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Use SPI and I2C at the same time on WiPy 3.0

Posted: Wed Jan 23, 2019 1:35 pm
by foxinbox
For my project I've to use WiPy 3.0 with expansion board, as3993 rfid reader and MPU9250 sensor. For the Mpu9250 sensor I use I2C interface with default pins P10 and P11 for SDA and SCL respectively. But for as3993 reader I've to use SPI interface, because it supports only this interface. And the reader requires following pins: MOSI, MISO, IRQ, SCLK(CLK), NCS (CS), CLSYS. If MOSI, MISO, SCLK pins are known as P11, P14, P10, but about IRQ, NCS (CS), CLSYS pins i cant find information. Should I assign these pins by myself or are they already defined on the board itself? As datasheet i use it:

As well, will it possible to use at the same time I2C and SPI interfaces if they use the same pins or should I assign another pins?

Re: Use SPI and I2C at the same time on WiPy 3.0

Posted: Wed Jan 23, 2019 1:48 pm
by Roberthh
This is the wrong forum. For WiPy3 go to
But about your questions:
No: You cannot use I2C and SPI on the same pins. They must be different.
Yes: You can assign I2C and SPI to any available pin. There are some restrictions. Some pins are input only. So you can use them for MISO (like P14), but not for MOSI and not for SDA or SCL. You should not use P0, P1 and P12. If you use the SC card, P4, P8 and P23 are also not available. P2 must not have a pull-down at boot time, but can be used further on, like for SDA and SCL.