sim900 only responds to AT commands when empty sketch is uploaded - arduino

I am using a gsm sim900 shield connected to an Arduino uno for my project. The Sim900 only responds to AT commands when I upload an empty sketch to the Arduino. If I put any AT command code in the sketch, the sim900 just echoes the AT commands without giving any response. What could be the problem?

with the information you gave I can throw a guess and say that you don't write at the end of the AT command "\r\n".

Related

ESP8266 ESP-01 not show data from server in Arduino IDE serial monitor

i am new in arduino and ESP8266 module AT commands. I still learn about how to receive data from server and it show the data in Arduino serial monitor. I will tell you how i do and i hope someone will tell me what's wrong with my code or if any mistake that i have done.
This is my php code in server side. Just a simple coding. I save it as index.php :
<?php
ECHO $_GET['subject'];
?>
This is my AT commands in Arduino IDE serial monitor.
AT+CIPSTART="TCP","nyalalampu.atwebpages.com",80
CONNECT
OK
AT+CIPSEND=110
OK
> CLOSED
After this > symbol appear i insert
GET nyalalampu.atwebpages.com/?subject=anis HTTP/1.0
After that i hit Enter button on keyboard.
I don't know why I don't see any data or text in serial monitor after i hit Enter button on keyboard. It's like nothing happen.After a few seconds what i can see just CLOSED message in Arduino IDE serial monitor. Why it don't print anis in Arduino IDE serial monitor just like i send in GET request to server?
I hope someone will show me somelight what mistake that i have done.TQ

FTDI + ESP8266 [Need to use AT Commands] without Arduino

I am trying to write standalone ESP8266 code so that it can communicate to wifi and change its states. For this, what I want to do is to send some command "AT+CWMODE=1" or "AT+CWMODE=3" to ESP8266 via code and toggle them on push button tap.
So, like in Arduino there is a Serial.write which writes on a serial monitor via SoftwareSerial class.
But when I am sending Serial.write("AT+CWMODE=1") it prints on the monitor as a string rather than changing the wifi state.
Is there a way to send AT commands without using Arduino chip software serial pins?
Thanks.
Sorted out the issue. All those who are new like me to ESP world, I did the serial.write "AT" commands using wifi classes of Esp8266.
You need to connect the board as ESP8266 Generic Module and send/receive data using ESP8266Wifi class, by reading the scanned networks, changing mode, using Serial.read on the connected devices on Access point of Esp8266.
Let me know if someone need help on this future, I will be happy to help.

Arduino connected via TCP using SIM900 to Dweet.io

I am trying to stream some sensor data to Dweet.io using my Arduino connected to a SIM900 GSM/GPRS module. I am able to access internet, load data, check GPRS connectivity etc from my Arduino board. Could someone specifically tell me the syntax to post data onto dweet.io?
Instead of Using the AT commands use this library its easier and Nice https://github.com/amcewen/HttpClient
Dweet.io needs GET commands to send and receive data.

ESP8266 Wifi Module - prints "ready" but not responding to AT commands

Just received my first ESP8266 wifi module with some excitement. However I've been unable to fully communicate with it. I have connected the module to my computer via a usb to serial cable and I'm power the module via a separate power supply (3.3v).
After powering the module up I receive the following information (via PuTTY or and Arduino serial monitor window):
[Vendor:www.ai-thinker.com Version:0.9.2.4]
ready
I have tried sending various AT commands e.g.
AT+RST
But I get no response. Using ctrl+m and ctrl+j in putty didn't help either.
Please see my youtube video if its helpful:
https://www.youtube.com/watch?v=RvasOuHuWDc
To get AT OK .
1.AT + PRESS ENTER + THEN CTRL +J WILL GIVE OK
2.Then Enter commands to execute
eg AT+GMR ->presss enter then ctrl+j
to get firmware
repeat step 1 for each command.
Make sure that you have putty or the Arduino serial console configured to send both a newline \n and a carriage return \r character. So AT+RST actually ends up being AT+RST\r\n. This took me a bit when I first received my ESP8266 modules. On the Arduino serial console this option is at the bottom of the window. I can see in your video you have it set to no line ending. Hopefully that does it for you.

Arduino Yun WifiStatus Example Failing

I am able to connect and upload the WifiStatus example per the instructions on the Arduino Site/Examples/Yun. However, when I hit the serial monitor button it is supposed to print out the relevant Wifi stats, instead it says "unable to connect" and the final line goes a bit further..."unable to connect: is the sketch using the bridge". Any ideas? A post suggested reseting the 32U4, which I did, but no luck.
Incidently, all of this is over Wifi. Board and port are set per instructions. Yun pings fine and receives the uploaded sketch fine.
More code is usually more illuminating... so you might get better answers when you provide more information.
"is the sketch using the bridge" seems to indicate that there is some problem with the Bridge library. Is it being initialized? Did initialization (i.e., "Bridge.begin()" succeed?
A sketch with bridge functional and serial monitor via network connection cannot be running simultaneously as they use the same hardware connection.
You may use the serial monitor via USB port, or Serial TX/RX pins, or SoftwareSerial for this.

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