Update SIM900 to SIM800F in Your IOT Project

Update SIM900 to SIM800F in Your IOT Project

July 04, 2019

Update SIM900 to SIM800F in Your IOT Project

There the SIM900 GPRS/GPS module is popular used in IOT projects, but as the SIM900 module is EOL, if you find them on sell in the market, the price is high. So there plenty of projects need to be updated.
Update SIM900 Project to SIM800F
As the producer SIMCom suggestion, the SIM800F is pin-to-pin upgrade version for the SIM900. But if you indeed solder the SIM800F module directly on the boards that previous works with SIM900, there high possibility that, the SIM800F do not work.

That is, the SIM800F is not fully compatible with the SIM900!

Compares the pins definition:
SIM800F(Top View) PIN DefinitionSIM900(Top View) PIN Definition
                         
 (SIM800F Top View)                                                 (SIM900 Top View)

There the most significant difference is: 
The Pins differences between SIM800F and SIM900

That is:
1. (mandatory)For SIM900, the Pin_2 can be NC , but if using SIM800F, it should be GND connected, or the SIM800F will not work.
2. (Optional)For SIM900, the Pin_23 NC, but Pin_23 can be KPLED control for SIM800F.
3.(Optional) For SIM900, the Pin_24 NC, but Pin_23 can be VBUS
4. (Optional) Pin_27/28 different definition, from UART to USB;
5. (mandatory) for SIM900, PIN_53 need to be GND connected, while for SIM800F, it is BT-ant, or NC is not used.

To make the SIM800F work as SIM900 substitute item, these 2 pins need to be updated:
2 pins of SIM800F need to be updated

With these 2 hardware modification, the SIM800F works with GPRS/GPS connections.

In SIMCom+ MCU usage, with AT commands, there also some AT commands difference, please check
this.