Detecting positive edge
Archiver
Posts: 46,084
Your Stamp probably isn't the right tool to reach for when trying to
reliably detect edges/short pulses, or generate a continuous pulse
train. I built myself a Stamp accessory for these purposes. See
the Pulse Machine info at:
http://home.earthlink.net/~parkiss/
In particular, I believe the "latch pulse" and "clock generator"
commands, under Stamp control, will do what you're after. Here's a
simple example using the latch pulse command and two Stamp pins:
SEROUT pulsex_pin,out_baud,[noparse][[/noparse]$0c] 'latch pulse input
await:
IF pulseout_pin = 1 THEN await 'check "latched" status
Here's an example of generating a 4 usec period clock (2 usec low, 2
usec high) off the PM-1 pulseout pin:
SEROUT pulsex_pin,out_baud,[noparse][[/noparse]$06,0,0,0,2,0,0,0,2]
You can define the clock generator's duty cycle and clock period as
desired.
The PM-1 has several other pulse functions and a simple LCD
interface as well. You can build your own from the provided source
code or contact me off-list if you'd like to purchase a programmed
chip.
Steve
On 14 Sep 00 at 13:45, pwang@d... wrote:
> HI, everone,
> Can I use BS2 to detect positive going edge of a pulse
> input to BS2, or do I need to use external TTL cricuit
> to do that?
> Currently, I need to detect pulse edge of every pulse
> coming itno BS2.
>
> * Is it OK, if I just detect the pulse at 5V level?
>
> topline:
> if IN1 then isSTART
> goto topline
>
> isSTART:
> 5V level detected.
>
> but BS2 takes some time to execute the topline: loop, I
> might miss a pulse.
>
> Thanks,
> wang
reliably detect edges/short pulses, or generate a continuous pulse
train. I built myself a Stamp accessory for these purposes. See
the Pulse Machine info at:
http://home.earthlink.net/~parkiss/
In particular, I believe the "latch pulse" and "clock generator"
commands, under Stamp control, will do what you're after. Here's a
simple example using the latch pulse command and two Stamp pins:
SEROUT pulsex_pin,out_baud,[noparse][[/noparse]$0c] 'latch pulse input
await:
IF pulseout_pin = 1 THEN await 'check "latched" status
Here's an example of generating a 4 usec period clock (2 usec low, 2
usec high) off the PM-1 pulseout pin:
SEROUT pulsex_pin,out_baud,[noparse][[/noparse]$06,0,0,0,2,0,0,0,2]
You can define the clock generator's duty cycle and clock period as
desired.
The PM-1 has several other pulse functions and a simple LCD
interface as well. You can build your own from the provided source
code or contact me off-list if you'd like to purchase a programmed
chip.
Steve
On 14 Sep 00 at 13:45, pwang@d... wrote:
> HI, everone,
> Can I use BS2 to detect positive going edge of a pulse
> input to BS2, or do I need to use external TTL cricuit
> to do that?
> Currently, I need to detect pulse edge of every pulse
> coming itno BS2.
>
> * Is it OK, if I just detect the pulse at 5V level?
>
> topline:
> if IN1 then isSTART
> goto topline
>
> isSTART:
> 5V level detected.
>
> but BS2 takes some time to execute the topline: loop, I
> might miss a pulse.
>
> Thanks,
> wang
Comments
Can I use BS2 to detect positive going edge of a pulse
input to BS2, or do I need to use external TTL cricuit
to do that?
Currently, I need to detect pulse edge of every pulse
coming itno BS2.
* Is it OK, if I just detect the pulse at 5V level?
topline:
if IN1 then isSTART
goto topline
isSTART:
5V level detected.
but BS2 takes some time to execute the topline: loop, I
might miss a pulse.
Thanks,
wang
pwang@d... writes:
> topline:
> if IN1 then isSTART
> goto topline
>
> isSTART:
> 5V level detected.
>
> but BS2 takes some time to execute the topline: loop, I
> might miss a pulse.
You can use PULSIN to detect fast pulses -- so long as there isn't more thatn
131 ms between them.