Wismo218 Main Serial how-to

I tried to send AT commands to WISMO218, but i didn’'t receive any “OK” or other response.
Can you tell me if the WISMO218 works with autobaud at initial setup ?
I don’t have seen any comment in the datasheet about baud rate, parity, # of bits …
Thank you so much if you can give me more infos.


Hi Rudy,

Do you know which firmware version are running on your WISMO218 module?

Have you read the AT command manual for WS series?
Under Auto-Band (+IPR=0), it writes:

the capital letter A must be entered to detect the DTE baud rate.
all AT commands must be in capital letters.

Please try to send “AT” as first command to allow rate detection if you have not done so.
Hope it helps.

Dear Lotham,

Thank you for your help,

I tried to sent “AT”> and waiting receive “OK” at 19200 but without success.
To pass throught i do this :
115200 Bauds: “AT+IPR=19200”, switch to 19200 and at commands respond.

Now all AT commands works EXEPT 2 MAJORS COMMANDS :

“ATD” & “AT+CMGS=…”

if i send:

i receive the invite

i send:
this is my message

and … nothing happend ! (CTRL-Z is HEX 1A)

But i can well receive SMS with AT+CMGL command !

I do something wrong but what ?

Problem found !

SIM Cards from BASE does’nt work to send SMS nor ATD commands

Sim Cards from Mobistar work without problem.

I hope that Sierra Wireless will take care about this problem because we have spent a lot of time in dev !


What FW version your WISMO218 is running?
Can you try and send below and share the response?

ATDxxxx; (try to make a call here)


Dear Lotam,

Firmware is :
L02_00gg.WISMO218 150409

i can receive sms and read them with AT+CMGL=“ALL” but i cannot send with AT+CMGS, and this only with BASE operator, with another operator it works fine.

another problem is that i cannot upgrade the firmware, i have contacted my distributor to have samples with last firmware release.

But another question : i tested AT*PSSTKI=2 and module return me ERROR, i have choice only between 0 and 1. Why asking me this command ?

Best regards,


L02 doesn’t support ATPSSTKI=2.
Some SIM cards have STK app which run on power-up. It would display some message on UART and expect a response. AT
PSSTKI=2 sends an auto response to some STK commands (see AT manual for more details). If this response isn’t sent, the module is blocked and ATD would fail. I am not sure if disabling it with AT*PSSTKI=0 would help, but it is worth a try.

I have the same problem.
My architecture is the following: wismo218 connected to renesas h836064 Serial Control Interface (SCI) as suggestied by the user guide (Document 4111957 Rev 8.1 February 22, 2012 pag. 39 Figure Number 8: two wire connection)
We build some pieces of oru board, some if them work and some don’t, and what I see is that they don’t answer to AT command.
How can I debug?
What is the exact procedure to make the auto baudrate?


FABIO Giovagnini

I found that WISMO218 can be set at 9600 bps or 115200 bps.
The connection with 2 wire according the manual is fine.
The previous suggestion are good. They work.

Best regards