timothy48342
- Nov 28, 2011
- 218
- Joined
- Nov 28, 2011
- Messages
- 218
Small question first.
While reading up on programming PICs, I keep coming across this terminology.
VIL. (That's a big V and an IL subscript.)
As in:
pdf link
Also VIHH. (Big V, and subscript IHH) as in:
(The "Programming Specifications" they refer to is that first link.)
I also saw a reference to current with similar subscripts, but can't find the reference now. I was something like "...with the ability to draw IIL current..." Again, the first "I" is big and the remaining "IL" is a subscript and it was in the same context as the first ones. VIL and VIHH.
I guess the reason I need to know is when I'm ready to supply the Vpp pin with 12.5 to 13.5 V for programming, is that going to be a logical level that can have a reasonably high impeadance or is the chip going to be drawing significant current from that lead to the extent that I need to make sure there is some amount of current available? Like I-il or I-ihh current.
That's one question... just terminology. And maybe it doesn't matter. I'm buying $2 chips and I'm buying 10 of them, so I could just juice the first one and see what happens, I suppose.
Next question, "Am I insane??"
My strategy for learning about microcontrollers in going to be buy a cheap and small chip with limited features that doesn't have nearly the community surrounding it that other microcontrollers have.
Then on top of that, build my own programer as my introduction to the field and never ever buy a programmer or development board. (Going against advice that I have seen other newbies receive. And I'll build one for the serial port rather than the USB, so it really amounts to some wires and 1 or 2 resistors. ...I think... and maybe 13V's worth of batteries.) Of course, I'll have to come up with the code to drive the serial port manually, and I havn't looked into that, but that's just code and Windoze API. I think I can figure that out.
On top of that, I intend to light my first LED in assembler mostly because I want to learn Assembler (again). I'll download the Microchip compiler later after I learn how things work on a low-level and when I need it for larger programs.
So... Many of you probably have a grasp of the electronics skill level that I am at from my postings and that is my weak point, I know. I know some stuff! I don't know some other stuff!
Strong points: I can read a datasheet. (Ok, I can read 30% of a datasheet.) I'm pretty good at internet research. Google is my friend. Google is my best friend. (I think Google and I might already be married, I'll have to check the local laws as see.)
So, here is some more info about me.
My programming language of choice has been C++ for many years now. Programmed in Applesoft Basic many years ago. Programmed in Assembler at that same time, but not since. The 80-x86 infrastructure was to different to be convenient and C was so easy in comparison, that when C became available and the Apple 2 was fading, I made the switch to C and didn't bother with Assembler any more. I think I can re-learn Assem since the instruction set is so small and the architecture seems straightforward. (so far)
I am definitely going with the PIC series to start out and maybe just stick with that forever. (It's hard to say why now. I like that they continue to produce chips that have less features for VERY reasonable prices. I get the feeling that the other uC manufacturers are pushing the newest greatest thing always to get more money. And a few of you on here seem to swear by the PIC and that means something, too. I think I am hoping it fits my personality.)
But, I'm skipping the ready made development platforms and I believe I can skip buying a programmer or relying on bootstrapped chips. (I would end up having to reprogram a bootstrapped chip anyway when I inevitably do something wrong and wipe the bootstrap.)
So am I insane?
Am I biting off more than any normal person could chew?
Any caveats for me?
Has anyone else out there gone this route?
--timothy
(I've been planning on posting a "what should be my first microcontroller" thread, but I've read many, so this here is instead of that.) (And I'm gong to bed, then work, so it might be 24 hours or so before I wade through the responses.)
While reading up on programming PICs, I keep coming across this terminology.
VIL. (That's a big V and an IL subscript.)
As in:
That's from programming specification for the PIC10F200(and PIC10F2xx series) Page 3, section 3.1The sequence that enters the device into the Programming/Verify mode places all other logic into the Reset state (the MCLR pin was initially at VIL)
pdf link
Also VIHH. (Big V, and subscript IHH) as in:
From the PICF2xx datasheet. Page 50, section 9.12 pdf linkThe devices are placed into a Program/Verify mode by
holding the GP1 and GP0 pins low while raising the
MCLR (VPP) pin from VIL to VIHH (see programming
specification).
(The "Programming Specifications" they refer to is that first link.)
I also saw a reference to current with similar subscripts, but can't find the reference now. I was something like "...with the ability to draw IIL current..." Again, the first "I" is big and the remaining "IL" is a subscript and it was in the same context as the first ones. VIL and VIHH.
I guess the reason I need to know is when I'm ready to supply the Vpp pin with 12.5 to 13.5 V for programming, is that going to be a logical level that can have a reasonably high impeadance or is the chip going to be drawing significant current from that lead to the extent that I need to make sure there is some amount of current available? Like I-il or I-ihh current.
That's one question... just terminology. And maybe it doesn't matter. I'm buying $2 chips and I'm buying 10 of them, so I could just juice the first one and see what happens, I suppose.
Next question, "Am I insane??"
My strategy for learning about microcontrollers in going to be buy a cheap and small chip with limited features that doesn't have nearly the community surrounding it that other microcontrollers have.
Then on top of that, build my own programer as my introduction to the field and never ever buy a programmer or development board. (Going against advice that I have seen other newbies receive. And I'll build one for the serial port rather than the USB, so it really amounts to some wires and 1 or 2 resistors. ...I think... and maybe 13V's worth of batteries.) Of course, I'll have to come up with the code to drive the serial port manually, and I havn't looked into that, but that's just code and Windoze API. I think I can figure that out.
On top of that, I intend to light my first LED in assembler mostly because I want to learn Assembler (again). I'll download the Microchip compiler later after I learn how things work on a low-level and when I need it for larger programs.
So... Many of you probably have a grasp of the electronics skill level that I am at from my postings and that is my weak point, I know. I know some stuff! I don't know some other stuff!
Strong points: I can read a datasheet. (Ok, I can read 30% of a datasheet.) I'm pretty good at internet research. Google is my friend. Google is my best friend. (I think Google and I might already be married, I'll have to check the local laws as see.)
So, here is some more info about me.
My programming language of choice has been C++ for many years now. Programmed in Applesoft Basic many years ago. Programmed in Assembler at that same time, but not since. The 80-x86 infrastructure was to different to be convenient and C was so easy in comparison, that when C became available and the Apple 2 was fading, I made the switch to C and didn't bother with Assembler any more. I think I can re-learn Assem since the instruction set is so small and the architecture seems straightforward. (so far)
I am definitely going with the PIC series to start out and maybe just stick with that forever. (It's hard to say why now. I like that they continue to produce chips that have less features for VERY reasonable prices. I get the feeling that the other uC manufacturers are pushing the newest greatest thing always to get more money. And a few of you on here seem to swear by the PIC and that means something, too. I think I am hoping it fits my personality.)
But, I'm skipping the ready made development platforms and I believe I can skip buying a programmer or relying on bootstrapped chips. (I would end up having to reprogram a bootstrapped chip anyway when I inevitably do something wrong and wipe the bootstrap.)
So am I insane?
Am I biting off more than any normal person could chew?
Any caveats for me?
Has anyone else out there gone this route?
--timothy
(I've been planning on posting a "what should be my first microcontroller" thread, but I've read many, so this here is instead of that.) (And I'm gong to bed, then work, so it might be 24 hours or so before I wade through the responses.)