@@ -577,7 +582,7 @@ void dp_contrast(uint8_t contrast) {
 
 void dp_power(uint8_t screenon) {
 #if (HAS_DISPLAY) == 1
-  oledPower(&ssoled, screenon);
+  obdPower(&ssoled, screenon);
 #elif (HAS_DISPLAY) == 2
   // to come
 #endif
@@ -590,7 +595,7 @@ void dp_shutdown(void) {
     ESP_LOGV(TAG, "[%0.3f] i2c mutex lock failed", millis() / 1000.0);
   else {
     cfg.screenon = 0;
-    oledPower(&ssoled, false);
+    obdPower(&ssoled, false);
     delay(DISPLAYREFRESH_MS / 1000 * 1.1);
     I2C_MUTEX_UNLOCK(); // release i2c bus access
   }
@@ -630,7 +635,7 @@ void dp_fillRect(uint16_t x, uint16_t y, uint16_t width, uint16_t height,
                  uint8_t bRender) {
 #if (HAS_DISPLAY) == 1
   for (uint16_t xi = x; xi < x + width; xi++)
-    oledDrawLine(&ssoled, xi, y, xi, y + height - 1, bRender);
+    obdDrawLine(&ssoled, xi, y, xi, y + height - 1, 1, bRender);
 #elif (HAS_DISPLAY) == 2
   tft.fillRect(x, y, width, height, MY_DISPLAY_FGCOLOR);
 #endif
diff --git a/src/hal/generic.h b/src/hal/generic.h
index 87be95f5..0010f69d 100644
--- a/src/hal/generic.h
+++ b/src/hal/generic.h
@@ -1,6 +1,7 @@
 // clang-format off
 // upload_speed 115200
 // board esp32dev
+// display_library lib_deps_oled_display
 
 #ifndef _GENERIC_H
 #define _GENERIC_H
diff --git a/src/hal/m5core.h b/src/hal/m5core.h
index d441bcbe..17dc7f22 100644
--- a/src/hal/m5core.h
+++ b/src/hal/m5core.h
@@ -37,7 +37,12 @@
 #define HAS_LED NOT_A_PIN // no on board LED (?)
 #define HAS_BUTTON (39) // on board button A
 
-#define HAS_IP5306 1
+// power management settings
+#define HAS_IP5306 1 // has IP5306 chip
+#define PMU_CHG_CURRENT 2 // battery charge current
+// possible values: 0:200mA, 1:400mA, *2:500mA, 3:600mA
+#define PMU_CHG_CUTOFF 0 // battery charge cutoff
+// possible values: *0:4.2V, 1:4.3V, 2:4.35V, 3:4.4V
 
 // GPS settings
 #define HAS_GPS 1 // use on board GPS
diff --git a/src/hal/m5fire.h b/src/hal/m5fire.h
index 553493be..9572f6bf 100644
--- a/src/hal/m5fire.h
+++ b/src/hal/m5fire.h
@@ -41,7 +41,12 @@
 #define HAS_RGB_LED SmartLed rgb_led(LED_SK6812, RGB_LED_COUNT, GPIO_NUM_15) // LED_SK6812 RGB LED on GPIO15
 #define HAS_BUTTON (39) // on board button A
 
-#define HAS_IP5306 1
+// power management settings
+#define HAS_IP5306 1 // has IP5306 chip
+#define PMU_CHG_CURRENT 2 // battery charge current
+// possible values: 0:200mA, 1:400mA, *2:500mA, 3:600mA
+#define PMU_CHG_CUTOFF 0 // battery charge cutoff
+// possible values: *0:4.2V, 1:4.3V, 2:4.35V, 3:4.4V
 
 // GPS settings
 #define HAS_GPS 0 // use on board GPS
diff --git a/src/hal/olimexpoeiso.h b/src/hal/olimexpoeiso.h
new file mode 100644
index 00000000..70856336
--- /dev/null
+++ b/src/hal/olimexpoeiso.h
@@ -0,0 +1,24 @@
+// clang-format off
+// upload_speed 921600
+// board esp32-poe-iso
+
+#ifndef _OLIMEXPOEISO_H
+#define _OLIMEXPOEISO_H
+
+#include <stdint.h>
+
+// enable only if you want to store a local paxcount table on the device
+//#define HAS_SDCARD 2 // this board has a SDMMC card-reader/writer
+
+// enable only if you want to send paxcount via ethernet port to mqtt server
+#define HAS_MQTT 1  // use MQTT on ethernet interface
+
+//#define BAT_MEASURE_ADC ADC1_GPIO35_CHANNEL // battery probe GPIO pin -> ADC1_CHANNEL_7
+//#define BAT_VOLTAGE_DIVIDER 2 // voltage divider 470k/470k on board
+#define BAT_MEASURE_ADC ADC1_GPIO39_CHANNEL // external power probe GPIO pin
+#define BAT_VOLTAGE_DIVIDER 2.1277f // voltage divider 47k/442k on board
+
+#define HAS_BUTTON KEY_BUILTIN // on board button
+#define HAS_LED NOT_A_PIN // no on board LED
+
+#endif
diff --git a/src/hal/ttgobeam10.h b/src/hal/ttgobeam10.h
index abebe0d5..080b5a5d 100644
--- a/src/hal/ttgobeam10.h
+++ b/src/hal/ttgobeam10.h
@@ -9,7 +9,7 @@
 
 /* 
 Hardware related definitions for TTGO T-Beam board
-(only) for newer T-Beam version T22_V10
+for T-Beam versions T22_V10 + T22_V11
 pinouts taken from https://github.com/lewisxhe/TTGO-T-Beam
 
 /// Button functions: ///
@@ -20,7 +20,7 @@ User, long press -> send LORA message
 Reset -> reset device
 */
 
-#define HAS_DISPLAY 1
+//#define HAS_DISPLAY 1
 #define MY_DISPLAY_SDA SDA
 #define MY_DISPLAY_SCL SCL
 #define MY_DISPLAY_RST NOT_A_PIN
@@ -29,11 +29,18 @@ Reset -> reset device
 #define HAS_LORA 1       // comment out if device shall not send data via LoRa
 #define CFG_sx1276_radio 1 // HPD13A LoRa SoC
 #define HAS_BUTTON GPIO_NUM_38 // middle on board button
-#define HAS_PMU 1 // AXP192 power management chip
-#define PMU_INT GPIO_NUM_35 // AXP192 interrupt
-
 #define HAS_LED NOT_A_PIN
 
+// power management settings
+#define HAS_PMU 1 // has AXP192 chip
+#define PMU_INT GPIO_NUM_35 // battery interrupt
+#define PMU_CHG_CURRENT AXP1XX_CHARGE_CUR_1000MA // battery charge current
+// possible values (mA):
+// 100/190/280/360/450/550/630/700/780/880/960/1000/1080/1160/1240/1320
+#define PMU_CHG_CUTOFF AXP202_TARGET_VOL_4_2V // battery charge cutoff
+// possible values (V):
+// 4_1/4_15/4_2/4_36
+
 // GPS settings
 #define HAS_GPS 1 // use on board GPS
 #define GPS_SERIAL 9600, SERIAL_8N1, GPIO_NUM_34, GPIO_NUM_12 // UBlox NEO 6M
diff --git a/src/main.cpp b/src/main.cpp
index 3d83ebce..17a8fa04 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -29,6 +29,7 @@ Task          Core  Prio  Purpose
 -------------------------------------------------------------------------------
 ledloop       0     3     blinks LEDs
 spiloop       0     2     reads/writes data on spi interface
+mqttloop      0     2     reads/writes data on ETH interface
 IDLE          0     0     ESP32 arduino scheduler -> runs wifi sniffer
 
 lmictask      1     2     MCCI LMiC LORAWAN stack
@@ -185,14 +186,22 @@ void setup() {
   digitalWrite(EXT_POWER_SW, EXT_POWER_ON);
   strcat_P(features, " VEXT");
 #endif
+
+#if defined HAS_PMU || defined HAS_IP5306
 #ifdef HAS_PMU
   AXP192_init();
+#elif defined HAS_IP5306
+  IP5306_init();
+#endif
   strcat_P(features, " PMU");
 #endif
 
   // read (and initialize on first run) runtime settings from NVRAM
   loadConfig(); // includes initialize if necessary
 
+  // now that we are powered, we scan i2c bus for devices
+  i2c_scan();
+
 // initialize display
 #ifdef HAS_DISPLAY
   strcat_P(features, " OLED");
@@ -201,9 +210,6 @@ void setup() {
   dp_init(RTC_runmode == RUNMODE_POWERCYCLE ? true : false);
 #endif
 
-  // scan i2c bus for devices
-  i2c_scan();
-
 #ifdef BOARD_HAS_PSRAM
   assert(psramFound());
   ESP_LOGI(TAG, "PSRAM found and initialized");
@@ -325,6 +331,12 @@ void setup() {
   assert(spi_init() == ESP_OK);
 #endif
 
+// initialize MQTT
+#ifdef HAS_MQTT
+  strcat_P(features, " MQTT");
+  assert(mqtt_init() == ESP_OK);
+#endif
+
 #ifdef HAS_SDCARD
   if (sdcard_init())
     strcat_P(features, " SD");
diff --git a/src/mqttclient.cpp b/src/mqttclient.cpp
new file mode 100644
index 00000000..bfd11319
--- /dev/null
+++ b/src/mqttclient.cpp
@@ -0,0 +1,163 @@
+#ifdef HAS_MQTT
+
+#include "mqttclient.h"
+
+static const char TAG[] = __FILE__;
+
+QueueHandle_t MQTTSendQueue;
+TaskHandle_t mqttTask;
+
+WiFiClient EthClient;
+PubSubClient mqttClient(EthClient);
+
+void NetworkEvent(WiFiEvent_t event) {
+  switch (event) {
+  case SYSTEM_EVENT_ETH_START:
+    ESP_LOGI(TAG, "Ethernet link layer started");
+    ETH.setHostname(ETH.macAddress().c_str());
+    break;
+  case SYSTEM_EVENT_ETH_CONNECTED:
+    ESP_LOGI(TAG, "Network link connected");
+    break;
+  case SYSTEM_EVENT_ETH_GOT_IP:
+    ESP_LOGI(TAG, "ETH MAC: %s", ETH.macAddress().c_str());
+    ESP_LOGI(TAG, "IPv4: %s", ETH.localIP().toString().c_str());
+    ESP_LOGI(TAG, "Link Speed: %d Mbps %s", ETH.linkSpeed(),
+             ETH.fullDuplex() ? "full duplex" : "half duplex");
+    mqtt_connect(MQTT_SERVER, MQTT_PORT);
+    break;
+  case SYSTEM_EVENT_ETH_DISCONNECTED:
+    ESP_LOGI(TAG, "Network link disconnected");
+    break;
+  case SYSTEM_EVENT_ETH_STOP:
+    ESP_LOGI(TAG, "Ethernet link layer stopped");
+    break;
+  default:
+    break;
+  }
+}
+
+int mqtt_connect(const char *my_host, const uint16_t my_port) {
+  IPAddress mqtt_server_ip;
+
+  static String clientId = "paxcounter-" + ETH.macAddress();
+  ESP_LOGI(TAG, "MQTT name is %s", clientId.c_str());
+
+  // resolve server
+  if (WiFi.hostByName(my_host, mqtt_server_ip)) {
+    ESP_LOGI(TAG, "Attempting to connect to %s [%s]", my_host,
+             mqtt_server_ip.toString().c_str());
+  } else {
+    ESP_LOGI(TAG, "Could not resolve %s", my_host);
+    return -1;
+  }
+
+  // attempt to connect to MQTT server
+  if (EthClient.connect(mqtt_server_ip, my_port, HOMECYCLE * 2 * 1000)) {
+    mqttClient.setServer(mqtt_server_ip, my_port);
+    mqttClient.setKeepAlive(HOMECYCLE * 2);
+    mqttClient.setCallback(mqtt_callback);
+
+    if (mqttClient.connect(clientId.c_str())) {
+      ESP_LOGI(TAG, "MQTT server connected, subscribing...");
+      mqttClient.publish(MQTT_OUTTOPIC, clientId.c_str());
+      mqttClient.subscribe(MQTT_INTOPIC);
+      ESP_LOGI(TAG, "MQTT topic subscribed");
+    } else {
+      ESP_LOGW(TAG, "MQTT server not responding, retrying later");
+      return -1;
+    }
+  } else {
+    ESP_LOGW(TAG, "MQTT server not connected, retrying later");
+    return -1;
+  }
+}
+
+void mqtt_client_task(void *param) {
+
+  MessageBuffer_t msg;
+
+  while (1) {
+
+    // fetch next or wait for payload to send from queue
+    if (xQueueReceive(MQTTSendQueue, &msg, portMAX_DELAY) != pdTRUE) {
+      ESP_LOGE(TAG, "Premature return from xQueueReceive() with no data!");
+      continue;
+    }
+
+    // send data to mqtt server, if we are connected
+    if (mqttClient.connected()) {
+      mqttClient.beginPublish(MQTT_OUTTOPIC, msg.MessageSize + 2, false);
+      mqttClient.write(msg.MessagePort);
+      mqttClient.write('/');
+      mqttClient.write(msg.Message, msg.MessageSize);
+      if (mqttClient.endPublish()) {
+        ESP_LOGI(TAG, "%d byte(s) sent to MQTT", msg.MessageSize + 2);
+        continue; // while(1)
+      } else
+        goto reconnect;
+
+    } else {
+
+      // attempt to reconnect to MQTT server
+    reconnect:
+      mqtt_enqueuedata(&msg); // postpone the undelivered message
+      delay(MQTT_RETRYSEC * 1000);
+      mqtt_connect(MQTT_SERVER, MQTT_PORT);
+    }
+  } // while(1)
+}
+
+esp_err_t mqtt_init(void) {
+  assert(SEND_QUEUE_SIZE);
+  MQTTSendQueue = xQueueCreate(SEND_QUEUE_SIZE, sizeof(MessageBuffer_t));
+  if (MQTTSendQueue == 0) {
+    ESP_LOGE(TAG, "Could not create MQTT send queue. Aborting.");
+    return ESP_FAIL;
+  }
+  ESP_LOGI(TAG, "MQTT send queue created, size %d Bytes",
+           SEND_QUEUE_SIZE * PAYLOAD_BUFFER_SIZE);
+
+  ESP_LOGI(TAG, "Starting MQTTloop...");
+  xTaskCreate(mqtt_client_task, "mqttloop", 4096, (void *)NULL, 2, &mqttTask);
+
+  WiFi.onEvent(NetworkEvent);
+  ETH.begin();
+
+  return ESP_OK;
+}
+
+void mqtt_enqueuedata(MessageBuffer_t *message) {
+  // enqueue message in MQTT send queue
+  BaseType_t ret;
+  MessageBuffer_t DummyBuffer;
+  sendprio_t prio = message->MessagePrio;
+
+  switch (prio) {
+  case prio_high:
+    // clear space in queue if full, then fallthrough to normal
+    if (!uxQueueSpacesAvailable(MQTTSendQueue))
+      xQueueReceive(MQTTSendQueue, &DummyBuffer, (TickType_t)0);
+  case prio_normal:
+    ret = xQueueSendToFront(MQTTSendQueue, (void *)message, (TickType_t)0);
+    break;
+  case prio_low:
+  default:
+    ret = xQueueSendToBack(MQTTSendQueue, (void *)message, (TickType_t)0);
+    break;
+  }
+  if (ret != pdTRUE)
+    ESP_LOGW(TAG, "MQTT sendqueue is full");
+}
+
+void mqtt_callback(char *topic, byte *payload, unsigned int length) {
+  String s = "";
+  for (int i = 0; i < length; i++)
+    s += (char)payload[i];
+  ESP_LOGD(TAG, "MQTT: Received %u byte(s) of payload [%s]", length, s);
+  // rcommand(payload, length);
+}
+
+void mqtt_queuereset(void) { xQueueReset(MQTTSendQueue); }
+
+#endif // HAS_MQTT
\ No newline at end of file
diff --git a/src/power.cpp b/src/power.cpp
index 2c6012b5..5d3d770e 100644
--- a/src/power.cpp
+++ b/src/power.cpp
@@ -143,6 +143,13 @@ void AXP192_init(void) {
     pmu.clearIRQ();
 #endif // PMU_INT
 
+// set charging parameterss according to user settings if we have (see power.h)
+#ifdef PMU_CHARGE_CURRENT
+    pmu.setChargeControlCur(PMU_CHARGE_CURRENT);
+    pmu.setChargingTargetVoltage(PMU_CHARGE_CUTOFF);
+    pmu.enableChargeing(true);
+#endif
+
     ESP_LOGI(TAG, "AXP192 PMU initialized");
   }
 }
@@ -292,6 +299,20 @@ uint8_t IP5306_GetBatteryLevel(void) {
   return IP5306_LEDS2PCT(state);
 }
 
+void IP5306_SetChargerEnabled(uint8_t v) {
+  ip5306_set_bits(IP5306_REG_SYS_0, 4, 1, v); // 0:dis,*1:en
+}
+
+void IP5306_SetChargeCutoffVoltage(uint8_t v) {
+  ip5306_set_bits(IP5306_REG_CHG_2, 2, 2,
+                  v); //*0:4.2V, 1:4.3V, 2:4.35V, 3:4.4V
+}
+
+void IP5306_SetEndChargeCurrentDetection(uint8_t v) {
+  ip5306_set_bits(IP5306_REG_CHG_1, 6, 2,
+                  v); // 0:200mA, 1:400mA, *2:500mA, 3:600mA
+}
+
 void printIP5306Stats(void) {
   bool usb = IP5306_GetPowerSource();
   bool full = IP5306_GetBatteryFull();
@@ -302,4 +323,10 @@ void printIP5306Stats(void) {
            full ? "CHARGED" : (usb ? "CHARGING" : "DISCHARGING"), level);
 }
 
+void IP5306_init(void) {
+  IP5306_SetChargerEnabled(1);
+  IP5306_SetChargeCutoffVoltage(PMU_CHG_CUTOFF);
+  IP5306_SetEndChargeCurrentDetection(PMU_CHG_CURRENT);
+}
+
 #endif // HAS_IP5306
\ No newline at end of file
diff --git a/src/sdcard.cpp b/src/sdcard.cpp
index 5faab5cd..5047ee2e 100644
--- a/src/sdcard.cpp
+++ b/src/sdcard.cpp
@@ -1,25 +1,34 @@
 // routines for writing data to an SD-card, if present
 
-#if (HAS_SDCARD)
-
 // Local logging tag
 static const char TAG[] = __FILE__;
 
 #include "sdcard.h"
 
-static bool useSDCard;
+#ifdef HAS_SDCARD
 
-static void createFile(void);
+static bool useSDCard;
 
 File fileSDCard;
 
 bool sdcard_init() {
-  ESP_LOGD(TAG, "looking for SD-card...");
+  ESP_LOGI(TAG, "looking for SD-card...");
+
+  // for usage of SD drivers on ESP32 platform see
+  // https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/sdspi_host.html
+  // https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/sdmmc_host.html
+
+#if HAS_SDCARD == 1 // use SD SPI host driver
   useSDCard = SD.begin(SDCARD_CS, SDCARD_MOSI, SDCARD_MISO, SDCARD_SCLK);
-  if (useSDCard)
+#elif HAS_SDCARD == 2 // use SD MMC host driver
+  useSDCard = SD_MMC.begin();
+#endif
+
+  if (useSDCard) {
+    ESP_LOGI(TAG, "SD-card found");
     createFile();
-  else
-    ESP_LOGD(TAG, "SD-card not found");
+  } else
+    ESP_LOGI(TAG, "SD-card not found");
   return useSDCard;
 }
 
@@ -63,11 +72,23 @@ void createFile(void) {
 
   for (int i = 0; i < 100; i++) {
     sprintf(bufferFilename, SDCARD_FILE_NAME, i);
-    ESP_LOGD(TAG, "SD: looking for file <%s>", bufferFilename);
+    // ESP_LOGD(TAG, "SD: looking for file <%s>", bufferFilename);
+
+#if HAS_SDCARD == 1
     bool fileExists = SD.exists(bufferFilename);
+#elif HAS_SDCARD == 2
+    bool fileExists = SD_MMC.exists(bufferFilename);
+#endif
+
     if (!fileExists) {
-      ESP_LOGD(TAG, "SD: file does not exist: opening");
+      // ESP_LOGD(TAG, "SD: file does not exist: opening");
+
+#if HAS_SDCARD == 1
       fileSDCard = SD.open(bufferFilename, FILE_WRITE);
+#elif HAS_SDCARD == 2
+      fileSDCard = SD_MMC.open(bufferFilename, FILE_WRITE);
+#endif
+
       if (fileSDCard) {
         ESP_LOGD(TAG, "SD: name opened: <%s>", bufferFilename);
         fileSDCard.print(SDCARD_FILE_HEADER);
diff --git a/src/senddata.cpp b/src/senddata.cpp
index 07de525a..d6067131 100644
--- a/src/senddata.cpp
+++ b/src/senddata.cpp
@@ -50,6 +50,9 @@ void SendPayload(uint8_t port, sendprio_t prio) {
 #ifdef HAS_SPI
   spi_enqueuedata(&SendBuffer);
 #endif
+#ifdef HAS_MQTT
+  mqtt_enqueuedata(&SendBuffer);
+#endif
 
 // write data to sdcard, if present
 #ifdef HAS_SDCARD
@@ -179,4 +182,7 @@ void flushQueues() {
 #ifdef HAS_SPI
   spi_queuereset();
 #endif
+#ifdef HAS_MQTT
+  mqtt_queuereset();
+#endif
 }
diff --git a/src/timekeeper.cpp b/src/timekeeper.cpp
index 6d8439ec..87ef0ad0 100644
--- a/src/timekeeper.cpp
+++ b/src/timekeeper.cpp
@@ -1,5 +1,6 @@
 #include "timekeeper.h"
 
+/*
 #if !(HAS_LORA)
 #if (TIME_SYNC_LORASERVER)
 #error TIME_SYNC_LORASERVER defined, but device has no LORA configured
@@ -7,6 +8,7 @@
 #error TIME_SYNC_LORAWAN defined, but device has no LORA configured
 #endif
 #endif
+*/
 
 // Local logging tag
 static const char TAG[] = __FILE__;