RAM and UART Buffer size of SIM800L

Hi Ravi,

How can I find out the RAM size and UART buffer size of GSM SIM800L module?

I have read the datasheet but i coud not find the information anywhere.


Hi Anuvandan,

I don’t know how you can do that. Why would you need that?
But you can find the buffer size of HTTP post request using command AT+HTTPDATA?

Thanks for the reply Ravi.

I was trying to send lot of data using GET request. I used HTTPPARA command to give the URL and the corresponding data. The data i was trying to send was around 500 bytes. But I do not receive the data in my database. That is why I thought, is the UART buffer at GSM side overflowing??

Or is the reason something else? Will using POST request using AT+HTTPDATA solve it?

Please let me know if the question is not clear.


Yes, GET request has limits. HTTP post is better for longer data.

Thank you so much for the help Ravi. Will try it with POST request and check if it works.

Hi Ravi,

As per your suggestion, I tried to do POST request to send longer data. However I am facing problems in doing the same. I am running the arduino code with following sequence of commands to make the request. However in my database, I do not see any data but the rows get incrementing one by one.

I have also tried just to send the string “hello” in order to be sure of the length of data. Please find the code below. Not posting the whole code as other things are similar as of GET request:


Please let me know if the question is not clear.