No miso No mosi?


How to connect SPI memory to the Module?
No miso No mosi??? :cry:


see also: (same question, multiple posts)


I agree dear because i want this very badly and it seems the forum is quire dorment

But do you know how to connect 4 wire SPI memory to this three wire SPI
should i short MISO and MOSI of slave device


Sorry, no, I have no idea for that…

Best Regards,


Hi kapilsinghi,

Although I am not an expert in interfacing the hardware, but I can tell you that in Wavecom Wireless CPU the MISO and MOSI signals are mutiplexed.
You can either write or read from the SPI bus but not at the same time.

Hence, the devices, which act as shift register and read and write at same time cannot be used with this configuration (I suppose so). However, for device like flash memories (which are interfaced with SPI) or camera devices, you can send the data and then read it back (as the read/write is not done simultaneously).

Feedback from other forum members is also solicited here.

Best Regards,
Open AT Fan.


In the Customer Design Guideline of New Q24 series there is a chapter that explain how to connect a 4 wires SPI device.
This should be also applicable to Q2501.