diff --git a/examples/device-dashboard/net.c b/examples/device-dashboard/net.c
index 0b0ddd76..9f07d8d9 100644
--- a/examples/device-dashboard/net.c
+++ b/examples/device-dashboard/net.c
@@ -113,7 +113,7 @@ static void mqtt_fn(struct mg_connection *c, int ev, void *ev_data, void *fnd) {
 static void timer_mqtt_fn(void *param) {
   struct mg_mgr *mgr = (struct mg_mgr *) param;
   if (s_mqtt == NULL) {
-    struct mg_mqtt_opts opts = {};
+    struct mg_mqtt_opts opts = { 0 };
     s_mqtt = mg_mqtt_connect(mgr, s_config.url, &opts, mqtt_fn, NULL);
   }
 }
diff --git a/examples/esp32/device-dashboard/Makefile b/examples/esp32/device-dashboard/Makefile
index cf1021e0..34bb40c9 100644
--- a/examples/esp32/device-dashboard/Makefile
+++ b/examples/esp32/device-dashboard/Makefile
@@ -2,19 +2,37 @@ THISDIR = $(realpath $(CURDIR))
 ROOTDIR = $(realpath $(CURDIR)/../../..)
 DOCKER ?= docker run --rm $(DA) -v $(ROOTDIR):$(ROOTDIR) -w $(THISDIR) espressif/idf
 CMD ?= idf.py build
+PORT ?= /dev/ttyUSB0
 
 all: example
 
 example:
 	true
 
-build: main/main.c Makefile
+build: Makefile $(wildcard main/*)
 	$(DOCKER) $(CMD)
 
-COMPORT ?= /dev/cu.SLAB_USBtoUART
-ESPTOOL ?= esptool.py
 flash:
-	cd build && $(ESPTOOL) --chip esp32 -p $(COMPORT) -b 460800 --before=default_reset --after=hard_reset write_flash --flash_mode dio --flash_freq 40m --flash_size 2MB 0x8000 partition_table/partition-table.bin 0x1000 bootloader/bootloader.bin 0x100000 mongoose-esp32-example.bin
+flash: CMD = idf.py flash
+flash: DA = --device $(PORT)
+flash: build
+
+.PHONY: build
+
+dashboard.hex: build
+	esputil mkhex \
+		0x8000 build/partition_table/partition-table.bin \
+		0x1000 build/bootloader/bootloader.bin \
+		0x100000 build/mongoose-esp32-example.bin > $@
+
+flash2: dashboard.hex
+	esputil -p $(PORT) -b 921600 -fp 0x220 flash dashboard.hex
+	esputil -p $(PORT) monitor
+
+ESPTOOL ?= esptool.py
+
+flash3:
+	cd build && $(ESPTOOL) --chip esp32 -p $(PORT) -b 460800 --before=default_reset --after=hard_reset write_flash --flash_mode dio --flash_freq 40m --flash_size 2MB 0x8000 partition_table/partition-table.bin 0x1000 bootloader/bootloader.bin 0x100000 mongoose-esp32-example.bin
 
 clean:
 	$(DOCKER) rm -rf build sdkconfig
diff --git a/examples/esp32/device-dashboard/README.md b/examples/esp32/device-dashboard/README.md
index eeac9344..82251bf0 100644
--- a/examples/esp32/device-dashboard/README.md
+++ b/examples/esp32/device-dashboard/README.md
@@ -1 +1 @@
-See detailed tutorial at https://mongoose.ws/tutorials/esp32/
+See detailed tutorial at https://mongoose.ws/tutorials/esp32/device-dashboard