This is software vs hardware. An extra chip for each servo is easy to design & build, but each application will need that extra chip. Software is - in this case - more complex, but once it is addressed it does not require any attention any more. This is why i'd love to have a library that can be easy applied, has no (or low) jitter and does not impose a high load on the cpu. But I am repeating myself over and over and better shut up ;)
Joep 2010/2/4 vasile surducan <[email protected]>: > Hi Joep, Matt, > I've asked because I'm wandering if it's not easiest using one 10F202 or > so for every servo without any ISR source except the servo and > communication. You know better the servo purpose, but I guess even from the > hardware perspective this will be a nice option. PIC board could fit > directly into the servo. > > On 2/3/10, Joep Suijs <[email protected]> wrote: >> >> yes. *if* other ISR sources occure, there will be. The chance of >> jitter (how often a pulse is lengthed by an other isr) depends on the >> rate and processing time of each isr. >> >> If you use serial comms without isr (or adapt i2c slave to work >> without interrupts) the signal can be perfect. >> I have a pob-servo, which has a parallel comms bus and supports 20 >> servos perfectly stable with one pic. So it can be done... >> >> IMHO the design of the library should minimise the jitter on it's own >> (preferable none if there are no other interrupts) and impose as >> little as possible restrictions on your application to maintain tlis >> minimal level in more complex configurations. >> As said before, it can be done. But if this was easy, I'd made such a >> library years ago ;) >> >> Joep >> >> >> >> 2010/2/3 vasile surducan <[email protected]>: >> > >> > >> > On 1/31/10, Joep Suijs <[email protected]> wrote: >> >> >> >> 2010/1/31 Joep Suijs <[email protected]>: >> >> > >> >> > IMO it would be better to reporgram a (16 bit) timer and only >> >> > generate >> >> > an interrupt when there is an action, >> >> >> >> Or maybe use timer2 (8 bit), so timer1 remains available for ccp. >> > >> > >> > One question: if other random events will be treated in the ISR >> > (asuming >> > the microcontroler is not only a servo driver connected as an I2C slave) >> > will not allways occure a variable jitter, no mater of timer resolution? >> > >> > Vasile >> > >> > >> > -- >> > You received this message because you are subscribed to the Google >> > Groups >> > "jallib" group. >> > To post to this group, send email to [email protected]. >> > To unsubscribe from this group, send email to >> > [email protected]. >> > For more options, visit this group at >> > http://groups.google.com/group/jallib?hl=en. >> > >> >> -- >> You received this message because you are subscribed to the Google Groups >> "jallib" group. >> To post to this group, send email to [email protected]. >> To unsubscribe from this group, send email to >> [email protected]. >> For more options, visit this group at >> http://groups.google.com/group/jallib?hl=en. >> > > -- > You received this message because you are subscribed to the Google Groups > "jallib" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/jallib?hl=en. > -- You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/jallib?hl=en.
