SIMCOM SIM800H change in hardware. S2-105HG / S2-10651 , S2-1065N / S2-1065Q

SIMCOM has updated the hardware of SIM800H modules with hardware versions (S2-105HG / S2-10651) due to the fact that the power amplifier chip that these modules used (RF7176) is discontinued from production line. The Firmware also had to be changed due to modifications necessary for operation of the new power amplifier chips.

All the new modules ( with hardware versions(S2-1065N / S2-1065Q) ) will be having the new power amplifier chips namely RF7198. According to SIMCOM this change in hardware wont affect the properties and characteristics of the module.

Please note that:

  • firmware for the new hardware version of module differs from the old version of the firmware. Therefore, a new hardware version module can not be flashed with the firmware for the old hardware version module.
  • firmware image files for the old and new hardware versions will be with different names. Firmware for the old version is designated “1308B06SIM800H32_BT” while the firmware for the new version is designated “1309B06SIM800H32_BT”.


Firmware files for SIM800H

All the firmware files can be found at the firmware collection page of this blog. If you want to contribute the files you have you can do so by uploading your files to user uploads section or by emailing me the files you have.




Sim800H EAGLE library / footprint

SIM800H is a complete Quad-band GSM/GPRS solution in a LGA type which can be embedded in the customer applications.
SIM800H support Quad-band 850/900/1800/1900MHz, it can transmit Voice, SMS and data information with low power consumption. With tiny size of 15.8*17.8*2.4 mm, it can fit into slim and compact demands of customer design.  Featuring Bluetooth, FM and Embedded AT, it allows total cost savings and fast time-to-market for customer applications.




Product details

Download Library for Eagle Cadsoft


Disable PIN code using Gsm modem AT commands

If you have a PIN code enabled SIM card and want to remove /disable PIN code using AT commands follow these commands,
suppose 9546 is the current PIN code , Replace 9546 with your PIN code, >>> shows the response from modem.

>>> +CPIN: SIM PIN // pin codes need to be entered
>>> OK

>>>; OK

AT+CLCK="SC",0,"9546" // disable pin code
>>> OK




GSM Modem/Module not responding to AT commands after firmware Upgrade??

I get a lot of queries about this issue, so I thought I should write a small post about it. For example the latest one was

Hello Muhammad,
I recently update SIM900 to firmware 1137B12SIM900M64_ST.cla using “Simcom – sim900 Customer flash loader V1.01″ at the baud rate 1498000. Everything went perfectly like but after I restart the module I get “þIIIIþþþ” response from SIM900 at 115200 baud rate, I could not get any AT commands working. Kindly do help me.

Some modems support AutoBaud by default. Auto Baud feature allows the modem to be used with any baud rate, and for this to be used the Modem waits for a input string “ATr” it uses this string to detect the baud rate being used. As the manual describes the modem when in Auto Baud will be looking for this string after it is powered and this should be in CAPS otherwise modem wont be able to detect the correct baud rate. Sim900 has the auto baud by default. Some modems don not support Auto Baud so for these modems after the firmware has been updated, you should use the default baud rate, 9600 and 115200 are the most common.

if you want to fix or change the baud rate you should use the AT+IPR command. For example if you need to fix it to 4800.