I have a trouble when i'm using SIM800L module with common ground with combinaison with : FTDI232+ARDUINO PRO and Li-po battery. I use common ground to allow Arduino see the serial of SIM800L.
I use battery (lipo) to power the SIM800L to allow 2A peak current.
Serial work but sometime the module reset(i think) and i see strange character. The SIM800L no work correctly.
I meet the same trouble when i use the FTDI's VCC, every time I use the common ground i have this problem.
Look the gif you can see the problem :
It's strange because when i connect the SIM800L directly with FTDI232 i have no problem all work fine.
I use this code to debug the Serial communication :
#include <SoftwareSerial.h>
SoftwareSerial serialSIM800(RX,TX)
[..]
//On Setup
Serial.begin(115200);
while(!Serial);
//Being serial communication witj Arduino and SIM800
serialSIM800.begin(115200);
delay(1000);
serialSIM800.print("AT\r");
//[..]
void loop(){
if (serialSIM800.available())
Serial.write(serialSIM800.read());
if (Serial.available()) {
while(Serial.available()){
Serial.print(">");
char test=Serial.read();
Serial.print(test);
Serial.println();
serialSIM800.write(test);
}
There are a few things that escape me that's why I need your lights, thanks by advance. Regards
Software Serial
which is always a candidate for suspicion. I understand that you debug from the pc via FTDI. You maybe better debug using Arduino Mega since it has multiple hardware serials until you satisfied with your project and port the code to the Arduino Pro afterward. And second thing is If Arduino Pro version is 3v (you didn't mention) and causing logic levels issues. – Sener Apr 18 '17 at 8:40