interface msp430 with cc3000wifi via SPI

[tuong]

Hello all,
I am using msp430f249 MCU to interface with cc3000mod TI and I had a problem when initiating start cc3000 via SPI.
when I sent first write command to start cc3000 wifi , but cc3000 response wrong data.

from msp430 to cc3000 command: 01 00 05 00 00 01 00 40 01 00 . I sent right command on TXbuffer register.
from cc3000 to msp430 command:  I received : {02}{00}{FF}{00}û{00}{00}{00}{00}û (wrong received data) instead of 02 00 00 00 05 04 00 40 01 00 (right data). Only first two bytes are true 0x02,0x00 and otherwise is false.
there are 5 connected pins, SPI_CS,SPI_Din,SPI_Dout, SPI_CLK, SPI_INT.
Personally, I think that signals did not completely transmit to cc3000, so it didn’t response right data. I pay attention to 2 pins SPI_CLK and SPI_Dout because it transmits data to cc3000. I get feedback someone say that it didn’t match impedance but I don’t know how much impedance or capacitor, resistor, inductor should add?. I am not electrical profession, so it is difficult to solve it. Someone can help cope with this situation, hopely?
Thank you so much
regards
Tuong

[AJISH ALFRED]

Hi tuong,

If your are not an electrical profession, you must have find this project from a website or book. Is there any link or any other means by which we can learn more about this project and help you better?

[tuong]

You can help me about matching impedance between MCU and CC3000 wifi. I figured out some document on website and knew what matching impedance?. In my ideas, I will measure output impedance from host and input impedance from slave. You think it is right?

 

[AJISH ALFRED]

Hi Tuong,

I read this datasheet of your Wifi module

http://www.ti.com/lit/ds/swrs126/swrs126.pdf

 

It can be simply interfaced to the SPI port of the microcontroller just like any other SPI device. 

SPI is a kind of digital interface method and there is no need to consider the impedance and all.

[tuong]

You are right but cc3000 did not receive right data, so it did not response approriate sequence of bytes to msp430.

Hence, transmission line got problem. Do you agree with me?

[AJISH ALFRED]

Hi Tuong,

The SPI standard specifies the details of the transmission lines also. Suggest you to do a good research on it and find whether the transmission lines that you use matches with the SPI specifications.

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