Paradigm Electronics is exploring the exciting new field of cheap Wireless devices.

See this page which explains the fundamentals of protocols and setup for IOT devices. IOT Setup information, and all 'Suppliers links' and have been recently confirmed, and updated.

See this page for an example IOT device that monitors a switch and generates an MQTT message. IOT SWITCH Example,

'Internet of Things' Suppliers SUPPLIERS.



This projects on this page use 'USB interfaces' to connect and program various ESP8266 devices,
and now has to be updated to utilize one of the only currently supported USB Interface.

I currently use only "Windows 10" for development, as it is the only 'fully supported
Windows operating system'. The problem does not seem to exist for the older Windows 7.

Over several years Microsoft has progressively removed support in 'Windows 10'
for many Device Drivers supporting USB interface devices.

The reason suggested is that it is to remove support for counterfeited chips that
are being sold by China, and are affecting the local IC production Industry.

Whereas many of the USB Interface devices I used had been purchased from China on ebay, at very
low prices , many others that I also have purchased, were from reputable local suppliers, -
and those have also stopped working.


The above image shows the Dark Blue (or Black) Prolific and the Red FTDI USB Serial Adapters.

The first ones to vanish from Windows 10 were the the 'Prolific CP2102' family, and
a few months ago the red 'FTDI family' stopped working completely.
However, a later Windows 10 release seems to have fixed this.
Several other USB TTL interfaces also appear to have stopped functioning.

Choosing a new USB Serial Adapter

Finding all of the Prolific and FTDI devices rejected,
I checked my stock and found a small number of 'Baite'
USB serial interface devices that appeared to work.
However when set to 3.3V - still fed 5 volts out on the
serial port. I suspect I may have 'cooked' one of
my ESP01 modules.


See this warning article -
Instructable "USB-to-Serial-Convertor-for-ESP8266"

and this youtube Video "When 3.3v isn't actually 3.3v: USB to Serial adapters"


The only working USB Serial Adapter that I now have is the 'Freetronics' - so I will
adjust all my circuits and diagrams to use this adapter - over the next few weeks.


The Freetronics USB-Serial Adapter:

... Freetronics-USB-Serial-small.jpg

Interface Pins are:
  • CTS
  • RX
  • TX
  • VOUT
  • nc
  • GND




Paradigm Electronics has been designing, developing, and programming PIC Microcontroller circuits for small projects for over sixteen years now, and ESP8266 is an exciting new field.

Creating an ESP8266 MQTT SENDER:

This section will explain how to wire up and program an "ESP8266" module with an "DHT11 Sensor (Digital Temperature and Humidity Sensor)". There are several different varieties of DHT Sensors - all usually have a sheet showing the pinout.
The small blue one that I use has the following pinout (viewed from the front).
  • Pin 1. VDD
  • Pin 2. DATA
  • Pin 3. Null (no connection)
  • Pin 4. GND
  • Wire up the ESP8266 module with DHT11 Sensor as per the following drawing....
  • Be very careful about the power supply to ensure the ESP-12 does not exceed 3.3Volt....
  • But remember, if using a modular Power Supply module that these need 8-12 Volt input...

  • The above Breadboard has been updated to Inset the missing wire between the Regulator and circuits.
  • Run the Arduino IDE and open a new 'Sketch' which contains some suggested code.
  • Select and Copy the all text from the following window.
  • Paste all the text (overwriting the new 'Sketch' suggestions).
  • Update the 'WIFINAME', 'PASSWORD' and 'mqtt_server' with your values.
  • If you Network uses an Address other the enter IPADDRESS and ROUTER_ADDRESS.
  • 'File => Save As' the Sketch 'ESP8266_DHT_hallway_197' .
  • (The naming convention includes the location 'hallway' and the IP address '197'.)
  • Ensure that the Tools => Board: is set to 'Generic ESP8266 Module'
  • 'Verify / Compile' the Sketch.
  • Place a jumper between GPIO0 and GROUND.
  • Press the Reset button and 'Upload' the Sketch.
  • Remove the programming jumper and press the Reset button again.
  • Create the other ESP8266 boards and load 'ESP8266_XXX_19X' etc.
  • This is the Scematic for the above ESP8266 wiring...
  • Schematic

Creating an ESP01 PCB Version of the MQTT SENDER:

This section will explain how to create and program an "ESP01" module with a "DHT11 Sensor", and an external sensor input - that can be connected to a PIR Motion Detector.




  • Note - This module is designed run from a 5volt plugpack....
  • It can also be powered from batteries (4 x AA cells) using a three pin connector....
  • The three pin connector is wired with +6v on the Middle pin and GROUND on both outside pins...
  • This ensures that it cannot be plugged in the wrong way.

Connections for new ESP01 PCB


To program the PCB; a jumper must be placed across the 'Flash' connector and the RESET button (just beside the jumper) must be pressed.


The USB FTTDI Adapter provides the connection to the programming computer.


The three wires plugged into the board (just behind the Regulator IC), are for the connection to the HC-SR501 PIR detector.

They are:
  • RED (Plus 5volt)
  • BROWN (PIR output)
  • BLACK (Ground)



  • This is the new PCB for the above ESP01 wiring...
  • PCB
    • The 'Sketch' software for this module has several features to support the HC-SR501 sensor....
    • The ESP01 Arduino IDE 'Sketch' software for this module has been named "ESP01_DHT_Outdoor_PIR_195" ..
    • All messages are returned under the 'outdoor/pir' topic as a decimal number eg: '50.1', '00.9', or '99.9'....
    • Initialization can take up to 60 seconds, before readings can be trusted...
    • ...During this time it will send '50.1', '50.2' etc and will ignore any status until after '50.6'....
    • A High state will be returned as numbers starting with '99.1', '99.2'... increasing every 10 seconds up to '99.9' ...
    • A Low state will be returned as numbers starting with '00.1', '00.2'... increasing every 10 seconds up to '00.9' ...
    • This allows the OpenHAB application to work out how long it should wait for each transition ...

    Software for "ESP01_DHT_outdoor_PIR_195"

    Follow the instructions earlier on this page to load this Arduino 'Sketch'.
    Dont forget to change the "WIFINAME", and "PASSWORD" for your network.

    Last updated: 25-APR-2021 7:21 PM.
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