A problem with the SIM900 module I want to connect to an STM32F4
Hello everyone, I have a weird problem. At my internship, I was given a SIM900 and SIM7600 module and told to make projects based on them, yet I cannot find these modules anywhere on the internet. The project I wish to do with the SIM900 is thus: Send an SMS to my phone. Here is the SIM900 module I was given:

Here is the SIM7600 module, which is approx. the same:

I have decided that the best course of action from this point onwards would be to try to use the pins of the chip itself to suit my needs. That is fine. What strikes me as odd is that I cannot, for the life of me, find these things anywhere. Are there any alternate sources I can try? I wrote the numbers on the cards into Google, I did Google reverse search, I tried to read the pins and figure out any distinct features but the SD card is the only one I can think of--which led me nowhere new.
Is my research simply insufficient? Thank you for your time.


