Thank you, I'll think more on this and create a test environment. Thank you for your guidance. Richard
On Fri, 1 May 2020, 15:36 Paul Andrews, <[email protected]> wrote: > You run them in parallel. In this scenario the faders don’t control the > digits, your loop does that. It just reads the on/off state of the faders > and figures out if that means a digit is on or off. Then it increments the > fader and figures out if it also needs to adjust how long the ‘on’ period > is for each one. Then loops again. > > On May 1, 2020, at 9:45 AM, Richard Scales <[email protected]> wrote: > > > Thank you very much for that, I'll keep reading it until I fully > understand (could be some time). Are these three faders running in parallel > or in series? > I think I can see how this might work if they are in parallel. Ie, > assuming 100 ticks per cycle, for each tick, check the status of each > fader, set and light the digits accordingly. > Am I close? In this scheme then, each tick must have to digits switched on > for a given time? > Am I still close or have I gone completely off piste? > Richard > > > On Fri, 1 May 2020, 13:48 Paul Andrews, <[email protected]> wrote: > >> I do all the fading in software. Imagine you are running three faders. >> One for overall brightness, one for fading in and one for fading out. When >> you’re figuring out if a digit is one you say: >> >> 1. For static digits, if the brightness fader is on, then that digit is >> on, otherwise it is off. >> 2. For the digit fading in, if the brightness fader is on and the fade-in >> fader is on then the. The digit is on, otherwise it is off. >> 3. For the digit fading out, if the brightness fader is on and the >> fade-out fader is on then the digit is on, otherwise it is off. >> 4. Increment the brightness fader. >> 5. Adjust the fade-in fader so it is a bit brighter. >> 6. Adjust the fade out fader so it is a bit dimmer. >> >> A ‘fader’ just needs to keep track of whether it is on or off. Like, for >> so many increments it is on, for a different number of increments it is >> off. It is easy to say that there are, for example, 100 increments (or >> ticks) before the cycle repeats. Then for 25% brightness you say it is on >> for 25 ticks and off for 75, then you start at the beginning again. This is >> basically how PWM works, so will effectively be PWMing the tubes yourself. >> >> The HV chip series are easily fast enough for you to do this directly >> from the microprocessor. >> >> On Thursday, April 30, 2020 at 11:56:06 PM UTC-4, Richard Scales wrote: >>> >>> Hello everyone, >>> >>> I am contemplating having a go at implementing some form of digit cross >>> fade effect of which I have zero experience, knowledge or understanding and >>> I am hoping that someone could point me in the right direction. >>> >>> I can see that there are established designs using HV5622 drivers which >>> are capable of cross fading digits that change and I'd like to implement >>> this myself. >>> >>> I already use the blanking signal via a PWM signal to perform overall >>> fading of the display (all tubes) though the trick must be maintaining full >>> brightness for the digits that stay static whilst varying the brightness of >>> the incoming and outgoing changing digits. >>> >>> If this assumption is correct then I'm also going to assume that, even >>> for the digits that remain static - they cannot be on all the time and >>> there must be some 'off' time during which the changing digits can be >>> faded. >>> >>> This all makes use of the persistence of vision thing that makes us >>> think that the display is static. >>> >>> If I'm still on the right track then I am guessing that there will be a >>> sufficient 'off' time for the static digits to allow the fading digits >>> (incoming and outgoing) to be presented at varying degrees of 'brightness'. >>> >>> In a very rough pseudo code kind of thing: >>> >>> >>> :start of transition >>> Set shift register for static digits, turn all digits on, wait long >>> enough for the 'full display' effect', turn all digits off >>> Set Shift register for outgoing digits only, turn on, wait long enough >>> though reduce this period during the course of the transition, turn all >>> digits off. >>> Set Shift register for the incoming digits only, turn on, wait long >>> enough for the digits to start appearing and increase this period during >>> the course of the transition, turn all digits off >>> Loop back to start until transition is complete >>> >>> Am I anywhere near close with this? >>> >>> Is there any published method? >>> >>> I have yet to point my scope at a working clock to investigate this >>> further - I currently have an inherent reluctance to do this following a >>> recent episode of clumsy probing resulting in the premature expiration of >>> the device that I was investigating :-( >>> >>> It's really just the concept that I would like to fully grasp, I find >>> that I can stare at sample code segments all day long and not make any >>> meaningful progress, though code segments are most welcome. >>> >>> All pointers gleefully received. >>> >>> Richard >>> >>> -- >> You received this message because you are subscribed to a topic in the >> Google Groups "neonixie-l" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/neonixie-l/UWcm5_T2868/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> [email protected]. >> To view this discussion on the web, visit >> https://groups.google.com/d/msgid/neonixie-l/2d0e8f3d-cb30-4dd7-b416-95f652ec956e%40googlegroups.com >> <https://groups.google.com/d/msgid/neonixie-l/2d0e8f3d-cb30-4dd7-b416-95f652ec956e%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- > You received this message because you are subscribed to a topic in the > Google Groups "neonixie-l" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/neonixie-l/UWcm5_T2868/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/CA%2B9r3s9%2BwtLp4U1LB9JqQfGHHUhLqfmv_3qH0z6L-YZDC2cx-w%40mail.gmail.com > <https://groups.google.com/d/msgid/neonixie-l/CA%2B9r3s9%2BwtLp4U1LB9JqQfGHHUhLqfmv_3qH0z6L-YZDC2cx-w%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > -- > You received this message because you are subscribed to a topic in the > Google Groups "neonixie-l" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/neonixie-l/UWcm5_T2868/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/0E824E10-ED0A-44F6-AD49-0602293D0C8F%40gmail.com > <https://groups.google.com/d/msgid/neonixie-l/0E824E10-ED0A-44F6-AD49-0602293D0C8F%40gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. 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