diff --git a/lib/AmsConfiguration/include/AmsConfiguration.h b/lib/AmsConfiguration/include/AmsConfiguration.h
index 3f8cfa1c..7acbd349 100644
--- a/lib/AmsConfiguration/include/AmsConfiguration.h
+++ b/lib/AmsConfiguration/include/AmsConfiguration.h
@@ -4,7 +4,7 @@
 #include "Arduino.h"
 
 #define EEPROM_SIZE 1024*3
-#define EEPROM_CHECK_SUM 102 // Used to check if config is stored. Change if structure changes
+#define EEPROM_CHECK_SUM 103 // Used to check if config is stored. Change if structure changes
 #define EEPROM_CLEARED_INDICATOR 0xFC
 #define EEPROM_CONFIG_ADDRESS 0
 #define EEPROM_TEMP_CONFIG_ADDRESS 2048
@@ -142,7 +142,8 @@ struct GpioConfig {
 	uint8_t vccBootLimit;
 	uint16_t vccResistorGnd;
 	uint16_t vccResistorVcc;
-}; // 20
+	bool hanPinPullup;
+}; // 21
 
 struct DomoticzConfig {
 	uint16_t elidx;
@@ -314,6 +315,7 @@ private:
 	bool relocateConfig96(); // 2.1.14
 	bool relocateConfig100(); // 2.2-dev
 	bool relocateConfig101(); // 2.2.0 through 2.2.8
+	bool relocateConfig102(); // 2.2.9
 
 	void saveToFs();
 	bool loadFromFs(uint8_t version);
diff --git a/lib/AmsConfiguration/src/AmsConfiguration.cpp b/lib/AmsConfiguration/src/AmsConfiguration.cpp
index 22996b35..cbf69fd6 100644
--- a/lib/AmsConfiguration/src/AmsConfiguration.cpp
+++ b/lib/AmsConfiguration/src/AmsConfiguration.cpp
@@ -406,6 +406,7 @@ bool AmsConfiguration::setGpioConfig(GpioConfig& config) {
 	GpioConfig existing;
 	if(getGpioConfig(existing)) {
 		meterChanged |= config.hanPin != existing.hanPin;
+		meterChanged |= config.hanPinPullup != existing.hanPinPullup;
 	}
 	/* This currently does not work, as it checks its own pin
 	if(pinUsed(config.hanPin, config)) {
@@ -457,6 +458,7 @@ bool AmsConfiguration::setGpioConfig(GpioConfig& config) {
 
 void AmsConfiguration::clearGpio(GpioConfig& config) {
 	config.hanPin = 3;
+	config.hanPinPullup = true;
 	config.apPin = 0xFF;
 	config.ledPin = 0xFF;
 	config.ledInverted = true;
@@ -796,6 +798,14 @@ bool AmsConfiguration::hasConfig() {
 					configVersion = 0;
 					return false;
 				}
+			case 102:
+				configVersion = -1; // Prevent loop
+				if(relocateConfig102()) {
+					configVersion = 103;
+				} else {
+					configVersion = 0;
+					return false;
+				}
 			case EEPROM_CHECK_SUM:
 				return true;
 			default:
@@ -1017,6 +1027,20 @@ bool AmsConfiguration::relocateConfig101() {
 	return ret;
 }
 
+bool AmsConfiguration::relocateConfig102() {
+	EEPROM.begin(EEPROM_SIZE);
+
+	GpioConfig gpioConfig;
+	EEPROM.get(CONFIG_GPIO_START, gpioConfig);
+	gpioConfig.hanPinPullup = true;
+	EEPROM.put(CONFIG_GPIO_START, gpioConfig);
+
+	EEPROM.put(EEPROM_CONFIG_ADDRESS, 103);
+	bool ret = EEPROM.commit();
+	EEPROM.end();
+	return ret;
+}
+
 bool AmsConfiguration::save() {
 	EEPROM.begin(EEPROM_SIZE);
 	EEPROM.put(EEPROM_CONFIG_ADDRESS, EEPROM_CHECK_SUM);
@@ -1171,6 +1195,7 @@ void AmsConfiguration::print(Print* debugger)
 	if(getGpioConfig(gpio)) {
 		debugger->println("--GPIO configuration--");
 		debugger->printf("HAN pin:              %i\r\n", gpio.hanPin);
+		debugger->printf("HAN pin pullup        %s\r\n", gpio.hanPinPullup ? "Yes" : "No");
 		debugger->printf("LED pin:              %i\r\n", gpio.ledPin);
 		debugger->printf("LED inverted:         %s\r\n", gpio.ledInverted ? "Yes" : "No");
 		debugger->printf("LED red pin:          %i\r\n", gpio.ledPinRed);
diff --git a/lib/SvelteUi/app/src/lib/BoardTypeSelectOptions.svelte b/lib/SvelteUi/app/src/lib/BoardTypeSelectOptions.svelte
index 6fefe749..ca77d508 100644
--- a/lib/SvelteUi/app/src/lib/BoardTypeSelectOptions.svelte
+++ b/lib/SvelteUi/app/src/lib/BoardTypeSelectOptions.svelte
@@ -42,6 +42,9 @@
     </optgroup>
 {/if}
 {#if chip == 'esp32c3'}
+    <optgroup label="Custom hardware">
+        <option value={8}>{boardtype(chip, 8)}</option>
+    </optgroup>
     <optgroup label="Generic hardware">
         <option value={71}>{boardtype(chip, 71)}</option>
         <option value={70}>{boardtype(chip, 70)}</option>
diff --git a/lib/SvelteUi/app/src/lib/ConfigurationPanel.svelte b/lib/SvelteUi/app/src/lib/ConfigurationPanel.svelte
index 67142a6e..eb209915 100644
--- a/lib/SvelteUi/app/src/lib/ConfigurationPanel.svelte
+++ b/lib/SvelteUi/app/src/lib/ConfigurationPanel.svelte
@@ -88,7 +88,8 @@
             i: 0, e: 0, v: 0, a: 0, r: 0, c: 0, t: 0, p: 0, d: 0, m: 0, s: 0
         },
         i: {
-            h: null, a: null,
+            h: { p: null, u: true },
+            a: null,
             l: { p: null, i: false },
             r: { r: null, g: null, b: null, i: false },
             t: { d: null, a: null },
@@ -599,8 +600,8 @@
             <input type="hidden" name="i" value="true"/>
             <div class="flex flex-wrap">
                 <div class="w-1/3">
-                    HAN<br/>
-                    <select name="ih" bind:value={configuration.i.h} class="in-f w-full">
+                    HAN<label class="ml-2"><input name="ihu" value="true" bind:checked={configuration.i.h.u} type="checkbox" class="rounded mb-1"/> pullup</label><br/>
+                    <select name="ihp" bind:value={configuration.i.h.p} class="in-f w-full">
                         <UartSelectOptions chip={sysinfo.chip}/>
                     </select>
                 </div>
diff --git a/lib/SvelteUi/app/src/lib/Helpers.js b/lib/SvelteUi/app/src/lib/Helpers.js
index af66697d..dbda0b0c 100644
--- a/lib/SvelteUi/app/src/lib/Helpers.js
+++ b/lib/SvelteUi/app/src/lib/Helpers.js
@@ -87,6 +87,8 @@ export function boardtype(c, b) {
             return "Custom hardware by Roar Fredriksen";
         case 1:
             return "Kamstrup module by Egil Opsahl";
+        case 8:
+            return "µHAN mosquito by dbeinder"
         case 3:
             return "Pow-K (UART0)";
         case 4:
diff --git a/lib/SvelteUi/app/src/lib/UartSelectOptions.svelte b/lib/SvelteUi/app/src/lib/UartSelectOptions.svelte
index 29bf47e1..3b2897f5 100644
--- a/lib/SvelteUi/app/src/lib/UartSelectOptions.svelte
+++ b/lib/SvelteUi/app/src/lib/UartSelectOptions.svelte
@@ -1,13 +1,21 @@
 <script>
     export let chip;
 
-    let gpioMax = 44;
+    let gpioMax = 39;
     $: {
-        gpioMax = chip == 'esp8266' ? 16 : chip == 'esp32s2' ? 44 : 39;
+        switch (chip) {
+            case 'esp8266': gpioMax = 16; break;
+            case 'esp32s2': gpioMax = 44; break;
+            case 'esp32c3': gpioMax = 19; break;
+        }
     }
 </script>
 
+{#if chip == 'esp32c3'}
+<option value={20}>UART0</option>
+{:else}
 <option value={3}>UART0</option>
+{/if}
 {#if chip == 'esp8266'}
 <option value={113}>UART2</option>
 {/if}
diff --git a/lib/SvelteUi/json/conf_gpio.json b/lib/SvelteUi/json/conf_gpio.json
index c887d2f3..6a0bc0e9 100644
--- a/lib/SvelteUi/json/conf_gpio.json
+++ b/lib/SvelteUi/json/conf_gpio.json
@@ -1,5 +1,8 @@
 "i": {
-    "h": %s,
+    "h": { 
+        "p": %s,
+        "u": %s
+    },
     "a": %s,
     "l": {
         "p": %s,
diff --git a/lib/SvelteUi/src/AmsWebServer.cpp b/lib/SvelteUi/src/AmsWebServer.cpp
index 0c1f1a7d..84636d52 100644
--- a/lib/SvelteUi/src/AmsWebServer.cpp
+++ b/lib/SvelteUi/src/AmsWebServer.cpp
@@ -913,6 +913,7 @@ void AmsWebServer::configurationJson() {
 	server.sendContent(buf);
 	snprintf_P(buf, BufferSize, CONF_GPIO_JSON,
 		gpioConfig->hanPin == 0xff ? "null" : String(gpioConfig->hanPin, 10).c_str(),
+		gpioConfig->hanPinPullup ? "true" : "false",
 		gpioConfig->apPin == 0xff ? "null" : String(gpioConfig->apPin, 10).c_str(),
 		gpioConfig->ledPin == 0xff ? "null" : String(gpioConfig->ledPin, 10).c_str(),
 		gpioConfig->ledInverted ? "true" : "false",
@@ -1001,6 +1002,15 @@ void AmsWebServer::handleSave() {
 			}
 		#elif defined(CONFIG_IDF_TARGET_ESP32C3)
 			switch(boardType) {
+				case 8: // dbeinder: HAN mosquito
+					gpioConfig->hanPin = 7;
+					gpioConfig->hanPinPullup = false;
+					gpioConfig->apPin = 9;
+					gpioConfig->ledRgbInverted = true;
+					gpioConfig->ledPinRed = 5;
+					gpioConfig->ledPinGreen = 6;
+					gpioConfig->ledPinBlue = 4;
+					break;
 				case 71: // ESP32-C3-DevKitM-1
 					gpioConfig->apPin = 9;
 				case 70: // Generic ESP32-C3
@@ -1137,6 +1147,7 @@ void AmsWebServer::handleSave() {
 				meterConfig->baud = 2400;
 				meterConfig->parity = 3; // 8N1
 			case 2: // spenceme
+			case 8: // dbeinder: HAN mosquito
 			case 50: // Generic ESP32-S2
 			case 51: // Wemos S2 mini
 			case 70: // Generic ESP32-C3
@@ -1329,7 +1340,8 @@ void AmsWebServer::handleSave() {
 
 	if(server.hasArg(F("i")) && server.arg(F("i")) == F("true")) {
 		if(debugger->isActive(RemoteDebug::DEBUG)) debugger->printf(PSTR("Received GPIO config"));
-		gpioConfig->hanPin = server.hasArg(F("ih")) && !server.arg(F("ih")).isEmpty() ? server.arg(F("ih")).toInt() : 3;
+		gpioConfig->hanPin = server.hasArg(F("ihp")) && !server.arg(F("ihp")).isEmpty() ? server.arg(F("ihp")).toInt() : 3;
+		gpioConfig->hanPinPullup = server.hasArg(F("ihu")) && server.arg(F("ihu")) == F("true");
 		gpioConfig->ledPin = server.hasArg(F("ilp")) && !server.arg(F("ilp")).isEmpty() ? server.arg(F("ilp")).toInt() : 0xFF;
 		gpioConfig->ledInverted = server.hasArg(F("ili")) && server.arg(F("ili")) == F("true");
 		gpioConfig->ledPinRed = server.hasArg(F("irr")) && !server.arg(F("irr")).isEmpty() ? server.arg(F("irr")).toInt() : 0xFF;
@@ -1996,6 +2008,7 @@ void AmsWebServer::configFileDownload() {
 		GpioConfig gpio;
 		config->getGpioConfig(gpio);
 		if(gpio.hanPin != 0xFF) server.sendContent(buf, snprintf_P(buf, BufferSize, PSTR("gpioHanPin %d\n"), gpio.hanPin));
+		if(gpio.hanPin != 0xFF) server.sendContent(buf, snprintf_P(buf, BufferSize, PSTR("gpioHanPinPullup %d\n"), gpio.hanPinPullup ? 1 : 0));
 		if(gpio.apPin != 0xFF) server.sendContent(buf, snprintf_P(buf, BufferSize, PSTR("gpioApPin %d\n"), gpio.apPin));
 		if(gpio.ledPin != 0xFF) server.sendContent(buf, snprintf_P(buf, BufferSize, PSTR("gpioLedPin %d\n"), gpio.ledPin));
 		if(gpio.ledPin != 0xFF) server.sendContent(buf, snprintf_P(buf, BufferSize, PSTR("gpioLedInverted %d\n"), gpio.ledInverted ? 1 : 0));
diff --git a/src/AmsToMqttBridge.ino b/src/AmsToMqttBridge.ino
index 3e618c69..85f3cdab 100644
--- a/src/AmsToMqttBridge.ino
+++ b/src/AmsToMqttBridge.ino
@@ -564,7 +564,7 @@ void loop() {
 
 	if(config.isMeterChanged()) {
 		config.getMeterConfig(meterConfig);
-		setupHanPort(gpioConfig.hanPin, meterConfig.baud, meterConfig.parity, meterConfig.invert);
+		setupHanPort(gpioConfig, meterConfig.baud, meterConfig.parity, meterConfig.invert);
 		config.ackMeterChanged();
 		delete gcmParser;
 		gcmParser = NULL;
@@ -607,7 +607,7 @@ void loop() {
 				meterAutoIndex++; // Default is to try the first one in setup()
 				debugI("Meter serial autodetect, swapping to: %d, %d, %s", bauds[meterAutoIndex], parities[meterAutoIndex], inverts[meterAutoIndex] ? "true" : "false");
 				if(meterAutoIndex >= 4) meterAutoIndex = 0;
-				setupHanPort(gpioConfig.hanPin, bauds[meterAutoIndex], parities[meterAutoIndex], inverts[meterAutoIndex]);
+				setupHanPort(gpioConfig, bauds[meterAutoIndex], parities[meterAutoIndex], inverts[meterAutoIndex]);
 				meterAutodetectLastChange = now;
 			}
 		} else if(meterAutodetect) {
@@ -617,7 +617,7 @@ void loop() {
 			meterConfig.parity = parities[meterAutoIndex];
 			meterConfig.invert = inverts[meterAutoIndex];
 			config.setMeterConfig(meterConfig);
-			setupHanPort(gpioConfig.hanPin, meterConfig.baud, meterConfig.parity, meterConfig.invert);
+			setupHanPort(gpioConfig, meterConfig.baud, meterConfig.parity, meterConfig.invert);
 		}
 	} catch(const std::exception& e) {
 		debugE("Exception in meter autodetect (%s)", e.what());
@@ -632,7 +632,9 @@ void loop() {
 	#endif
 }
 
-void setupHanPort(uint8_t pin, uint32_t baud, uint8_t parityOrdinal, bool invert) {
+void setupHanPort(GpioConfig& gpioConfig, uint32_t baud, uint8_t parityOrdinal, bool invert) {
+	uint8_t pin = gpioConfig.hanPin;
+
 	if(Debug.isActive(RemoteDebug::INFO)) Debug.printf((char*) F("(setupHanPort) Setting up HAN on pin %d with baud %d and parity %d\n"), pin, baud, parityOrdinal);
 
 	if(baud == 0) {
@@ -644,6 +646,14 @@ void setupHanPort(uint8_t pin, uint32_t baud, uint8_t parityOrdinal, bool invert
 		parityOrdinal = 3; // 8N1
 	}
 
+	SystemConfig sys;
+	config.getSystemConfig(sys);
+	switch(sys.boardType) {
+		case 8: // HAN mosquito: has inverting level shifter
+			invert = !invert;
+			break;
+	}
+
 	HardwareSerial *hwSerial = NULL;
 	if(pin == 3 || pin == 113) {
 		hwSerial = &Serial;
@@ -743,6 +753,11 @@ void setupHanPort(uint8_t pin, uint32_t baud, uint8_t parityOrdinal, bool invert
 		Serial.begin(115200);
 	}
 
+	// The library automatically sets the pullup in Serial.begin()
+	if(!gpioConfig.hanPinPullup) {
+		pinMode(gpioConfig.hanPin, INPUT);
+	}
+
 	// Empty buffer before starting
 	while (hanSerial->available() > 0) {
 		hanSerial->read();
@@ -1621,6 +1636,9 @@ void configFileParse() {
 		} else if(strncmp_P(buf, PSTR("gpioHanPin "), 11) == 0) {
 			if(!lGpio) { config.getGpioConfig(gpio); lGpio = true; };
 			gpio.hanPin = String(buf+11).toInt();
+		} else if(strncmp_P(buf, PSTR("gpioHanPinPullup "), 17) == 0) {
+			if(!lGpio) { config.getGpioConfig(gpio); lGpio = true; };
+			gpio.hanPinPullup = String(buf+17).toInt() == 1;
 		} else if(strncmp_P(buf, PSTR("gpioApPin "), 10) == 0) {
 			if(!lGpio) { config.getGpioConfig(gpio); lGpio = true; };
 			gpio.apPin = String(buf+10).toInt();