Yes, I know it's terribly confusing. I alwayus forget myself. The way I
double check is to look at the dtso and see which pin is input.
spi1_pins_s0: spi1_pins_s0 {
pinctrl-single,pins = <
0x190 0x33 /* mcasp0_aclkx.spi1_sclk, INPUT_PULLUP | MODE3 */
0x194 0x33 /* mcasp0_fsx.spi1_d0, INPUT_PULLUP | MODE3 */
0x198 0x13 /* mcasp0_axr0.spi1_d1, OUTPUT_PULLUP | MODE3 */
0x19c 0x13 /* mcasp0_ahclkr.spi1_cs0, OUTPUT_PULLUP | MODE3 */
>;
};
As you can see here, spi1_d0 is input, therefore D0 == MISO, D1 == MOSI.
Cheers,
On 05/11/13 22:43, [email protected] wrote:
> Jack,
>
> Can I read your post to mean that the defaults are:
>
> MOSI <-> SPIx_D0
>
> MISO <-> SPIx_D1
>
>
> in BBB lingo?
>
> The BBB RM is somewhat devoid of SPI information. The TI 3358 reference
> manual (SPRUH73I rev I, August 2013) shows the opposite on pages 4543 to
> 4544, figure 24-1 and table 24-4.
>
> It appears that D0/D1 are configurable. I do not care to configure it. I
> want it to just work the way I wire it, so I want the default. Is D0
> MISO or MOSI by default?
>
> Cheers,
> Joe
>
> On Wednesday, March 21, 2012 5:09:39 AM UTC-4, Jack Mitchell wrote:
>
> Pins 18 and 21 are MISO (Master Input, Slave Output) and MOSI
> (Master Output, Slave Input), what tying them together does it send
> the out from your program, to the input of your program, hence you
> create a loop just reading what you are writing!
>
> Hope that helps clear things up!
>
> Cheers,
>
> --
> Jack Mitchell
> Embedded Systems Engineer
> http://www.embed.me.uk
>
> On Wednesday, 21 March 2012 02:04:49 UTC, emb wrote:
>
> ah, thanks mr mitchell
>
> the step i was missing was tying pins 18 and 21 on P9... i'm
> still not
> sure (from reading BONE_SR.pdf) why this is needed...?
>
> anyways thanks again
> eb
>
> --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to the Google
> Groups "BeagleBoard" group.
> To unsubscribe from this group and stop receiving emails from it, send
> an email to [email protected].
> For more options, visit https://groups.google.com/groups/opt_out.
--
Jack Mitchell ([email protected])
Embedded Systems Engineer
Cambridgeshire, UK
http://www.embed.me.uk
--
--
For more options, visit http://beagleboard.org/discuss
---
You received this message because you are subscribed to the Google Groups
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/groups/opt_out.
