Redundant Picaxe chips.

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eclectic

Moderator
I wonder how many “redundant” Picaxe chips are lying about unused,
after people have upgraded to newer versions?
I've just “found” 08, 14M, 18, 28X and 40X.

Perhaps members could suggest projects, serious or frivolous,
that could be made simply and cheaply.
Some of these may even have educational value.

Thinking five months ahead, as a couple of examples:

A 16 LED “chaser” with a 28X
A “mood” light, using R G B.

e
 
hippy

hippy

Ex-Staff (retired)
There have been few firmware upgrades which have made old PICAXE's redundant, many projects can use older chips as well as the newer versions. The biggest change was perhaps when the 18X 8.2 went to supporting 256 GOSUB's so 8.0/8.1 are sometimes less useful.

Perhaps the real question is why are people using newer versions when there are older versions they could be using ? Why buy a newer chip when the older work perfectly well ?
 
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Andrew Cowan

Senior Member
If I need 28 pin PICs, then I just use a 28X - I haven't bought any 28X1s yet, as I don't have a problem with 28Xs. I know that the 28X1s have more features, but, as Hippy says, why buy a newer chip when the older work perfectly well?

Andrew
 
E

eclectic

Moderator
@Hippy.
and Andrew in the future?

I agree totally with the logic of your statements.
If it's for a specific task, then buy the tool that does the job.

However, from a pure hobby / pastime viewpoint,
be it photography / cars / Hi-Fi or whatever else,
then it's the "best toy in the shop" principle.
And indeed, the spending of the money.

I know many, mainly male, who fit that profile perfectly.

e.

(Who probably has more money than sense. And little money!)
 
W

westaust55

Moderator
e,

There is the old adage:

You can tell the men from the boys


By the price of their toys.



Westaust55
============
$10,000 worth of model railway :)
 
P

papaof2

Senior Member
Atlanta has the "Big Boys' Toys" store, which is a used car dealer specializing in sports and muscle cars.

John
 
hippy

hippy

Ex-Staff (retired)
In the future ... I'll probably keep using whatever I have to hand and can do the job or buy those I need for a project.

I'll admit that I have a lot of unused 08's, 18's and early 18X in drawers but that's more because I bought in bulk and don't build enough projects. 08's and 18's aren't very useful for ADC, those without READADC10 not always up to requirements. It is 'right tool for the job', I just haven't got any jobs for them :)

The biggest issue with using old Firmware is trying to remember what bugs there were. I've wasted time on that when a program should work but didn't and it is a nuisance.

I think it's a bit like upgrading PC's, what to do with the old one ? Does it have any use, what about the 10 year old 486 ?
 
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womai

Senior Member
Actually sometimes older chips have advantages, too. I have a design that uses the 28X. I tried to upgrade it to 28X1, only to find out that the 28X1 isn't as forgiving when running it at high speed and low voltage (16 MHz at 3.3V in my case), while the 28X has no problems with that. (a glance at the respective Microchip datasheets indeed shows that the 28X1 wants a higher minimum voltage at that frequency; even the 28X is somewhat beyond spec but not too far). Too bad since my design could really need the additional 28X1 features (hardware serial for example); so I am now in the process of converting it over to a bare Microchip 16F873A programmed in C :(

Wolfgang
 
E

eclectic

Moderator
@WestAus and John

If I could be bothered to have a signature line,
it would be this......

Old boys have their playthings as well as young ones.
The difference is only in the price.

Benjamin Franklin 1752.

(Still pinned up on my Darkroom door, after 20 years.)

But seriously, has anyone got any projects/toys to make from
"waiting for a home" Picaxes?

e.
 
kranenborg

kranenborg

Senior Member
I simply cannot imagine the day for an 18X (and also 08M and 14M) to become redundant ... (which reminds me to order a few new 18Xes)

/Jurjen
 
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inglewoodpete

Senior Member
The 08M and 14M are fantastic chips, for sure, but I look forward to versions with 512 bytes (or more) of program space.

8 and 14 pin PICAXEs are far easier to design PCBs around, but they can be very limiting for complex programming or handling LCDs with lots of strings.

Also, less space used for music (that is rarely used outside the classroom) and perhaps firmware ShiftOut and ShiftIn commands. But then, the classroom is the major market for these chips.

I look forward to future upgrades.
 
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manuka

Senior Member
This musing reminds me of a imaginative end use a tray of redundant 7404 style TTL logic ICs was once put to our lab- as "super grip" thumb tacks on a noticeboard !
 
D

Dippy

Moderator
"it is frustrating running out of room on an 08M, and having to redesign the circuit to use an 18X."

- very true, and when you have dabbled a bit more you'll get a feel for the right Horse for the Course before you start.
Then you'll start calling it Project Planning :)
 
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marcos.placona

Senior Member
I always like to start small, and then move to bigger chips. Normally I have a 08M wired on the breadboard by default.

I do some tests, and then move to a cool and well done schematic. I rarely have this kind of memory hassle as I plan it well before actually starting to do the stuff.
 
D

Dippy

Moderator
What's "a cool and well done schematic" ?
Is that the same as "good schematic" or "an awesome schematic" ?
 
M

marcos.placona

Senior Member
Dippy said:
What's "a cool and well done schematic" ?
Is that the same as "good schematic" or "an awesome schematic" ?
Click to expand...
I'd say an awesome schematic. The first one is just a sketch, and sometimes I even draw it by hand.

Then I see if it works, and if my idea is not too crazy (most of the time it is :D).

From that point I stop being lazy and do something on eagle.
 
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Andrew Cowan

Senior Member
Planning?!? You weirdos. That's like saying that you mark where the holes should be before you start drilling - a waste of time :D

Andrew
 
hippy

hippy

Ex-Staff (retired)
My approach for software has been to start large ( usually an 18X ) so there are no constraints I'm likely to run up against and then move down when the software is nearly finished and I/O requirements determined. Having far more program space than needed makes it far easier to add SERTXD debugging than when the program you're trying to debug has filled the chip.

Project Planning, as Dippy suggests, sets the 'ball park requirements' so if you need 10-bit ADC don't start with something which doesn't have that, if it's going to be complicated software or need a lot of on-chip Eeprom don't start with an 08 or 18. It's usually harder to move upwards than it is to go downwards in my experience. Not having an extra I/O line when it becomes obvious one's needed brings a project to a grinding halt. If you're on a bigger PICAXE to start with, it simply reduces the downgrade options, or gets added to the list of re-design needed to move downwards.

If starting small, you often end up designing to fit what you have and throwing out options which you might otherwise like to include. That's okay if you really must use that PICAXE, but if you have the choice it's usually better to have a project which is as good as it can be and use the best PICAXE which does the job. Skimping on a few pieces of loose change can often be a false economy.
 
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