B4R Tutorials

Weather Station using MQTT, UDP and Thingspeak

This is my humble effort to produce a weather station (based on this project). You will need:

1 x Wemos D1 Mini
1 x BME280 Sensor
1 x TP4056 Li-Ion Charging board
1 x 3.7V Li-Ion Battery
Last edited:

ESP32 Mesh example

ESP32 Camera Picture Capture and Video Streaming! (Updated with code!)


Last December I made a request for support for the ESP32 Camera support. Well, I finally found the time to work on it myself and here's my initial attempt at implementing this with...
Last edited:

PS4 F1 2020 Interfacing using ESP8266


Hi Guys,

My wife's eldest son is addicted to PS4 F1 2020 game, even bought himself a Rig for a Steering Wheel and Pedals.
He works alongside with me and on one of...
Last edited:

ESP32 - Fix uploading sketch error problem

Temporary solution:
After you start compiling and compiling log reachs uploading sketch stage, you should continuously press BOOT button on ESP32 board until uploading complete...

Check car's lights status and report

Hey everyone,

here is an implementation of a car lights checker which reports if all 4 car's lights are working properly. To find out if there is a problem with the lights (head and rear) we use...
Last edited:

tone() function

Here is a tone function that does Arduino's tone()
The buzzer is connected between pin 6 and ground :
Private Sub AppStart
    Delay( 1000)...
Last edited:

[Electronics] "Wake-up on sensor trigger" and auto power-off

Hi guys,

So B4R is so much more than simply code and breakout boards assembled/connecter by jump-wires and breadboards...
I know for a fact that most of us are not electronics pronned and thus...

Arduino RP2040 is in the block


ESP32: Simple OTA/Update via WebServer

This example (adapted from the Arduino examples under Arduino->File->Examples)

- downloads a file from a server (exactly: the update file)
- store this file to the filesystem (SPIFFS)
- starts an...

ESP32: Download huge file from a server and save it

This example downloads a file from a server folder (here I use a folder in htdocs on my apache server) and saves it to a file on the file system. Tested with 700KB files. Set headers (browse the...

Updated B4R-AES256 example (compatible with B4x, php and all other platforms)

This is an updated example how to en-/decrypt data with AES256.

Libs needed: jRandomAccessFile only


- As far as I know, the ESP32 doesn't support padding like PKCS5/7, so I had to do it...


  • ESP32AES256.zip
    2.3 KB · Views: 68

Erels B4R Oveview from Walt's B4xGoodies - created with B4xgoodies Explorer using BVAD3

BLE Xiaomi Temperature Sensor Project (ESP32 with BLE+WIFI)


My office gets cold overnight in winter. I have a heater which has a basic thermostat but its very inaccurate (its just a min/max dial not temperature based). If I leave it on...


  • ESPXiaomi.zip
    2.3 KB · Views: 110
Last edited:

u-blox ThingStream - Nina W106 - blog

Controlling DSTV decoder from Android device via Nano and HC-05 bluetooth module

Just for the fun of it. Can now control my Digital Satellite TV decoder from anywhere in my house....
Nano connected to the HC-05 module
B4A app connects to the HC-05 and sends the B4A "button...


  • b4aHC-05.zip
    31.2 KB · Views: 115
  • b4rHC05.zip
    2.9 KB · Views: 113

LCD Clock example

Arduino Uno with LCD shield:


Working with a LCD monitor:
1. Initialize the LiquidCrystal object and set the connected...


  • B4J_SerialConnector.zip
    4.1 KB · Views: 535
  • B4R_LCD.zip
    987 bytes · Views: 697

ESP Configurator based on B4RSerializator


This tool replaces the browser based solution...


  • B4R_ESPConfigurator.zip
    2 KB · Views: 1,802
  • B4J_ESPConfigurator.zip
    46.1 KB · Views: 1,551

Use Rasberry Pi Pico with the Arduino IDE and thus with B4R


ESP32 Now with encryption, master and automatically added slaves

Here's an advanced ESP32 Now example. The Inlince C code is from several sources (see the inline remarks).

Note: Sometimes there are issues with the Wifi channel (WiFi and ESP Now must use the...


  • B4JReceiver.zip
    4 KB · Views: 74
  • ESPNowTwoMaster.zip
    3.2 KB · Views: 85
  • ESPNowTwoWaySlave.zip
    2.5 KB · Views: 91