问题
I am using a SIM900 module with my Arduino and it is missing characters although it is returning the right number of characters expected. I have ERROR on AT+SAPBR=1,1 and AT+HTTPINIT so I am not sure if this is the reason for it. Im not sure how to fix these issues either.
AT+CGATT?
+CGATT: 1
OK
AT+CGATT=1
OK
AT+SAPBR=3,1,"CONTYPE","GPRS"
OK
AT+SAPBR=3,1,"APN","mobile.o2.co.uk"
OK
AT+SAPBR=1,1
ERROR
AT+HTTPINIT
ERROR
AT+HTTPPARA="URL","http://www.xxxxxxxxxxx.com/temp/"
OK
AT+HTTPACTION=0
OK
+HTTPACTION:1,200,56
AT+HTTPREAD
+HTTPREAD:56
{"type":"dOK
My function that reads characters as they come in:
void whileAvailable() {
char data;
while (SIM900.available()) {
data=SIM900.read();
if (data>0) Serial.print(data);
}
}
I believe the function is reading characters fine however I am not sure why it is failing the find the rest of the characters
回答1:
This is due to Serial buffer overflow of arduino uno or mega you use. Increase the buffer size so that they will accommodate more bytes; and those data can be displayed.
来源:https://stackoverflow.com/questions/33838165/httpread-missing-characters-with-arduino-and-sim900