SPI with teensy mod

[Armadafg]

Hi,



This is what i would like to do basically with two teensy mod.

A first teensy mod with an sd card and a bt818 graphics chip.
And the second with another sd card with this faith a wifi and bluetooth module.
This is not a small part of my project, there will be a lot more to connect to these two controllers. But in all cases I need a maximum flow between the two teensy mod, hence the use of the "spi" bus between the two controllers.

I would like to know if it is possible to use both an sd card in qspi mode and the spi1 bus to do other tasks at the same time, even if I know that the data will follow each other and not pass not at the same time.

For the moment I plan to use the i2c bus between the two teensy mods, but it is, if I am not talking nonsense, much slower.

Thank you in advance for your help .

 

[brtaylor]

I would like to know if it is possible to use both an sd card in qspi mode and the spi1 bus to do other tasks at the same time, even if I know that the data will follow each other and not pass not at the same time.

Sure, this is what Teensy 4.1 is doing all the time. I would search the forum - there's been a few threads for getting the Teensy 4.x to operate as an SPI Peripheral / Slave and at least one library to facilitate it (i.e. https://forum.pjrc.com/threads/66389-SPISlave_T4).

I would also consider UART for communicating between the two boards. The software would be much simpler and I think the maximum baud rate would be somewhere around 6 Mb/s (IIRC). You may also want to consider USB or ethernet as potentially faster options too. If it were me, I'd start with the simplest (i.e. UART) and work my way up in complexity if I needed more bandwidth.