BeagleBone adaptor panics when trying to use direct pin

[trevrosen]

Hi there,
I am getting an index out of range panic when trying to use a direct pin driver with a BeagleBone adaptor. Below is a minimal repro case as well as some system information. It should be noted that the repro case here is very similar to the provided BB direct pin example at https://github.com/hybridgroup/gobot/blob/master/examples/beaglebone_direct_pin.go

Repro script

package main
import(
        _"github.com/hybridgroup/gobot"
        "github.com/hybridgroup/gobot/platforms/beaglebone"
        "github.com/hybridgroup/gobot/platforms/gpio"
)

func main() {
        beagleboneAdaptor := beaglebone.NewBeagleboneAdaptor("testbox")
        gpioPin           := gpio.NewDirectPinDriver(beagleboneAdaptor, "mahDevice", "P9_12")
        gpioPin.DigitalWrite(1)
}

Stack trace:

root@beaglebone:~/go/src/bbb_test# ./bbb_test
panic: runtime error: index out of range

goroutine 16 [running]:
runtime.panic(0x103658, 0x1a3264)
    /usr/local/go/src/pkg/runtime/panic.c:279 +0x1a0
github.com/hybridgroup/gobot/platforms/beaglebone.(*BeagleboneAdaptor).digitalPin(0x1032e080, 0x110fb8, 0x5, 0x10fde8, 0x1, 0xb6fc8370)
    /root/go/src/github.com/hybridgroup/gobot/platforms/beaglebone/beaglebone_adaptor.go:237 +0x68
github.com/hybridgroup/gobot/platforms/beaglebone.(*BeagleboneAdaptor).DigitalWrite(0x1032e080, 0x110fb8, 0x5, 0x1)
    /root/go/src/github.com/hybridgroup/gobot/platforms/beaglebone/beaglebone_adaptor.go:174 +0x54
github.com/hybridgroup/gobot/platforms/gpio.(*DirectPinDriver).DigitalWrite(0x10318150, 0x1032e001)
    /root/go/src/github.com/hybridgroup/gobot/platforms/gpio/direct_pin_driver.go:65 +0x88
main.main()
    /root/go/src/bbb_test/main.go:12 +0xd0

System information

root@beaglebone:~/go/src/bbb_test# cat /etc/issue
Debian GNU/Linux 7 \n \l

root@beaglebone:~/go/src/bbb_test# go version
go version go1.3 linux/arm

[trevrosen]

In the spirit of solving my own issue, I have been looking into this. It seems that the digitalPins array has a length of 0 at the time that it is being accessed. Still investigating, but feeling like I'm on the right track.

[trevrosen]

Sorry for thrash on this -- realized that I would need to call Connect(), which I would've known if I'd have rtfm'd harder in the first place. 👍