[Solved] [ESP8266] How to format and process strings in LUA on ESP8266?

I am writing myself a program for the ESP-12 that is supposed to receive data from the UART, "slice" it and send it on over WiFi....

I'm stuck with formatting the data and can't move on ;(

To the point...
The data I send to the ESP looks more or less like this:

the a, b, c and ":" is constant, and "123", "456", "789" are my variables I want to work on. The variables are 1 to 7 digits long sometimes there is a "-" sign

How do I "slice" the string and substitute each variable further in the code?
I think it was best to cut everything between the constant "a:" and the space, but how do I do that?

If I do it this way I will send to ESP:

and in ESP:

then the variables must be of fixed length, but this is not the case

Thanks in advance for your help.

Variables are 1 to 7 digits long sometimes there is a "-" sign

This notation I do not understand.
Are there always or 3 characters after ":"? or is there a different number, from 1 to 7 characters?
i.e. a:1 b:1234567 c:456
is the array to be written string or dec?

Unfortunately, but there is a different number/length of characters (digits)
This is temperature, pressure, etc. There is a minimum of one digit and a maximum of seven

It doesn't matter how many there are, I'm just asking if there is a varying number, give all cases. Give some example frames

Yes, varying amounts. Examples of variables:
- temperature from "-30.0" to "40.0"
- pressure from "990.00" to "1100.00"
- humidity from "1" to "100"

i.e. ESP will receive e.g:
temp: -25 pressure: 997.99 humidity: 55

I think we have misunderstood each other, state exactly the frame you are sending to the ESP

piotr411 wrote:

I don't think we've misunderstood each other, specify exactly the frame you're sending to the ESP

piterek-23 wrote:

temp_external: -25 pressure: 997.99 humidity: 55

ok, in the morning I will write an example

Thanks
Or maybe it is possible to send the data to ESP in a different way so that it would be easier to "process" it in LUA?

I work with ESP with ATmega (BASCOM) and there I send the data like this:

Yes, it is easier as the frame will be in Bascom in this form:

print variable1,",",variable2,", ", variable3, "x"
i.e. you divide the variables by a comma, or another character, always the same.
I just don't know why you need an AVR for this? isn't it better to do everything in ESP?

And this is no longer a problem
So I should send like this:

so that ESP receives:

without spaces yes?

piotr411 wrote:

Only I don't know why to add AVR to it? wouldn't it be better to do everything in ESP?

There will be a total of 15 variables
AVR will do many other things

Rather, this is the notation I had in mind

(-25,55,997.99) or such (-25 55 997.99)

No unnecessary characters sent to ESP

Further I don't know why AVR, ESP is faster and has more memory, it can do much more, why complicate your electronics.

I need 6xADC i2c 8xGPIO
I like ESP, but in LUA I won't be able to do it all-C I don't know, and I understand BASCOM as-is and that's why this choice.

Please :



I haven't checked the program on ESP, I wrote on a tablet in LUA Comet.
I think Comet is very compatible with LUA ESP.

Off topic, if you know Basic, why are you writing in LUA?
ESP also has a very cool ESP Basic, this program is very easy to port to Basic.
Link

I assume you have read this: Link and then expand to adjacent links

piotr411 wrote:

The program on ESP I have not checked, I wrote on a tablet in LUA Comet.
I think Comet is very compatible with LUA ESP.

Thank you for the code. Now trying to somehow digest and understand it

piotr411 wrote:

Behind the topic, if you know Basic, why are you writing in LUA?
ESP also has a very cool ESP Basic, this program is very easy to port to Basic.
[url=]http://www.esp8266basic.com[/url]

I so honestly didn't know there was an ESP Basic
I have seen most things written in LUA or C. There are also projects that use AT commands (but that didn't work for me)
I stayed with LUA because somehow I started to understand it.

JacekCz wrote:

I assume you have read this: Link and then expand to neighbouring links

I had not seen this. Thank you for the link.

turlam.dropsa wrote:

People have invented something like I2C so connecting ADC and IO expanders is no problem for ESP.

You're 100% right, but it's quicker to do something on AVR + BASCOM than to write code for ESP + all the devices connected to it.

I know I'm asking about simple things. Many Things can be done better, differently.
I am a Sunday electronics amateur and I do as I can, and I can't do too much
For the moment I'll stay with what I have, and as I grow I'll move onto ESP and more ambitious projects. You have to start somewhere.

In this example Link

Array entry starts with ":" and ends with " "(space)
It doesn't matter how many variables or how long, it was meant to be universal

Now a simple example, also universal, it doesn't matter how many variables and how long they are, but you have to send the ESP the variables themselves, separated by a space, according to the formula"

Bascom:


Lua:



niveasoft - you have assumed too many constants in the example

JacekCz wrote:

I assume you have read this: Link and then expand to adjacent links

It is not easy to switch from Basic to LUA on the fly, there are too many characters in LUA for instructions that are not present in Basic. It is easier from C to LUA, because it is almost C but on a higher level. Therefore, beware of applications where high performance is needed and LUA does not provide for assembler insertions To top it off, LUA ESP is extremely poorly optimised, which may not be feasible for certain projects. The added modules in LUA serve as in ARDUINO for fun, i.e. nothing serious. If one is to seriously exploit the potential of ESP then only Eclipse Mars with SDK and the C language remains

There are many ways to perform character operations in LUA. The next example will be, writing sequentially to an array of just numbers allocated with any characters, letters etc...in any number of characters. Here LUA has very wide possibilities, there is a multitude of operators available. After thinking about it for a while longer, I found 9 ways to solve the problem;) I will add more in my spare time. They will no longer be simple to interpret on Basic

piotr411 wrote:

Now a simple example, also universal, does not matter the number of variables and their length, but to the ESP you must send the variables themselves, separated by a space, according to the formula."

Bascom:

Code: vbnet [expand] [select all]
a$="-25 99.999 55" '- here we have 3 variables, you can give them 7 or 100 it doesn't matter, each one will be sequentially written into the array
Print a$


Lua:

Code: lua [expand] [select all]
str = "-25 55 99.999" -- LUA
tab ={} a=0

for i in string.gmatch(str, "%S+") do
a=a+1
tab[a]=i
end

-- here you read what you have written to the array
print ("Number of variables found in string str:",a)
print ("tab[1]) -- a 1 in the array means reading the data from position 1 -there you have written -25

I'm trying to do this method and flop....
If I send seven variables from the AVR it is OK, but if there are more then nothing ;(
The ESP in the console is chugging along:

well, unfortunately regular expressions cost money (gmatch, gsub),
I sometimes argue with programmers who love to use them - the argument is not always about performance (on hyper machines), but e.g. wrong when you should use a mini-parser (the parser "understands" what it strips, w.r. just cuts and finds) . This is so outside the thread


try the part of the article where it says "PHP-like explode". Lua itself has a pretty good set of string processing functions (it doesn't have the popular "split") and this article presents various approaches

In most languages the "split" function/method does not use the regular expression engine, but I guess some do.

EDIT I am aware that my advice has a bit of the rabbi who Ick cured a sick goat at a distance....

Have you tested the first example?
It is less appetising to remember.

A bit strange, with me after typing 20 variables it works and there is still, a free 17KB of memory.

What Firmware do you have?

JacekCz wrote:

EDIT I am aware that my advice has a little of the rabbi who Ick cured a sick goat at a distance.... [/i]

And yes and no... For the moment I didn't understand much of what you said, but I often have that I'll ask for help and someone will hint at something and I don't really understand it, but after a while I go back to the statement in question and the glare of "I know what that person was trying to convey"

piotr411 wrote:

First example have you tested?
It's less appetizing by memory.

Not yet because I don't quite know how to use it

piotr411 wrote:

Some strange, at my place after entering 20 variables it works and there is still, free 17KB of memory.

Then maybe (surely) I'm doing something wrong?

Maybe I'll show the whole thing, it'll be easier....
init.lua

avr.lua

piotr411 wrote:

What Firmware do you have?

There is something to optimise, a lot of memory is taken up by your text, think of one variable substituted and in part only modified.

@piotr411 Can you tell me how to use your code (post #14) i.e. what data to send from the AVR and how to substitute my uC01-uC20?

Exactly the same as with example no. 2
a=(data) - - what comes from uart

Note the formatting of the variable data
Recognition starts with : and ends with a space
The rest is unchanged everything goes into the array.

Get rid of the text from the file because it takes up too much memory. Write what is repeated to the function and refer to it. This will save a lot of RAM space. Flash has a lot of 4MB and you don't need to save here, but take care of the RAM because there will be messages like the one above. LUA leaves 20kb and so you have to combine to fit.

instead of:
SensorIp01 = "192.168.222.1"


replace:
SensorIp00 = "192.168.222."
a, the following:
SensorIp01 = "1"
etc.......
at the end you will combine both variables.
Wherever you have repetitive text data do the same.

This eats up all the memory :
.. " HTTP/1.1Host: NettempIPHost"
.. "Authorization: basic YWRtaW46MTk4MQ=="
... "Connection: ke ep-aliveAccept: */*")
divide this into 3 variables and link when you send i.e. the easiest way is to refer to a function e.g:



Originally it took 14kb, after this change it's already 3kb, and you can still rip off 1kb.

Oh dear... Thanks a lot for such explanations and codes
I'm already getting to work.

Perhaps more




Beyond that, I don't think the programme is fully thought through.
For what purpose do you check all the sensors at once?
Some environmental conditions occur more slowly and there is no need to, ask yourself so often.

The programme can still be heavily shortened and given more intelligence.
Watching now what you want to build.
I still say the AVR is unnecessary and only complicates the project.

Added after 22 [minutes]:

So now we are at 2kb

piotr411 wrote:

Beyond that, I don't think the programme is entirely well thought out.
For what purpose are you checking all the sensors at once?
Some environmental conditions occur more slowly and there is no need to, ask yourself so often.

You are right, but I have left such optimisation of the reading frequency for later.

piotr411 wrote:

The program can still be heavily shortened and given more intelligence.
Watching now what you want to build.
I still maintain that the AVR is unnecessary and only complicates the project.

If I were to start writing this in LUA this ESP would have to have with 1GB of memory

I don't know myself what I am doing wrong anymore because by doing according to your instructions I get:


The code looks like this:


Changed:

to:

because I was getting the message:

supposedly I can send whatever I want, it does not necessarily have to be an IP

Added after 1 [hour] 21 [minutes]:

hmmm... tries your first code and uC sends:

ESP doesn't shout anything that there is something wrong, but it doesn't send the data any further either

Added after 5 [hours] 16 [minutes]:

I think I need to look for an ESP with more memory....

What I did this time was to get rid of avr.lua and move everything to init.lua because I thought maybe something would be freed up here or something, but of course nothing.
At most it sends me 9 data and no more is possible

init.lua