How to cause a SQL Server database integrity error, OSPF Advertise only loopback not transit VLAN. Is this another learning exercise or are you actually trying to initialize the variable, e.g. You will get a compiler error if you try to assign a value to a const variable. If engine worked 255hrs.30 mtsit will store the each hours (2,5,5) in different Eeprom address and minutes in a single address (30).. i have two option: firebase arduino master and Firebase Arduino Client Library for ESP8266 By Mobitz. Was the phrase "The world is yours" used as an actual Pan American advertisement? How can one know the correct direction on a cloudy day? here is my code: there is no reason for command to be a String array. What are the benefits of not using private military companies (PMCs) as China did? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. That is 100 times more complicated than it needs to be. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. @econjack: the example you posted won't compile or work. Your Answer Thanks for contributing an answer to Arduino Stack Exchange! It only takes a minute to sign up. to 255, Store minutes as a uint32_t. Post your code, post your error messages. Output a Python dictionary as a table with a custom format. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Floating-point numbers are often used to approximate analog and continuous values because they have greater resolution than integers. Was the phrase "The world is yours" used as an actual Pan American advertisement? I think C uses type int for intermediate values in which case the worst expected case (255*100) should not exceed the limits of a type int variable. Other than heat. Also see the reference of String Object Constructors to construct String objects correctly. What was the symbol used for 'one thousand' in Ancient Rome? Using this conversion website, I've tried converting like so: While this compiles, it always returns 0 (not 127 like I expect). I used the code: float latitude = atof (pdop.value ()); float deg = (int) latitude; serial.print (deg); Was the phrase "The world is yours" used as an actual Pan American advertisement? Sintaxis: variable_string.toFloat (); Puedes dejar un y suscribirte Activa la. Thanks for contributing an answer to Stack Overflow! I have a value for led brightness that is stored as an unsigned char (0-255). The best answers are voted up and rise to the top, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. How does the OS/360 link editor create a tree-structured overlay? Follow answered Mar 16, . This means that the variable can be used just as any other variable of its type, but its value cannot be changed. Not the answer you're looking for? You will certainly never get a const anything from a GPS. Why not simply save the actual float in EEPROM rather than messing around with strings and atof() when you want to read it back ? 585), Starting the Prompt Design Site: A New Home in our Stack Exchange Neighborhood, which is the number of bits in a float variable. Connect and share knowledge within a single location that is structured and easy to search. Because of this, the incoming coordinates are stored as Strings. By clicking Post Your Answer, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct. Connect and share knowledge within a single location that is structured and easy to search. But it fails when trying to prepare for sending to the mqtt server. of being printed, the content is stored as a C string in the buffer Ok, you're the smartest one in the room and you come here to feel superior to others and not provide any real help. GDPR: Can a city request deletion of all personal data that uses a certain domain for logins? If you want a float, you can use atof in conjunction with the toCharArray method: char floatbuf [32]; // make this at least big enough for the whole string curLongitude.toCharArray (floatbuf, sizeof (floatbuf)); float f = atof . to 255. J-M-L: Please be sure to answer the question. How should I ask my new chair not to hire someone? Google is the quickest and most reliable way to help you learn how to use standard functions. Thanks for contributing an answer to Stack Overflow! How could submarines be put underneath very thick glaciers with (relatively) low technology? Convert Float to String Using the concat () Function in Arduino To convert a float into a string using concat () first, define an empty string and then pass the float number as a parameter in the concat () function. The supplied link was clickable. It gives error Invalid operands of types 'unsigned char*' and 'float' to binary 'operator*'. Why would a god stop using an avatar's body? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. constant, not in the struct). How to cause a SQL Server database integrity error. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing, I regret to inform you that it's not just Arduino that can't do it, but every C++ compiler in existence because this is not valid C++. //--> Defines the type of DHT sensor used (DHT11, DHT21, and DHT22), in this project the sensor used is DHT11. Suggest corrections and new documentation via GitHub. Object constrained along curve rotates unexpectedly when scrubbing timeline, Novel about a man who moves between timelines. c++ - Arduino cannot convert 'float' to 'const char*' in initialization - Stack Overflow Arduino cannot convert 'float' to 'const char*' in initialization Asked 5 years, 8 months ago Modified 5 years, 8 months ago Viewed 3k times -3 float diff = 0; const char* str [] = {"Err: ZPROBE: ",diff}; LCD_ALERTMESSAGEPGM (str); 1 Answer Sorted by: 2 String.c_str () return a const char* array, which is not compatible with your static char* msg. aarg: How could I cast c++ const float* to char * type? "35" was just an arbitrary value I sent to see if it would show up in openHab and it does! Why does the present continuous form of "mimic" become "mimicking"? After googling to try and find what that means I'm just not getting how to fix it temp = (dht.readTemperature() * 9.0)/5.0 + 32.0; How can I calculate the volume of spatial geometry? Making statements based on opinion; back them up with references or personal experience. temp = (dht.readTemperature() * 9.0)/5.0 + 32.0; snprintf (msg, 75, "35", value); It is your choice, and it cost nothing to try. snprintf (msg, 75, temp, value); I participate in several forums and answer basic questions all the time for those starting out rather than berate them. Provide details and share your research! rev2023.6.29.43520. Why is there inconsistency about integral numbers of protons in NMR in the Clayden: Organic Chemistry 2nd ed.? Did you read the web page? please help. I have an led brightness that is stored as an unsigned char (0-255), This is not an array of unsigned char, this is an array of Sorry should add that in the environment i'm using - 'string' : is not a member of 'std'. for my applications, so I find this method helps me with the addressing. Not sure what you are trying to do. For quick help and reliable links that inform how to use standard functions, use google. If you instead write. As stated above this programming language is very new to me, I'm just starting out with this over my head complicated project. However, I keep on getting this error "cannot convert 'String' to 'const char*'". I do the same and add on top a magic number (like 0xDEADBEEF or 0xBADCAFFE) in EEPROM. Is there any particular reason to only include 3 out of the 6 trigonometry functions? Find centralized, trusted content and collaborate around the technologies you use most. Thanks for the quick reply, but unfortunately you're talking over my head and I don't understand. Consider also that snprintf() is possibly the most complex, versatile function in the C/C++ language. Making statements based on opinion; back them up with references or personal experience. From an example I downloaded and edited for my wifi and mqtt server I was able to make the following work. Damian01: That is 100 times more complicated than it needs to be. Processing Electronics (Arduino, etc.) for my applications, so I find this method helps me with the addressing. please give me the directions for applying atof() to ma program, sreekanthmp: // Check if any reads failed and exit early (to try again). I think its because i did not change char[] in to float.Can anyone tell me how to correct my mistake. How common are historical instances of mercenary armies reversing and attacking their employing country? Making statements based on opinion; back them up with references or personal experience. In any other C/C++ platform, you can use "%f" as a format specifier when you want to print (or convert to string) a float using printf or its siblings. rev2023.6.29.43520. Aka, a pre-made program for my needs. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. If you didn't want to help, you could have passed by and not said anything jremington: Can the supreme court decision to abolish affirmative action be reversed at any time? Connect and share knowledge within a single location that is structured and easy to search. Thanks for contributing an answer to Arduino Stack Exchange! Because hours and minutes have a fixed relationship, the only value in splitting them, is for some calculations and human display and reckoning. How to describe a scene that a small creature chop a large creature's head off? I have found that when working with eeprom, it is easiest, at least for me, to create a struct of all the things I want to put in eeprom, and a function to write this struct to eeprom and a function to read this struct from eeprom. How do I fill in these missing keys with empty strings to get a complete Dataset? Actually this program count the engine working hours once engine started and and its stores the the value at the time engine off. To learn more, see our tips on writing great answers. curLongitude.toInt () ). Share. Which fighter jet is seen here at Centennial Airport Colorado? How can I multiply 255 by 0.5 to get ~127 ? Aka, if you don't know what something does don't just use it. Is it possible to "get" quaternions without specifically postulating them? 585), Starting the Prompt Design Site: A New Home in our Stack Exchange Neighborhood, Cannot convert 'String' to 'uint8_t {aka unsigned char}' in initialization, Help decrypting AES string from arduino rf module in python. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Just store the number of minutes in a single unsigned long integer variable. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. should i use the : firebase arduino master?? Improve this answer. Do native English speakers regard bawl as an easy word? rev2023.6.29.43520. It helped me achieve it. of digits after the decimal sign. jremington: How to describe a scene that a small creature chop a large creature's head off? Find centralized, trusted content and collaborate around the technologies you use most. cannot convert 'const char*' to 'float' Using Arduino Programming Questions Damian01 February 19, 2020, 7:30pm 1 I would like to convert GPS data which are const char example: 5020.37660 to float number but I have a problem.