diff --git a/node-wifi-mqtt/Makefile b/node-wifi-mqtt/Makefile
index d494c56..a44f01d 100644
--- a/node-wifi-mqtt/Makefile
+++ b/node-wifi-mqtt/Makefile
@@ -1,35 +1,15 @@
-# makeEspArduino: A makefile for ESP8266/Arduino projects.
-# https://github.com/plerup/makeEspArduino
+$(eval venvpath  := .venv)
+$(eval python    := $(venvpath)/bin/python)
+$(eval pip       := $(venvpath)/bin/pip)
+$(eval pio       := $(venvpath)/bin/pio)
 
-# Announce path to your "ESP8266 Arduino Core" installation
-# Can also be announced via environment variable: export ESP_ROOT=...
-# ESP_ROOT=~/sdk/esp8266-arduino
 
-# Manually enumerate libraries, this is currently the only deterministic way.
-LIBS = \
-    $(ESP_LIBS)/esp8266 \
-    $(ESP_LIBS)/GDBStub \
-    $(ESP_LIBS)/SD \
-    $(ESP_LIBS)/SPI \
-    $(ESP_LIBS)/Wire \
-    $(ESP_LIBS)/ESP8266WiFi \
-    $(ESP_LIBS)/ESP8266HTTPClient \
-    ../libraries/SerialDebugger/*.h \
-    ../libraries/SerialDebugger/*.cpp \
-    ../libraries/Adafruit_MQTT_Library/*.h \
-    ../libraries/Adafruit_MQTT_Library/*.cpp \
-    ../libraries/ArduinoJson/include \
-    ../libraries/OneWire \
-    ../libraries/DallasTemperature \
-    ../libraries/RobTillaart-Arduino/libraries/DHTstable \
-    ../libraries/RobTillaart-Arduino/libraries/RunningMedian \
-    ../libraries/HX711 \
-    ../libraries/ADS1231
+build: setup-virtualenv
+	$(pio) run
 
-# Run makeEspArduino
-include ../tools/makeEspArduino/makeEspArduino.mk
+upload: setup-virtualenv
+	$(pio) run --target upload --upload-port=${MCU_PORT}
 
-### FWBUILDER_DIR
-### Include helpers from Firmware-Builder directory.
-FWBUILDER_DIR     = ../tools/Firmware-Builder
-include $(FWBUILDER_DIR)/Helper.mk
+setup-virtualenv:
+	@test -e $(python) || `command -v virtualenv` --python=python3 $(venvpath)
+	$(pip) install platformio
diff --git a/node-wifi-mqtt/README.rst b/node-wifi-mqtt/README.rst
index 681dfb7..553c10d 100644
--- a/node-wifi-mqtt/README.rst
+++ b/node-wifi-mqtt/README.rst
@@ -21,6 +21,7 @@ Basic WiFi/MQTT sensor node
 ************
 Introduction
 ************
+
 A beehive monitoring sensor node based on the `Adafruit Feather HUZZAH`_, featuring an ESP8266_ MCU.
 Telemetry data is transmitted using WiFi/MQTT.
 The most recent firmware version is available at `node-wifi-mqtt.ino`_.
@@ -105,33 +106,20 @@ Configure WiFi and MQTT settings::
 
 Build
 =====
-The build system is based on `makeESPArduino`_, a Makefile for ESP8286 Arduino projects.
-
-Setup SDK::
 
-    mkdir ~/sdk; cd ~/sdk
-    git clone https://github.com/esp8266/Arduino esp8266-arduino
-
-    # Download appropriate Espressif SDK
-    cd esp8266-arduino/tools
-    ./get.py
+The build system is based on PlatformIO_.
 
 Build firmware::
 
-    # Announce path to SDK
-    export ESP_ROOT=~/sdk/esp8266-arduino
-
-    # Run Makefile
     make
 
-Enable more verbose output::
-
-    export VERBOSE=true
-
 
 Upload to MCU
 =============
 ::
 
+    export MCU_PORT=/dev/ttyUSB0
     make upload
 
+
+.. _PlatformIO: https://platformio.org/
diff --git a/node-wifi-mqtt/node-wifi-mqtt.ino b/node-wifi-mqtt/node-wifi-mqtt.ino
index f0125e3..afa34e4 100644
--- a/node-wifi-mqtt/node-wifi-mqtt.ino
+++ b/node-wifi-mqtt/node-wifi-mqtt.ino
@@ -29,7 +29,8 @@
               Add comment about connecting GPIO#16 to RST for waking up after deep sleep. Thanks, Giuseppe and Matthias!
               Add sensor ADS1231. Thanks, Clemens!
               Silence debug output by using SerialDebugger to reduce battery drain even more.
-   2021-05-02 Use SerialDebug library by Joao Lopes.
+   2021-05-02 Modernize code by using the SerialDebug library by Joao Lopes and
+              add build environment based on PlatformIO.
 
 
    GNU GPL v3 License
diff --git a/node-wifi-mqtt/platformio.ini b/node-wifi-mqtt/platformio.ini
new file mode 100644
index 0000000..34aef69
--- /dev/null
+++ b/node-wifi-mqtt/platformio.ini
@@ -0,0 +1,30 @@
+; PlatformIO Project Configuration File
+;
+;   Build options: build flags, source filter
+;   Upload options: custom upload port, speed and extra flags
+;   Library options: dependencies, extra library storages
+;   Advanced options: extra scripting
+;
+; Please visit documentation for the other options and examples
+; https://docs.platformio.org/page/projectconf.html
+
+[platformio]
+src_dir = .
+
+[env:huzzah]
+platform = espressif8266
+board = huzzah
+framework = arduino
+
+monitor_speed = 115200
+
+lib_deps =
+    joaolopesf/SerialDebug@^0.9.82
+    OneWire@2.3.5
+    HX711@0.7.4
+    DallasTemperature@3.8.1
+    robtillaart/DHTStable@^0.2.9
+    ../libraries/ADS1231
+    RunningMedian@0.1.15
+    ArduinoJson@^5
+    https://github.com/daq-tools/Adafruit_MQTT_Library#maxbuffersize-2048