make logic trigger on rising edge of a bit

I'm trying to write a HAL component to provide the logic that my PWM brush servo amps
need to come out of their disabled state. They need a small PWM pulse in each direction.
I have this logic built into the HAL driver for my PWM controller board, but some people
want to use these amps with Mesa controllers.

So, I followed the logic in the hal component flipflop.comp but I can't get it to
trigger. The state variable stays at two, even though I can see the
delayed version of the enable lagging the enable input by one
servo cycle.

I posted my component boot.hal at
pico-systems.com/codes/boot.comp

The specific problem is at line 24, the first if statement.
If it recognizes enable is 1 but the old copy of enable is
0, then it should set newstate to 0, but it appears it
does not. Anybody have any ideas?

Thanks,

Jon

Hi Jon

I can't really test it at present, but I think it is down to when and where your struct is declared.

The C code shows a void pointer _data being included into struct _comp_state{} and a #define being created
#undef data
#define data (*(boot_data*)(__comp_inst->_data))

but the pointer is never set to the boot_data struct which is only declared after this.

If you substitute 2 variables (option data is now deprecated anyway) as per the attached, the actual variables become part of struct _comp_state{}
rather than an uninitialised pointer to a struct containing them.

regards

ArcEye wrote:

Hi Jon

I can't really test it at present, but I think it is down to when and where your struct is declared.

The C code shows a void pointer _data being included into struct _comp_state{} and a #define being created
#undef data
#define data (*(boot_data*)(__comp_inst->_data))

but the pointer is never set to the boot_data struct which is only declared after this.

/quote]
Thanks, that explains it! The oldenable was not being saved. I copied this code from
flipflop.comp, which is quite old. I likely put a line in the wrong place.
Later I wored on it some more and got
it to work by copying syntax from some newer comps.

Jon