Multiple devices on the same SPI bus but with different SPI configs

[jean_prieur]

Posted on June 17, 2013 at 10:37

Hello,

I use the STM32F407 and I have to link 3 different slave devices on the same SPI bus (an accelerometer, a touchpad controller and a screen). I have no other solutions. Each device is activated with chip select pin (CS).The problem is, devices have not the same SPI configuration, for example the accelerometer is driven by a clock at high level by default and the touchpad controller is driven by a clock at low level.Does anyone has already used SPI with different configurations ? Can I change the SPI config each time I want to drive a device ?Thanks for your advice !Jean

[jean_prieur]

Posted on June 18, 2013 at 11:59

It seems complicated to have something working well and fast. I think I need to change one of my device and make it I2C compatible. 

I was thinking SPI is a standard protocol and it's easy to link a lot of ICs but it's not !Anyway thanks for your interesting solutions.

[frankmeyer9]

Posted on June 18, 2013 at 13:20

It is hard for others to really estimate all requirements in context - so this is up to you.

You can build a prototype around some core functionality to prove your design, but this costs time, too. Another idea - you could discard the internal DAC and use the GPIO pins for SPI instead. There are plenty of serial DAC circuits around ...