Side note, I'm a complete noob with electronics (i'm a software engineer) so this is all new to me!
I have an arduino uno, and a SIM800L, and I was following a guide to wire it all up properly (I understand the 800l can't take 5V straight so I read about putting some resistors in).
I used the guide on this site about the 10K and 20K resistors.
Problem is, the output i see in the serial monitor is a bit weird?
This is the output
I just bought a cheap GiffGaff sim card and activated it and plonked it in...
I don't think the values are meant to be what they are though... am I doing something wrong?
Below is an image of my setup:
I haven't put anything on the SIM card in terms of credit so... don't know if that's something I need to do first?
Also, please don't post pictures of text - just copy and paste the text.
A photo of the hardware is not useful for showing connections - it is too easy to misinterpret. A photo of a simple pencil drawing showing all your connections would be much better.
And please post your program.
It would also be a big help if you provide an example of the correct output that should have been received for comparison with what was actually received.
I took a picture of how everything is laid out on my breadboard. I equally explained that my setup is EXACTLY the same as how it is in the above diagram. Everything is connected correctly and all the voltages are correct (confirmed using a multimeter). My question was about the output of the SIM800L using the AT commands and how the output was different, i.e. CSQ was showing 0, 0, and CREG was showing 0,2. I had read that this means your signal quality is 0 and a number of 2 for CREG means the SIM is not registered, though I could be wrong. I was wondering if this was a problem with how the Arduino is linking up in general to the SIM800L.
In the image, the resistor going horizontally is a 10K resistor, and the 2 going vertically are both 10K (totalling to 20K). All pins are connected to the pins given in the example above i.e. what I circled in the above diagram. That's how it is laid out on my breadboard.
The onboard LED indicator will blink once every two to three seconds when it has completely registered the SIM to a network. When the LED indicator is blinking every second, this means that the SIM800L is still searching for a network to register onto.
It's still blinking every second. I've tried putting another SIM but still getting the same issue. My commands are as follows:
#include <SoftwareSerial.h>
//Create software serial object to communicate with SIM800L
SoftwareSerial mySerial(3, 2); //SIM800L Tx & Rx is connected to Arduino #3 & #2
void setup()
{
//Begin serial communication with Arduino and Arduino IDE (Serial Monitor)
Serial.begin(9600);
//Begin serial communication with Arduino and SIM800L
mySerial.begin(9600);
Serial.println("Initializing...");
delay(1000);
mySerial.println("AT"); //Once the handshake test is successful, it will back to OK
updateSerial();
mySerial.println("AT+CSQ"); //Signal quality test, value range is 0-31 , 31 is the best
updateSerial();
mySerial.println("AT+CCID"); //Read SIM information to confirm whether the SIM is plugged
updateSerial();
mySerial.println("AT+CREG?"); //Check whether it has registered in the network
updateSerial();
mySerial.println("AT+COPS?"); //Get the module name and revision
updateSerial();
mySerial.println("AT+COPS=3,2,\"23430\"");
updateSerial();
mySerial.println("AT+COPS=?"); //Get the module name and revision
updateSerial();
}
void loop()
{
updateSerial();
}
void updateSerial()
{
delay(500);
while (Serial.available())
{
mySerial.write(Serial.read());//Forward what Serial received to Software Serial Port
}
while(mySerial.available())
{
Serial.write(mySerial.read());//Forward what Software Serial received to Serial Port
}
}
Reason I'm now trying to manual registration route is because it still wasn't connecting automatically. The one I was trying to select was T-Mobile since that's available (the sim card is a vodafone simcard though... i did have a giffgaff one but i'm trying another). Both are registered.
The only variation from the original page is I am using an 18650 for power.
Reason I'm now trying to manual registration route is because it still wasn't connecting automatically. The one I was trying to select was T-Mobile since that's available (the sim card is a vodafone simcard though... i did have a giffgaff one but i'm trying another). Both are registered.
Is the vodafone or giff gaff sim authorized to connect to the T-Mobile network?
I'm not entirely sure if they are authorized. What I don't understand is how it is only picking up t-mobile as a network... and not vodafone, giffgaff, or anything else....
I don't know if 2G is available. It's a normal SIM card you use with a smartphone so... i'm not sure how i can check it...
As stated previously, this is not an Arduino problem, and the knowledge within this community to solve a cross network sim registration issue may be limited.
That certainly is the case for me, and I have no ideas what to do next.
Thanks, so long as no one seems to think it might be a power issue of some sort. I've measured everything using a multimeter and the voltages across the Rx and other pins seems fine... thanks for your input though
