setMOSI (et. al) on Teensy 3.6?

[rhyde]

I'm trying to move the SPI calls to the MOSI2, MISO2, and SCK2 pins on the Teensy 3.6:

#define SPICS 43
#define MOSI 44
#define MISO 45
#define SCK 46

SPISettings WeensySPI( 2000000, MSBFIRST, SPI_MODE0 );

In setup:

pinMode( SPICS, OUTPUT );
digitalWrite( SPICS, 1 );
SPI.begin();
SPI.setMOSI( MOSI );
SPI.setMISO( MISO );
SPI.setSCK( SCK );

In Loop:
SPI.beginTransaction( WeensySPI );
digitalWrite( SPICS, 0 );

// Only writing, incoming data is ignored:

SPI.transfer( bits >> 8 );
SPI.transfer( bits & 0xff );

digitalWrite( SPICS, 1 );
SPI.endTransaction();


It's still accessing the SPI 0 pins.
Am I doing something wrong here?
Thanks,
Randy Hyde

 

[Frank B]

Try SPI2.begin ... and so on

 

[rhyde]

Thanks, that did the trick.

 

[WMXZ]

Try SPI2.begin ... and so on

to add to Frank's suggestion:
when using Begin/EndTransactions, don't set CS manually but use "setCS(pin)". The transaction functions handles then everything for you.

 

[KurtE]

to add to Frank's suggestion:
when using Begin/EndTransactions, don't set CS manually but use "setCS(pin)". The transaction functions handles then everything for you.

I could be completely out to lunch, but does that work when using standard functions like SPI2.transfer?

For example as far as I know endTransaction only does something if you are using InterruptMode....

My understanding and usage of setCS is, yes it does switch that pin into a SPI cs pin and it returns a mask for the channel that the CS that pin is on.

You can encode which of the CS channels to use when you push a command onto the FIFO queue.

Example with ILI9341_t3 library, we have code that at init time calls setCS twice, once for the CS and another for the DC.

	if (SPI.pinIsChipSelect(_cs, _dc)) {
		pcs_data = SPI.setCS(_cs);
		pcs_command = pcs_data | SPI.setCS(_dc);
	} else {

Later when we push a command that will also keep CS asserted, and touches both CS and DC, the code generates the command like:

		KINETISK_SPI0.PUSHR = c | (pcs_command << 16) | SPI_PUSHR_CTAS(0) | SPI_PUSHR_CONT;

Where "c" is the command byte, pcs_command has the encoding for both CS and DC, and the SPI_... are defines in the kinetis.h file.

Again as far as I know there is nothing in begin/endTransaction that uses these? But again I may be missing it.

 

[rhyde]

Someone ought to update this page: https://www.pjrc.com/teensy/td_libs_SPI.html to reflect reality.

On a similar topic, what's the trick to accessing different I2C ports? Wire3.begin() doesn't work and the Teensy I2C page doesn't mention anything.
(also, is i2c_t3-master really limited to using the extra I2C ports as slaves?)


**Edit**
Nevermind, I loaded i2c_t3 and despite what I read it seems to work.