B4R Tutorials

Not exactly a tutorial, but still education for those not in the know...

 

This B4R example/library works with DHT11 and DHT22 temperature and humidity sensors:

This inexpensive device (DHT11) allows for measure temperature and humidity:

• Very Low cost
• 3...

 

Hi All,

The attached zip files have the Arduino libraries and the B4R libraries together with a small B4R app showing how to use the Adafruit MPR121 capacitive touch 12 key keypad.

Big thanks to...

 

So you are interested in using an Arduino Pro Mini or compatible board instead of one of the other larger boards to interact with your hardware devices. The Pro Mini does have some advantages over...

 

Not really a tutorial as I'm no good at writing tutorials, but important to know nevertheless.

WARNING: Relays can be used to switch very high voltages. Here in the UK 240VAC can easily...

 

Hi,

LCD Char Maker Tool.

Functionality

• Create custom LCD character with 5 pixel horizontal (cols), 8 pixel vertical (rows).
  Each row is represented by a byte with 5...

 

rRandomAccessFile v1.80 adds support for AsyncStreams in prefix mode.
All B4X development tools use AsyncStreams for network communication and now all of them support prefix mode...

 

Hello,
Not exactly a tutorial, but informative nevertheless.

This is how to map your Arduino projects to your WeMos. So for example in the blink demo, you just choose pin 2 for a WeMos instead of...

 

Understanding why you might need a pull up resistor...

Not exactly a tutorial from directly within this forum, but nevertheless I'm more than sure that this will help a few new B4R users...

 

Libraries are written in C++.
Libraries are made of a single h file and one or more cpp files. Libraries can also include other h files which will not be exposed.

All the files should be in the...

 

The EEPROM is in most cases the only persistent storage available. As a persistent storage we can use it to store data that will not be lost when the board is turned off.

The rEEPROM library...

 

Arduino C example #1:

void setup() {
  pinMode(13, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(13, HIGH);   // turn the LED on (HIGH is the...

 

Some of us may already know how to do that

http://www.rugged-circuits.com/10-ways-to-destroy-an-arduino/

 

This guide is obsolete ! It is no more updated.
Please use the B4X Booklets.

Here you find the B4R Beginner's Guide in pdf format.

The source code for the example programs is...

 

B4R & B4J experiment to monitor the state of a Reed switch connected to an ESP8266 - a NodeMCU is used. If the Reed switch state changes (triggered by a magnetic contact), data is send to a B4J...

 

A simple example that uses a Timer to change the state of pin 13 (this is the pin connected to the built-in led):

Sub Process_Globals
   Public Serial1 As Serial
   Private Timer1 As Timer...

 

Relays are electronic switches that allow low power (voltage) devices to control high power circuits.

In this example the ESP8266 board controls a regular 220v light bulb.

*** High power...

 

I using this code, Because Board has a problem for records size capacity of epprom.

Sample

Log("17:45:36 False >>",DateTime.TimeToUint(17,45,36,False)) '>>> 1065
    Log("1065 // 17:45:36...

 

I using this code, Because Board has a problem for records size capacity of epprom.

'For date >> 2015/ 08 / 04 (y/m/d)
Log("Date number:",DateTime.DateToUint(15,8,4)))
'returned >>
'Date...

 

The smaller Arduinos like the Arduino Uno have 2k of RAM. The subs stack and the global variables use this memory.

If your program includes constant data then you can use PROGMEM to store the...