I love your ingenuity. Reading your post made my evening. Keep up the good work :-) .
On Thursday, July 24, 2014 8:03:34 AM UTC-5, Pavel Milanes Costa wrote: > > Hi, > > First Thanks to all for the replies, I - as always - learn a lot with > your answers. > > I'm on the super cheap project here, no just "cheap" for being cheap, > but as for no pieces !!! > > I'm in Cuba island, no ebay, no radioshack, etc... just a big junkbox >:-) > > I rescued a PIC16F630 from a auto alarm, it has 14 pins, 12 to use and > 11 to be outputs + 1 pin input only, I rescued a LCD from an old VCR for > the 7 seg display. > > I settled on the timer0_isr_interval for this time... > > I used the internal 4 Mhz clock of the pic, internal MCLR, and created a > routine for multiplexing the display using the tomer0_isr_interval... > > All working good... (at the display stage) if you are doing the math I > have 11 pins (7 segments + 4 common anodes for the digits) so the dot > was running from an independent and cheap 4069 inverters :-) > > The input only pin is for setting the time... > > I have two options for the clock, that's why I asked the question in the > first place... > > After experimenting and calibrating I choose the timer0_isr_interval > version, here is why... > > /(The pic has a 5.00 volts as per a LM317T in the power supply... so no > voltage variations to affect the clock)/ > > *rtc_timer1 option:* > > I have to user it on timer1, because timer0 has the timer0_isr_interval > for multiplexing the display. > > With this option I have only one point to calibrate OSCCAL, I made a > routine to modify it and load the adjust in the eeprom of the pic. > > Results of experimentations: > > The step of adjust are to wide apart, my best setting was > > OSCCAL = 20: delay of about 3 minutes in 24 hours > OSCCAL = 21: increase of about 5 minutes in 24 hours > > Not so good, reading the pic datasheet, I se that moving the VCC I can > tuner the INT_OSC.. but na... > > *timer0_isr_interval option:* > > It's there already for the 7 segment multiplexing... > > The adjust was incrementing/decrementing the ticks on the slot... the > previous routine for modify the OSCCAL was modified to tune the ticks > count on the particular slot on the isr_interval > > Results of experimentations: very good !!!! > > In theory with 1khz ticks I have to load the slot with 1000 for 1 > second, but with an adjust of 1301 I have under 5 seconds increase per > 24 hours... > > For the record, with 1300 I have a delay of about 30 seconds... > > So I stick to this variant... this is a good project for learning about > timer0_isr_interval and and rtc_* libraries... > > At the end I have the pic, the display, a bunch of resistors + > capacitors, a LM317 and a 4069 inverters, just that to make a neat and > homebrew clock... > > I then learn that WWVH? in 70Khz can reach Cuba on the nights, I'm > searching info to *try* to make a lib for decoding the WWVH... If I > succeed I will contribute it to jallib... > > Thanks to all. > > PS: I any want to peek in the code drop me an email... > > > El 22/07/14 17:24, Pavel Milanes Costa escribió: > > Hi to all... > > > > I'm building a 7 Segment desk clock as a hobby project, and I ran across > > two methods to get the 1 second increments... > > > > - timer0_isr_interval > > Setting a 1Khz rate and a slot with tick to make one second > > > > - rtc_isr_tmr0 > > A "more accurate solution" over time... > > > > There is any pros and cons about one method or the other? > > > > I read that rtc_isr_tmr0 is more accurate over time with jitter on the > > seconds count... but, > > > > This is realy true? any reason to use timer0_isr_interval over this? > > > > cheers > > > > Pavel. > > > On Thursday, July 24, 2014 8:03:34 AM UTC-5, Pavel Milanes Costa wrote: > > Hi, > > First Thanks to all for the replies, I - as always - learn a lot with > your answers. > > I'm on the super cheap project here, no just "cheap" for being cheap, > but as for no pieces !!! > > I'm in Cuba island, no ebay, no radioshack, etc... just a big junkbox >:-) > > I rescued a PIC16F630 from a auto alarm, it has 14 pins, 12 to use and > 11 to be outputs + 1 pin input only, I rescued a LCD from an old VCR for > the 7 seg display. > > I settled on the timer0_isr_interval for this time... > > I used the internal 4 Mhz clock of the pic, internal MCLR, and created a > routine for multiplexing the display using the tomer0_isr_interval... > > All working good... (at the display stage) if you are doing the math I > have 11 pins (7 segments + 4 common anodes for the digits) so the dot > was running from an independent and cheap 4069 inverters :-) > > The input only pin is for setting the time... > > I have two options for the clock, that's why I asked the question in the > first place... > > After experimenting and calibrating I choose the timer0_isr_interval > version, here is why... > > /(The pic has a 5.00 volts as per a LM317T in the power supply... so no > voltage variations to affect the clock)/ > > *rtc_timer1 option:* > > I have to user it on timer1, because timer0 has the timer0_isr_interval > for multiplexing the display. > > With this option I have only one point to calibrate OSCCAL, I made a > routine to modify it and load the adjust in the eeprom of the pic. > > Results of experimentations: > > The step of adjust are to wide apart, my best setting was > > OSCCAL = 20: delay of about 3 minutes in 24 hours > OSCCAL = 21: increase of about 5 minutes in 24 hours > > Not so good, reading the pic datasheet, I se that moving the VCC I can > tuner the INT_OSC.. but na... > > *timer0_isr_interval option:* > > It's there already for the 7 segment multiplexing... > > The adjust was incrementing/decrementing the ticks on the slot... the > previous routine for modify the OSCCAL was modified to tune the ticks > count on the particular slot on the isr_interval > > Results of experimentations: very good !!!! > > In theory with 1khz ticks I have to load the slot with 1000 for 1 > second, but with an adjust of 1301 I have under 5 seconds increase per > 24 hours... > > For the record, with 1300 I have a delay of about 30 seconds... > > So I stick to this variant... this is a good project for learning about > timer0_isr_interval and and rtc_* libraries... > > At the end I have the pic, the display, a bunch of resistors + > capacitors, a LM317 and a 4069 inverters, just that to make a neat and > homebrew clock... > > I then learn that WWVH? in 70Khz can reach Cuba on the nights, I'm > searching info to *try* to make a lib for decoding the WWVH... If I > succeed I will contribute it to jallib... > > Thanks to all. > > PS: I any want to peek in the code drop me an email... > > > El 22/07/14 17:24, Pavel Milanes Costa escribió: > > Hi to all... > > > > I'm building a 7 Segment desk clock as a hobby project, and I ran across > > two methods to get the 1 second increments... > > > > - timer0_isr_interval > > Setting a 1Khz rate and a slot with tick to make one second > > > > - rtc_isr_tmr0 > > A "more accurate solution" over time... > > > > There is any pros and cons about one method or the other? > > > > I read that rtc_isr_tmr0 is more accurate over time with jitter on the > > seconds count... but, > > > > This is realy true? any reason to use timer0_isr_interval over this? > > > > cheers > > > > Pavel. > > > -- You received this message because you are subscribed to the Google Groups "jallib" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. 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