So I have a SPLC that's infrequently outputting ~ 100uS positive-goingOne approach would be to hang a parallel RC on one of the comparator's +
pulses on a few pins, and on two of the lines I'd like to stretch that
pulse out to blink an LED for the user to confirm activity.
Here is my nice-to-have constraint, I have four comparators in the
device (GreenPAK) that aren't currently being used for anything.
The non-inverting inputs are on a pin with configurable pull-up/pull-down/float, and the inverting input voltages can be
adjusted, along with selectable hysteresis from a couple low mV-range
values. And the outputs can be configured open-drain or push-pull, and
out to a pin, also with configurable pull-up/pull-down/float.
Unfortunately it's not possible to configure them as inverting so easily
so if this task can be done with just passives and non-inverting comps
with those constraints and put those comps to a purpose, that'd be
awesome, any suggestions appreciated!
So I have a SPLC that's infrequently outputting ~ 100uS positive-going
pulses on a few pins, and on two of the lines I'd like to stretch that
pulse out to blink an LED for the user to confirm activity.
Here is my nice-to-have constraint, I have four comparators in the
device (GreenPAK) that aren't currently being used for anything.
The non-inverting inputs are on a pin with configurable pull-up/pull-down/float, and the inverting input voltages can be
adjusted, along with selectable hysteresis from a couple low mV-range
values. And the outputs can be configured open-drain or push-pull, and
out to a pin, also with configurable pull-up/pull-down/float.
Unfortunately it's not possible to configure them as inverting so easily
so if this task can be done with just passives and non-inverting comps
with those constraints and put those comps to a purpose, that'd be
awesome, any suggestions appreciated!
On 2023-11-28 14:46, bitrex wrote:
So I have a SPLC that's infrequently outputting ~ 100uS positive-goingOne approach would be to hang a parallel RC on one of the comparator's + input pin, drive the LED from its output to ground, and turn it on by transiently pulling the input high (use a second tristate pin if you
pulses on a few pins, and on two of the lines I'd like to stretch that
pulse out to blink an LED for the user to confirm activity.
Here is my nice-to-have constraint, I have four comparators in the
device (GreenPAK) that aren't currently being used for anything.
The non-inverting inputs are on a pin with configurable
pull-up/pull-down/float, and the inverting input voltages can be
adjusted, along with selectable hysteresis from a couple low mV-range
values. And the outputs can be configured open-drain or push-pull, and
out to a pin, also with configurable pull-up/pull-down/float.
Unfortunately it's not possible to configure them as inverting so
easily so if this task can be done with just passives and
non-inverting comps with those constraints and put those comps to a
purpose, that'd be awesome, any suggestions appreciated!
can't make the comparator input a logic output once in awhile).
...
3state (cap discharged)
output HIGH (100 us)
3state (cap discharges, LED ON)
3state (cap reaches threshold, LED OFF)
3state (cap discharges)
...
Cheers
Phil Hobbs
On 11/28/2023 3:05 PM, Phil Hobbs wrote:
On 2023-11-28 14:46, bitrex wrote:
So I have a SPLC that's infrequently outputting ~ 100uS positive-goingOne approach would be to hang a parallel RC on one of the comparator's +
pulses on a few pins, and on two of the lines I'd like to stretch that
pulse out to blink an LED for the user to confirm activity.
Here is my nice-to-have constraint, I have four comparators in the
device (GreenPAK) that aren't currently being used for anything.
The non-inverting inputs are on a pin with configurable
pull-up/pull-down/float, and the inverting input voltages can be
adjusted, along with selectable hysteresis from a couple low mV-range
values. And the outputs can be configured open-drain or push-pull, and
out to a pin, also with configurable pull-up/pull-down/float.
Unfortunately it's not possible to configure them as inverting so
easily so if this task can be done with just passives and
non-inverting comps with those constraints and put those comps to a
purpose, that'd be awesome, any suggestions appreciated!
input pin, drive the LED from its output to ground, and turn it on by
transiently pulling the input high (use a second tristate pin if you
can't make the comparator input a logic output once in awhile).
...
3state (cap discharged)
output HIGH (100 us)
3state (cap discharges, LED ON)
3state (cap reaches threshold, LED OFF)
3state (cap discharges)
...
Cheers
Phil Hobbs
Yeah, that's a neat idea! I hadn't thought of twiddling with the 3 state pins. Pins can be configured as analog IO or digital IO but not analog in/digital out, but I think I have some spare 3 state digital IO lines I
can abuse for that purpose.
There are two-comparator solutions that I've seen that first use an open drain output to discharge a series RC but this saves some parts
On 11/28/2023 5:01 PM, Phil Hobbs wrote:
bitrex <user@example.net> wrote:
On 11/28/2023 3:05 PM, Phil Hobbs wrote:
On 2023-11-28 14:46, bitrex wrote:
So I have a SPLC that's infrequently outputting ~ 100uS positive-going >>>>> pulses on a few pins, and on two of the lines I'd like to stretch that >>>>> pulse out to blink an LED for the user to confirm activity.One approach would be to hang a parallel RC on one of the
Here is my nice-to-have constraint, I have four comparators in the
device (GreenPAK) that aren't currently being used for anything.
The non-inverting inputs are on a pin with configurable
pull-up/pull-down/float, and the inverting input voltages can be
adjusted, along with selectable hysteresis from a couple low mV-range >>>>> values. And the outputs can be configured open-drain or push-pull, and >>>>> out to a pin, also with configurable pull-up/pull-down/float.
Unfortunately it's not possible to configure them as inverting so
easily so if this task can be done with just passives and
non-inverting comps with those constraints and put those comps to a
purpose, that'd be awesome, any suggestions appreciated!
comparator's +
input pin, drive the LED from its output to ground, and turn it on by
transiently pulling the input high (use a second tristate pin if you
can't make the comparator input a logic output once in awhile).
...
3state (cap discharged)
output HIGH (100 us)
3state (cap discharges, LED ON)
3state (cap reaches threshold, LED OFF)
3state (cap discharges)
...
Cheers
Phil Hobbs
Yeah, that's a neat idea! I hadn't thought of twiddling with the 3 state >>> pins. Pins can be configured as analog IO or digital IO but not analog
in/digital out, but I think I have some spare 3 state digital IO lines I >>> can abuse for that purpose.
There are two-comparator solutions that I've seen that first use an open >>> drain output to discharge a series RC but this saves some parts
You can do a bunch of semi-analog things like that by bodging the pull
up/down and 3state controls.
It’s sort of like the uC equivalent of the 555. ;)
Cheers
Phil Hobbs
A hack I've used a couple times to squeeze a bit more logic out of these (they don't have much, and AFAIK there's no VHDL-like compiler for most
of the chips so you're sometimes on your own on the minimization front),
is use the 3 state control
bitrex <user@example.net> wrote:
On 11/28/2023 3:05 PM, Phil Hobbs wrote:
On 2023-11-28 14:46, bitrex wrote:
So I have a SPLC that's infrequently outputting ~ 100uS positive-going >>>> pulses on a few pins, and on two of the lines I'd like to stretch that >>>> pulse out to blink an LED for the user to confirm activity.One approach would be to hang a parallel RC on one of the comparator's + >>> input pin, drive the LED from its output to ground, and turn it on by
Here is my nice-to-have constraint, I have four comparators in the
device (GreenPAK) that aren't currently being used for anything.
The non-inverting inputs are on a pin with configurable
pull-up/pull-down/float, and the inverting input voltages can be
adjusted, along with selectable hysteresis from a couple low mV-range
values. And the outputs can be configured open-drain or push-pull, and >>>> out to a pin, also with configurable pull-up/pull-down/float.
Unfortunately it's not possible to configure them as inverting so
easily so if this task can be done with just passives and
non-inverting comps with those constraints and put those comps to a
purpose, that'd be awesome, any suggestions appreciated!
transiently pulling the input high (use a second tristate pin if you
can't make the comparator input a logic output once in awhile).
...
3state (cap discharged)
output HIGH (100 us)
3state (cap discharges, LED ON)
3state (cap reaches threshold, LED OFF)
3state (cap discharges)
...
Cheers
Phil Hobbs
Yeah, that's a neat idea! I hadn't thought of twiddling with the 3 state
pins. Pins can be configured as analog IO or digital IO but not analog
in/digital out, but I think I have some spare 3 state digital IO lines I
can abuse for that purpose.
There are two-comparator solutions that I've seen that first use an open
drain output to discharge a series RC but this saves some parts
You can do a bunch of semi-analog things like that by bodging the pull up/down and 3state controls.
It’s sort of like the uC equivalent of the 555. ;)
Cheers
Phil Hobbs
So I have a SPLC that's infrequently outputting ~ 100uS positive-going pulses on a few pins, and on two of the lines I'd like to stretch that
pulse out to blink an LED for the user to confirm activity.
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