changed the firmware on SIM900B

try to send get request http://dummy.restapiexample.com/api/v1/employee/1 AT+HTTPACTION=0returned +HTTPACTION:0,200,98

but, when I try to read (AT+HTTPREAD or AT+HTTPREAD=0,98)the response data I got broken response

expected result:


and actual results:





my Arduino code looks like that

void setup() {
  Serial.println("End of the setup");

void loop() {
  if (mySerial.available())
  if (Serial.available())
  • 1
    Edit the question : post your arduino code. Looks like a string overflow might be happening.
    – tavis
    Commented Nov 24, 2019 at 21:54
  • 1
    Maybe you're doing that silly "wait 5 seconds and assume there's a reply" thing I see all over the place. Or maybe you're using SoftwareSerial at 115200 baud... No one can know - unless you share your code...
    – Majenko
    Commented Nov 24, 2019 at 21:58
  • @Majenko, thanks, I've changed the baud to 9600 and it started work fine
    – JVic
    Commented Nov 24, 2019 at 22:22
  • @Majenko After doing mySerial.println("AT+HTTPACTION=0"); mySerial.println("AT+HTTPREAD"); delay(1000); //how do i get response without waiting a specific time.
    – b.john
    Commented Jun 16, 2022 at 6:23

1 Answer 1


Apparently you were running software serial at too high of a baud rate (57600) and bringing it down to 9600 fixed the issue.

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