Category Archives: ESP8266

IoTBox: Instructions for use

When power is applied to the IoTBox, it will try to connect to the stored WiFi access point and will show the IP address on the screen if successful. The screen will show an error message if it cannot connect.

The IoTBox uses two WiFi modes simultaneously:

  1. Client Mode = It will connect to an Access Point.
  2. Access Point Mode = It will behave as an Access Point.

To configure the IoTBox, look for an open network with the same ID as shown on the OLED display, it will be similar to “iotbox00fcf9ab”.

IoTBox MenuWhen connected, your PC/Mac or Phone will have an address of and the IoTBox menu will be found at

The first thing to do is to upgrade to the latest version of the WiFi SettingsIoTBox firmware. For this, you will need to be connected to an external Access Point chosen on the WiFi settings page and then select OTA Upgrade. The IoTBox will download the updated firmware and then reboot into the new version.

The ESP8266 on the IoTBox is configured as two slots. The OTA firmware is downloaded and stored in the other slot. If it has downloaded correctly, it will reboot into the other slot. You may switch back to the old versiion by using the Switch ROM menu option.

If you have configured something that is causing an issue with the IoTBox, you can reset it using the button (wired to GPIO0). The button on the IoTBox has three functions:

  1. If the button is held down while powering on, you can update the firmware on the chip with a programmer. This is only required when putting the initial firmware on the chip.
  2. If the button is pressed for more than 0.5 seconds and less than 10 seconds (2 seconds is ideal), a message is sent to the button MQTT topic.
  3. If the button is pressed for more than 10 seconds, the settings are cleared to the default values. You will need to set the WiFi and MQTT parameters again.


MQTT Topics

IoTBox has an MQTT v3.1 client built into the firmware and is the main way of communicating to other systems. When MQTT is enabled, it will try to connect every 10 seconds and when successful, it will post “online’ to the LWT topic.MQTT Menu

The following topics are supported:

Note: MQTT can use wildcards, such as ‘+’. This means that a subscription to ‘+/out/led/1’ will pick up data for ‘iotbox00112233/out/led/1’ and ‘iotbox56229922/out/led/1’. This is useful when sending  the same information to many devices.

LED: For the example shown above, the IoTBox is listening on:

  • +/out/led/1
  • +/out/led/2
  • +/out/led/3

A payload of ‘0’ or ‘1’  to these topics switches the LED colour (red, green or blue) off or on. This will likely change in the future to support PWM and a single Topic.

DISPLAY: For the example shown above, the IoTBox is listening on:

  • +/out/display/0
  • +/out/display/1
  • +/out/display/2
  • +/out/display/3
  • +/out/display/4

A payload of upto 20 characters will be displayed on lines 3-8 on the OLED screen. Useful for notifications and information.

BUTTON: A button press creates a payload of ‘1’ on the Topic.

TEMPERATURE: Readings from the sensor (DS18B20 or DHT22) are sent every 10 seconds to this topic.

HUMIDITY: Readings from a DHT22 (if connected) are sent every 10 seconds).

LAST WILL & TESTAMENT: When the IoTBox is connected to MQTT, a payload of ‘online’ is sent to this Topic. The MQTT server will send ‘offline’ if it does not receive a heartbeat from IoTBox.

The best way of exploring how IoTBox uses these Topics is to use the MQTT-SPY application found at MQTT-SPY Homepage.

IoTBox Pinouts and Firmware loading

Here are the pinouts that are defined in the firmware for the IoTBox based on the ESP12 adapter board shown below. It is possible to solder directly to the ESP chip if space is tight but you will need to take into account the various pull ups (eg CH_PD) if you do so.

espadapterIn order to do the initial programming and testing of the module, install the VCC, GND, GPIO0 cables and pins for TX and RX. If you are using a larger box, you may use jumper pins for all of the connections.

Pin NodeMCU IoTBox use Future Use
tx tx on programmer  Additional I/O
rx rx on programmer  Additional I/O
gpio4 D2 to I2C – SCL screen (GPIO4 is sometimes mislabelled labelled as GPIO5 on breakout board!!!)
gpio5 D1 n/c PIR, Vibration
gnd 0 volts
gpio15 D8 resistor 150 ohm to led = RED
gpio2 D4 data pin for 1-wire ds18b20 (or dht22 with 10k resistor to vcc)
gpio0 D3 push to make switch (optional:held high via 10k resistor?). Other side of switch is at GND
gpio14 D5 to I2C – SDA screen
gpio12 D6 resistor 150 ohm to led = BLUE
gpio13 D7 resistor 150 ohm to led = GREEN
vcc 3.3 volts (NOT 5v!)
gpio16 D0 n/c Wake
ch_pd n/c (held high on the breakout board)
adc A0 n/c Potentiometer / Light detection
reset n/c

(Corrected Pins for the colours Blue and Green)

You will need to do an initial flash of the IoTBox chip which will then allow you to do the upgrades from the built in menu. Connect a 3.3v USB FTDI programmer to TX/RX and GND. Connect GPIO0 to GND and then power up the module from a source that supports around 300ma (do not power from the FTDI module).
Here is the commandline to flash the esp8266, (please remember that the esp8266 is 3.3v only – the 5v usb interfaces will kill it!)

(All on one line, may need python2.7 installed for esptool.exe. My USB programmer is using COM2)

esptool.exe -p com2 -b 115200 write_flash -fs 32m 0x00000 rboot.bin 0x02000 iotbox.bin 0x80000 iotbox.espfs.bin

The required files are here.

However, the esptool.exe requires Python to be installed on yourWindows PC – this can cause issues. An alternative ESP8266 flasher is here:

Screen Shot 2015-10-02 at 22.46.07

IoTBox Videos

I have uploaded a couple of videos to describe the function of the IoTBox (while I am waiting for components from China to do the build videos!)

A run though of the web interface menu system:

The IoTBox in operation: 

IoTBox Hardware

Here is the final parts list for the IoTBox. Each item links to the version that I used. They may link to multipacks (I built 30-35 IoTBoxes) but you only need 1 unless noted.

2015-06-28 14.38.24
The final IoTBox

During the beta testing I have tried and killed many boxes and components to get this far. Hopefully it will save you some time and expense. Note that many items came via China to reduce the unit price.

Parts List Continue reading IoTBox Hardware

IoTBox. First steps…

“I want one! – actually can I have 30?”

I took my idea to a few people – the inventors of NodeRed and a couple of members of the team and they thought that the idea was sound – produce a simple IoTBox that we can use in demonstrations to show how connected devices can make use of our products. I was then asked “Can we have 30 ready in a few weeks?”. I had better work fast!.

Continue reading IoTBox. First steps…

IoTBox – an Internet of Things, thingy.

The final version of the IoTBox

2015-06-28 14.38.19
The final version

The IoTBox is a small 5x5cm device with an OLED screen that displays MQTT messages, an RGB LED to show MQTT messages as a status colour, a button that triggers an MQTT message and a waterproof temperature sensor that sends MQTT messages and/or a REST call. It can be updated “OTA” and is powered by the USB connector.

These articles will show you how to build one.

Background to IoTBox

Back in December 2014, I started to look at a new Wifi chip that had just been released as a means of Internet enabling various Arduino projects that I had been thinking about. I soon realised that this processor (the ESP8266) was actual more powerful than the Arduino and much much cheaper.

Continue reading IoTBox – an Internet of Things, thingy.