Anas

lately, I was designing a GSM/GPRS Module based on SIMCom SIM800, Something like SIM800L Coreboard.

For some reason, my employer was not able to get this module and we were not very happy with this crude design.

So what do we want in the module?

• Rigorous design, SIM800L Core board almost has no components, we added all recommended parts.
• Solid protection scheme (ESD, Overvoltage).
• UART Compatibility with TTL and 3.3 voltage levels, we wanted the module to be able to communicate directly with any microcontroller.

Having that in mind, I started the design process that started with reading SIM800 datasheet, SIMCOM calls it Hardware Design, and I can tell this wasn’t very fun, The document is not always clear and I had to consult other products like the SIM900 datasheet to be sure about the meaning of a certain recommendation, in short, follow what they recommend even if it seems laborious for no reason. After that things went more smooth.

Assembling the prototype board by hand wasn’t hard.

The module worked as intended, so thankfully no changes will be made to the design, below is a top and bottom view of the design.

UPDATE 01

I’ve decided to share the source of the board here both the schematic and the PCB, it may be useful as a reference for someone, you can find the resources in the following link.