Wireless communication issue

Dear all,

I am working on WiFi module WF43 which is made by Amped RF tech. I have connected the wifi module with my controller. The connections are attached with this.

Now when I send the AT command, it replies me a junk data. Please help me to figure it out. Please ask me if any other detail is required.

Thanking you in advance.

Dear KlauST,

Thanks for your prompt reply.

The baud rate is set as per the data sheet also the V_OH,V_OL,V_IH,V_IL are not creating any issue. Does those RTS and CTS lines on WF43 wifi module shoul be shortcircuited as it is working on UART protocol? Please help.

Hi,

My hint: baudrate mismatch.

Additionally there may be a problem with signal voltage caused by two different supply voltages.
Consider to use level translators.
Read both datasheets: V_OH, V_OL, V_IH, V_IL

Klaus



Hi,

Sorry for the confusion with the order of post#2 and post#3.

*****



Hi,

--> To answer this we need to read the datasheet... Or you read the datasheet.

Klaus

Here is the data sheet, Please suggest on the same:

http://www.ampedrftech.com/datasheet..._Datasheet.pdf

Hi,

there is no information that you can do without flow control.

So if you don′t care about the flow control state you risk loss of data.

Klaus

So shall I short RTS and CTS pins on WF43 module only. As I am not using RTS and CTS pins for microcontroller. Please suggest.

Hi,

If the datasheet is not clear on this, I recommend to contact the manufacturer.
Else we can only guess...

***
I just read the I/O recommendations:
"I/O pin voltage VIO: min -0.3V, max +2.5V"
I wonder why you come to the conclusion that inputing 5V won′t be an issue..

Klaus

Dear Klaus,

The 5V is given to the microcontroller adn 3.3 V gievn to the wf43 module. The grounds are command for both. Does this harm? I think not because I am using this module and its giving me reply "System Power on \r\n-Command mode- MACaddress-00000443d4rf" in responce to the command "at+wf config". But ut shoud give entire configuration of module as a reply.

Hope you understood now.

Dear Klaus,

You are right in all way, its great too. But have you seen the data sheet? They have used level shifter IC on board. This is the reason why I am applying 5V to microcontroller and 3.3 V to the wifi Board. Hope you have understood. But still am not able to find why, I am not getting the correct reply. I am getting reply as "System Power on \r\n-Command mode- MACaddress-00000443d4rf" for all data send even for wrong AT command send. Even if I have send "123456"CR , the same result.

Hi,

5V supply to microcontroller... usually means the signal output at it′s TxD is 5V also.

This signal goes to the RxD of the WiFi module. But this only allowes max 2.5V input voltage. This is out of specification.
For sure this may work (now). But don′t complain if it fails. Today, tomorrow, in a week, or in a year... Nobody knows.

The same is for the output voltage of the WiFi module.
It is min. 2.0V for a HIGH. But is 2.0V enough for the 5V supplied microcontroller? Maybe it is, maybe not. We don′t know.
Again: For sure this may work (now). But don′t complain if it fails. With different ambient temperature, on supply voltage drifts, with an equal microcontroller, with an equal WiFi module...

Klaus



Hi,

No. I didn′t find any information about level shifters.

Klaus

Please see the page number 13.
Its shown in the figure.

Hi,

The picture you refer to is an example circuit how to connect the bluetooth module to an RS232 interface.
It is not on board.
It has nothing to do with (CMOS) level conversion from 5V supplied devices with 3V supplied devices.
The 2.5V input limit of the datasheet is valid.

Klaus