The life of components in electronics can also come to an end. So is true about SIM900 GSM modem that is part of GW version 1.7. Although it is still available online, officially it is not recommended for new development, and local distributors have no longer any in stock. The decision had come to choose new GSM module. As SIMCom modules have proven to be reliable at good price, I had in mind to switch over to some of their new model. Put it simple SIM800C was chosen to be a replacement. It is still 2G modem with four band GSM support and can be deployed worldwide. Fortunately there is no difference in AT command set that is used by gateway firmware, so the new boards are interchangeable in terms of code. There seems to be interest in 3G modem of OHS gateway users that are located in U.S.A., but for now we stay at 2G (3G module is 4x expensive then 2G, and 3G band are varying across regions. But if there will be interest, I will design new version of gateway with possibility to mount 3G or 2G module).

New boards have also same footprint and connectors location have not changed, except for SIM card holder and GSM antenna connector. They are named 1.7C and come in blue colour with round edges similar to new nodes.

P.S. Picture will come soon :)

Link to blog.