ESP8266 Arduino: Adding Newline to String Responses for Smartphone App

Hello, I am testing a WiFi TCP/UDP controller program on a smartphone, I send a command from the smartphone and the ESP8266 responds. That it responds correctly I know because when I send commands from the PC the responses come without a problem, but in the smartphone in the program I do not see the response. For example, the ESP8266 responds with a string like this: "W1_OFF". I suspect that you need to add an end of line character or Enter or maybe both to the end of the text sent from the ESP. Program in ESP8266 written in arduino. How do you add a newline or an enters character at the end of text sent from the arduino?

Added after 20 [minutes]: .


Sending text:


Using the command:

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If you want to have special characters in the text you write them with "ƒ", e.g. "W1_ON", where r is return and n is new line.

Thank you for your response.

The WiFi TCP/UDP Controller is not receiving data from the ESP, I've been trying various ways and nothing and with characters at the end and without unfortunately without success.

I have a question, what if I wanted to send a string built as follows:

int voltage = 5;
int natexenir =1;

and the string would look like :
voltage, value of voltage, natexenir, value of natexenir

What I mean is how to build strings from pre-made strings plus single characters plus numeric values.

heyka wrote:

What I mean is how to build strings from ready-made strings plus single characters plus numeric values.

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Here is the basic information: https://www.arduino.cc/reference/en/language/variables/data-types/stringobject/

Added after 9 [minutes]:

Or alternatively operate on C-style text strings using the sprintf() function:
http://www.cplusplus.com/reference/cstdio/sprintf/

Strings in Arduino can be added and converted, e.g. String0=String1+String2+String(number)+String3; and then Serial.println(String0);. It is safer, however, to use a static char array as a buffer for everything and in it locate individual characters one by one, e.g. with the sprintf function Link . In either case you have to bear in mind that RAM is not made of rubber, and in AVR it is severely limited. Nevertheless, with Strings surprises happen more often, with a static array you will immediately see that you have overstepped and cut something off.

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The command above sends data as a string through the port.

How do I send it over UDP?

command



sends an array of char, and I mean to send a string c .

There are functions in Arduino to convert between a char and String array. You've already had links given to the Arduino Reference, and there's a list of functions/methods with examples at the bottom.

Such an example:

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is this what the text in the buf variable will look like?

voltage,5,intensity,1

heyka wrote:

is this what the text in the buf variable will look like?

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No, it should be:
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if the text should look like this:

heyka wrote:

tension,5,intensity,1

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and the buffer buf[] must be larger to accommodate all characters of the text.

Great, thanks it's OK.

I have the NodeMCU module and library for the BPM 280 running over SPI

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What needs to be changed to fire it on I2C?

I just connected it to I2C, I didn't even check the operation over SPI. Try changing what you commented in the sketch to I2C (actually the example is under I2C) and connect it under the I2C pins of the Arduino. If something didn't click check if the I2C scanner detects it on the bus.

kaczakat wrote:

I just connected it to I2C, I didn't even check the operation over SPI. Try changing what you commented in the sketch to I2C (actually the example is under I2C) and connect it under the I2C pins of the Arduino. If something didn't work check if the I2C scanner detects it on the bus.

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I don't have an Arduino board, just a NodeMcu, and this board doesn't have hardware I2C, is it possible to run the I2C scanner?

heyka wrote:

is it possible to run an I2C scanner?

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Can do: https://roboindia.com/tutorials/i2c-address-scanner-nodemcu

The scanner will work, although on the page there is a reverse description of D1-SCL and D2 -SDA, it read me the address 0x76

Added after 5 [minutes]:

It works, BMP280.h was address Ox77, I changed it to 0x76 and it works.

Added after 1 [minute]:

Now it's time for the BME280 and I2C.

Maybe it will be useful to someone, I know no discovery but ready to upload and test.

Working test programs, NodeMCU v3 board, modules work over I2C
In the BMP280.h file you need to set the module address, in my case

#define BMP280_ADDRESS (0x76)

BMP280

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BME280



OLED display, address 0x3C and #define OLED_RESET -1

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Added after 1 [hour] 54 [minutes]:

I am displaying temperature, humidity and pressure on an OLED display, the quantities are displayed to me with two decimal characters, how do I truncate one or two characters occurring after the decimal point?

For example, I display humidity using the function:

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heyka wrote:

how do I truncate one or two characters occurring after a comma?

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Source

Thanks, of course it works as I wanted it to.

The link my colleague gave me is for Serial.print, but the formatting method works for both lcd.print and dispaly.print, hence my question:
- is this some kind of standardisation of sending sending strings whether via serial port or on oled etc?
-function bme.readPressure() for bme280 returns pressure as a string what is this string, c-string?

heyka wrote:

The link my colleague gave me is for Serial.print, but the formatting method works both for lcd.print and for dispaly.print, hence my question:

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Both classes inherit the print() and println() methods from the base class Print , so the method calls are identical.

And one more question, does the NodeMCU support any external interrupts such as INT for uP e.g. AVR.

heyka wrote:

And one more question, does the NodeMCU support any external interrupts

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As much as possible. Here it is explained: https://www.electronicwings.com/nodemcu/nodemcu-gpio-interrupts-with-arduino-ide

Classes inherit. So it's object-oriented programming? This is already too high a level for me .

heyka wrote:

Classes inherit. So it's object-oriented programming?

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If you program with Arduino HAL and C++ then there is no turning back .

I am starting out with an Arduino.

It used to be Bascom, C and now Arduino.

I'm now taking the RTC DS1307, https://abc-rc.pl/product-pol-6190-Modul-czas...s&utm_medium=google_shopping&curr=PLN (can't insert link in tags), using test programs from http://www.jarzebski.pl/arduino/komponenty/zegar-czasu-rzeczywistego-rtc-ds1307.html

Header file for the library

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I have a question, the first initialisation function of the module looks as follows

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while its call in the sketch looks like:

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Where did the 'clock' come from?

I have this sketch



function


sets the time from the computer at compile time,

How do you set any other arbitrary time?

I tried like this



but it doesn't compile

Please help.

Added after 49 [minutes]:

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compiles but does not set this time.

Read up on C++, because asking every letter on the forum will take you a long time to create anything.
In the same way as you create a variable "int variable;" and then use it in code "variable++;" the same way you create objects "DS1307 clock;" and then use functions/methods on them.
For a start I recommend M. Zelent's course on C++ and object-oriented C++, it's on Yutube, and some book will complement this introduction.
And with setting the time you are supposed to give two arguments to the function (separated by commas), and you are trying to give six - seriously though this video course.

It's supposed to rain all day so, I'll take a C++ course.

I would like to go back to the time setting for a moment, I have 3 functions in the header file (strange because they all have identical names):

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Isn't the first one for setting the time in a format like I wanted to do, i.e. giving 6 arguments.

As for the third one, should you create arrays of type Char and insert them when calling the function?

Setting the time using one of the functions from this library https://github.com/jarzebski/Arduino-DS1307 might look like this :
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First - during compilation
Second - using the timestamp, i.e. the number of seconds from 01.01.1970 to now
Third - by giving 6 arguments in the right order, i.e. year, month, day, hour, minute, second

Greetings

Slawek K. wrote:

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Third - by providing 6 arguments in the correct order i.e. year, month, day, hour, minute, second

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The test code from the author's page, should change the time in the layout, but it does not, it still remains the current one that was set at compilation.

Throw out the if condition and leave the setDateTime function alone.

Slawek K. wrote:

Drop the if condition and leave the setDateTime function alone.

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Thanks.