# Need help c++ programming esp8266 **URL:** \ **Category:** Home Automation\ **Tags:** esp8266, programming\ **Created:** [August 21, 2018, 10:51am UTC](https://community.openhab.org/t/need-help-c-programming-esp8266/49800 "2018-08-21T10:51:47Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![aymeric106](https://community.openhab.org/letter_avatar_proxy/v4/letter/a/db5fbb/32.png) [@aymeric106](https://community.openhab.org/u/aymeric106)\ **Post date:** [August 21, 2018, 10:51am UTC](https://community.openhab.org/t/need-help-c-programming-esp8266/49800/1 "2018-08-21T10:51:47Z")
Hello, Not really an openhab question, but maybe someone can help me: I’m reworking an example of [GitHub - crankyoldgit/IRremoteESP8266: Infrared remote library for ESP8266/ESP32: send and receive infrared signals with multiple protocols. Based on: https://github.com/shirriff/Arduino-IRremote/](https://github.com/markszabo/IRremoteESP8266) to fit my need. I’m using the example as a base [IRremoteESP8266/examples/IRMQTTServer at master · crankyoldgit/IRremoteESP8266 · GitHub](https://github.com/markszabo/IRremoteESP8266/tree/master/examples/IRMQTTServer) The ESP8266 is waiting for MQTT request and send an InfraRed signal depending on the mqtt data received What I like to do is send a infrared command as a string parameter in my MQTT request, and the ESP8266 needs to find that string in a small ‘database’ and send the correct IR. `mosquitto_pub -t "ESP8266/send_ir" -m "SAMSUNG_POWER_ON"` The context: the function receivingMQTT below is triggered every time a MQTT request is received. Here’s what I have **samsung\_code.h** // Samsung IR Code, Globalcache Format ```auto #define SAMSUNG_POWER_OFF "38000,1,1,173,173,21,65,21,65,21,65,21,21,21,21,21,21,21,21,21,21,21,65,21,65,21,65,21,21,21,21,21,21,21,21,21,21,21,21,21,21,21,21,21,65,21,65,21,21,21,21,21,65,21,65,21,65,21,65,21,21,21,21,21,65,21,65,21,21,21,1832" #define SAMSUNG_POWER_ON "38000,1,1,172,172,22,64,22,64,22,64,22,21,22,21,22,21,22,21,22,21,22,64,22,64,22,64,22,21,22,21,22,21,22,21,22,21,22,64,22,21,22,21,22,64,22,64,22,21,22,21,22,64,22,21,22,64,22,64,22,21,22,21,22,64,22,64,22,21,22,1820" ... ``` **esp8266.ino** ```auto void receivingMQTT(String const topic_name, String const callback_str) { ... ... int ir_type = GLOBALCACHE; // >we are sending a GLOBALCACHE formatted string char *code; debug("Receiving data by MQTT topic " + topic_name); debug("MQTT Payload (raw): " + callback_str); // ->>> Here we need to affect the correct value to code // If (callback_str =="SAMSUNG_POWER_ON") code="38000,1,1,173,173,21,.." // // send received MQTT value by IR signal sendIRCode(ir_type, code,"",0, 0); } ``` here’s the definition of sendIRCode, only 1st and 2nd parameters are really used in our case ```auto // Transmit the given IR message. // // Args: // ir_type: enum of the protocol to be sent. // code: Numeric payload of the IR message. Most protocols use this. // code_str: The unparsed code to be sent. Used by complex protocol encodings. // bits: Nr. of bits in the protocol. 0 means use the protocol's default. // repeat: Nr. of times the message is to be repeated. (Not all protcols.) void sendIRCode(int const ir_type, uint64_t const code, char const *code_str, uint16_t bits, uint16_t repeat) ``` **So: how from the string “SAMSUNG\_POWER\_ON” find the string '“38000,1,1,173,173,21…”, and assign it to the the var ‘code’** Thank you 😀 ---
**Author:** ![vzorglub](https://community.openhab.org/user_avatar/community.openhab.org/vzorglub/32/17166_2.png) [@vzorglub](https://community.openhab.org/u/vzorglub)\ **Post date:** [August 21, 2018, 10:58am UTC](https://community.openhab.org/t/need-help-c-programming-esp8266/49800/2 "2018-08-21T10:58:17Z")
```c++ If (callback_str =="SAMSUNG_POWER_ON") code=SAMSUNG_POWER_ON ``` ---
**Author:** ![aymeric106](https://community.openhab.org/letter_avatar_proxy/v4/letter/a/db5fbb/32.png) [@aymeric106](https://community.openhab.org/u/aymeric106)\ **Post date:** [August 21, 2018, 11:07am UTC](https://community.openhab.org/t/need-help-c-programming-esp8266/49800/3 "2018-08-21T11:07:11Z")
Yes, but there’s 150 lines in samsung\_code.h … … I can do that but … ```auto If (callback_str =="SAMSUNG_POWER_ON") code=SAMSUNG_POWER_ON If (callback_str =="SAMSUNG_POWER_OFF") code=SAMSUNG_POWER_OFF If (callback_str =="SAMSUNG_VOLUME_UP") code=SAMSUNG_VOLUME_UP ... ``` ---
**Author:** ![vzorglub](https://community.openhab.org/user_avatar/community.openhab.org/vzorglub/32/17166_2.png) [@vzorglub](https://community.openhab.org/u/vzorglub)\ **Post date:** [August 21, 2018, 11:19am UTC](https://community.openhab.org/t/need-help-c-programming-esp8266/49800/4 "2018-08-21T11:19:51Z")
Instead of using define for each code, use one define for a json string will all your codes with the name as key. Then use the json library to retrieve your code with the key sent in mqtt ---
**Author:** ![aymeric106](https://community.openhab.org/letter_avatar_proxy/v4/letter/a/db5fbb/32.png) [@aymeric106](https://community.openhab.org/u/aymeric106)\ **Post date:** [August 21, 2018, 9:22pm UTC](https://community.openhab.org/t/need-help-c-programming-esp8266/49800/5 "2018-08-21T21:22:51Z")
Thank you, I didn’t use JSON actually, because i was getting low on memory with all those codes. So I choose only the code I really need. Anyway I saw an nice tutorial about ESP8266 programming thanks to you. (it’s in french, but something tell me you understand french, don’t you ? 🤨 ) [https://projetsdiy.fr/esp8266-webserveur-partie4-arduinojson-charger-enregistrer-fichiers-spiffs/](https://projetsdiy.fr/esp8266-webserveur-partie4-arduinojson-charger-enregistrer-fichiers-spiffs/) Aymeric ---
**Author:** ![vzorglub](https://community.openhab.org/user_avatar/community.openhab.org/vzorglub/32/17166_2.png) [@vzorglub](https://community.openhab.org/u/vzorglub)\ **Post date:** [August 21, 2018, 10:27pm UTC](https://community.openhab.org/t/need-help-c-programming-esp8266/49800/6 "2018-08-21T22:27:55Z")
Yes but that uses JSON It’s unlikely that you were running low on memory on an ESP module What size is your programme? ---
**Author:** ![aymeric106](https://community.openhab.org/letter_avatar_proxy/v4/letter/a/db5fbb/32.png) [@aymeric106](https://community.openhab.org/u/aymeric106)\ **Post date:** [August 22, 2018, 7:47am UTC](https://community.openhab.org/t/need-help-c-programming-esp8266/49800/7 "2018-08-22T07:47:31Z")
It’s basically a tweaked example here > Added the Daikin library to control my AC, and the Samsung IR codes for my TV. first i added the 175 lines of data like you suggest ```auto If (callback_str =="SAMSUNG_POWER_ON") code=SAMSUNG_POWER_ON If (callback_str =="SAMSUNG_POWER_OFF") code=SAMSUNG_POWER_OFF ... ... If (callback_str =="SAMSUNG_VOLUME_UP") code=SAMSUNG_VOLUME_UP ``` It won’t even compile in Arduino IDE Next I made a selection, keeping perhaps 40 codes. I have a warning about free memory availaible for local variable. But that’s OK, I’ll clean the code to remove all I don’t use and l’ll be fine. I spent way to much time on this 🤣 ! And all this var casting in c++ is killing me “string, char \* , atoi, .c\_str(), strdup,unint16 32 int,” can’t we have numeric and string … (and now I have another idea to feed my fish with an arduino or esp and a small motor …) ---
**Author:** ![vzorglub](https://community.openhab.org/user_avatar/community.openhab.org/vzorglub/32/17166_2.png) [@vzorglub](https://community.openhab.org/u/vzorglub)\ **Post date:** [August 22, 2018, 7:51am UTC](https://community.openhab.org/t/need-help-c-programming-esp8266/49800/8 "2018-08-22T07:51:49Z")
> [@aymeric106](#): > > I have another idea to feed my fish Poor fish!! 😆