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It works good but every time the nodemcu sends something, the TV signal gets distorted. That's correct. SoftwareSerial is terrible. Don't use it. When it's sending or receiving data nothing else at all can happen. If you have to resort to SoftwareSerial then you are using the wrong hardware for your project. Maybe an ESP32 would be a better choice. ...


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Software Serial is a pretty crummy library. It disables interrupts while receiving for long periods of time. That causes any other library that uses interrupts to have issues with timing. There are a plethora of other soft serial libraries out there. Try one of those instead. AltSoftSerial comes to mind.


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There is already an answer and comment about possible hardware / flow control issues, so this answer is only dealing with your Arduino sketch. Iv’e added a couple of print statements and the FreeMemory library to test your sketch. #include <MemoryFree.h> String data = ""; void setup() { Serial.begin(9600); while (!Serial); delay(1000); Serial....


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Check (e.g. with a multimeter) the DB9 voltages! Mostly RS-232 is used on those kind of connectors with voltages +-12Volts (there are other variants as well, up to 15V), but your Arduino's UART uses TTL levels (0V as logic low or 5V as high on a 5V Arduino). You'll need to convert these, possibly with a chip like MAX232 or similar. Also, for reverse ...


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Maybe its too late to respond but the line +FTPPUT: 1,65 indicates a server error. https://www.elecrow.com/wiki/images/2/20/SIM800_Series_AT_Command_Manual_V1.09.pdf - page 275. Please check a sequence of commands , maybe something is missing ? I use the following sequence : "AT+CREG?" "AT+SAPBR=3,1,\"Contype\",\"GPRS\"" "AT+SAPBR=3,1,\"APN\",\"NAME OF ...


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Last test showed it mangles data only when using println() and doesn't depend on the char type. Then I remembered something about CRLF in the Sigfox datasheet: Is recommended to use full duplex UART. In case of using half duplex, AT commands has to be ended only with one of ‘\r’ or ‘\n’ not both. Because if you send “AT\r\n” the Sigfox devkit starts ...


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I like the readBytes or readBytesUntil function. It doesn't end on a small gap between received bytes and fills the buffer. This functions are blocking with timeout, but if read some other device the input is usually fast and terminated reliably. example for readBytesUntil: if (Serial.available()) { char buff[32]; int l = Serial.readBytesUntil('\n', ...


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