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bobspam@free.fr
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Last seen: 1 year 7 months ago
Joined: 2018-06-20 08:07
AD1468x - SPI Half Duplex

Hello

I do need to communicate with a SPI peripheral that requires SPI Half-Duplex communications.

Can you confirm to me that this is possible with AD1468x and how ?

Is complex SPI transaction with callback functions between read and write transactions in which we toggle GPIO PIN Function from DO to DI suitable ?

Thank you in advance

 

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PM_Dialog
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Last seen: 7 months 1 week ago
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Joined: 2018-02-08 11:03
If I understood correctly,

If I understood correctly, you would like to have 3-wire SPI instead of 4-wire SPI. Is that correct? If yes, you could do something like the attached photo. Resistor value is dependent on pad strength and voltage level. You need to ensure that the Vhigh is well above Threshold.  Resistor in conjunction with capacitances of pads and pcb create a low pass filter. The higher the Resistor, the longer rise and fall times. 1K to 10K can be tried based on the speed. If you mean the ad_spi_complex_transact() API this is used in full duplex mode. In general, the DA1468x supports full duplex mode, but if you would like to connect a peripheral which supports half duplex, you could do the procedure I described. In addition, I would strongly recommend you to have a look at SPI Adapter Concept tutorial as well.

Thanks, PM_Dialog

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