On 3/9/2014 8:37 PM, Manu wrote: > I was trying a few days to enable PRU (BBB Ubuntu 12.04) and run a input > testing code using the pin P9_24. > > MUX = pin 97 (44e10984) 00000006 pinctrl-single (SET to MODE 6) > > P9 24 pr1_pru0_pru_r31_16.GPIO0_15: | MODE6 | INPUT > > Nothing happens when I put the pin to 1.8 or GND
You have to enable the pin's input buffer: https://github.com/cdsteinkuehler/beaglebone-universal-io/blob/master/cape-universal-00A0.dts#L429 > The ASM code is: > > .origin 0 > .entrypoint START > > #define PRU0_ARM_INTERRUPT 19 > #define AM33XX > > #define GPIO1 0x4804c000 > #define GPIO_CLEARDATAOUT 0x190 > #define GPIO_SETDATAOUT 0x194 > > START: > // clear that bit > LBCO r0, C4, 4, 4 > CLR r0, r0, 4 > SBCO r0, C4, 4, 4 > > MOV r0, 1000000000 //# cycles > > INPUTTEST: > > WBS r31.t15 //Wait til GPIO-15-in is high... P9_24 > SUB r0, r0, 1 //Subtract from counter > QBNE INPUTTEST, r0, 0 //Loop if counter not at zero > // Send notification to Host for program completion > MOV R31.b0, PRU0_ARM_INTERRUPT+16 > > MOV r0, 0 > HALT > > I don't know what I am doing wrong and in Internet are not examples for > INPUT tests. Your code looks OK. Here's a known working example that uses the PRU direct inputs to implement a PRU software based encoder interface: https://github.com/cdsteinkuehler/linuxcnc/blob/WIP-pru-cleanup/src/hal/drivers/hal_pru_generic/pru_encoder.p ...it's not the easiest code to use as a reference, since it relies on my universal overlay (to setup proper pin multiplexing), and ARM code (to setup and configure the look-up tables to do counting, see encoder.c in the same directory), but perhaps it will be of some help. -- Charles Steinkuehler char...@steinkuehler.net -- 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 beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
