Picaxe 20x2

Mycroft2152

Senior Member
The specs on the PICAXE 20X2 have now been released, the chip will be available shortly.

A quick browse through the updated manuals show some very interesting and exciting new built in functions for the 20X2.

64 mHz operation without a crystal

A built in comparator

A background timer

A SR Latch (set/reset)

Interfacing with the UNI/O one wire eeproms

Overall a very welcome surprise.
 

slurp

Senior Member
I think it's got the WOW! factor.

I think I'm going to need to re-design a few boards to fit an extra pin or two and make use of these features - there goes my favoured 18X....

The flexibility of I/O locations is excellent, it's got to make circuit design easier - heck, too much choice just as I was making up some new 18X boards :rolleyes:

regards,
colin

I'm wondering if ADCSETUP will be hackable with the special function registers...
 
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Wrenow

Senior Member
Methinks a VERY sophisticated radio control encoder system becomes pretty darned simple with 11 freakin' ADCs. (let's see now, 8 priomary channels, plus 3 proportional mixes...logical mixes,,,.) Pardon while I wipe the drool from my chin......


Cheers,

Wreno
 

jmumby

Senior Member
Wow, I mean wow. 1024 scratchpad thats 10x what I have now and the speed. Crikey these are gonna be ex$pensive!
 

jmumby

Senior Member
Well 28x1 are over £10 in New Zealand, but 20x2 does appear cheaper so I hope they will be more affordable!
 

Dippy

Moderator
They look fantastic value.
Being based on the PIC K series the have many benefits including the extra clock speed.
And amazingly at lower cost.

I can now appreciate the extra time it's taken to release them.
Keeping in mind I am not privvy to any firmware development I remember there were some funnies associated with the early batches of the K series. Even without the funnies there are some changes that have to be made as they are not internally identical.

And some of the (nothing-related-to-PICAXE) software I ported from 18Fxx to 18FxxK needed some twiddling to make them work.

When you get to be a Bigger Boy you will also have to read the Microchip 'Errata' Data Sheets too. Later batch Ks of the PIC I tend to use has a smaller Errata sheet so someone has adjusted the sand mix somewhere!

All in all this is a significant step. Well done Rev-Ed!!
 

hippy

Senior Member
A straight £3.50 conversion at current exchange rates indicates - USD 5.00, AUD 7.25, NZD 8.78 ( www.xe.com ).

What that works out to in reality is perhaps anyone's guess and this is just this instant's snapshot. Exchange rates seem to be all over the place recently and vary from day to day and more differently between any currency and another than they have in the past. This of course affects transportation costs and import duties, and works in all directions.
 

jmumby

Senior Member
Well if they clip the ticket like NZ there will be 100% markup so £3.50 x 2 £7.00 x 2.07 (31/03/09) = $14.49 so AU$14-AU$15.
 

manuka

Senior Member
Perhaps it's best to just relate to MicroZed's 18X (Aus$16) price- which Tech. Supplies sell at £3.70 excl. VAT. As they've the 20X2 listed at £2.99 excl. I'd say Aus$12 will be close to downunder retail.

FWIW exports ex. UK are of course exempt their 15% VAT, as are (modest) imports to Aus/NZ our 10-12½% GST.
 

SD2100

New Member
Thanks... I did the conversion and stuck a bit on top but that still looked cheap, so if it's close to Manuka's $12 that would be exellent.
 

kranenborg

Senior Member
64MHz or 32 Mhz max?

Hello,

First of all, I am not always the one that tries to spoil a party ... don't kill the messenger of the bad news ...

From the PIC18F14K22 datasheet on page 7 I get the following when the internal oscillator is used (and which is the case for the Picaxe-20X2):

"Used with the internal oscillator, the PLL gives users a complete selection of clock speeds, from 31 kHz to 32 MHz – all without using an external crystal or clock circuit.".

Furthermore, on page 20, the definition of the PLLEN bit of the OSCTUNE register states that the PLL can only be enabed at HFOSCINT = 8 MHz.
This would lead me to the conclusion that a maximum of 4 x 8 = 32 MHZ can be reached, not 64 MHz.

On the other hand, on page 1 in the "Flexible Oscillator Structure" section it is clearly stated that: "64 MHz performance available using PLL – no external components required"

What is the truth here (and we cannot test it yet since the chip is not yet available)?

/Jurjen
 

SilentScreamer

Senior Member
Hello,

First of all, I am not always the one that tries to spoil a party ... don't kill the messenger of the bad news ...

From the PIC18F14K22 datasheet on page 7 I get the following when the internal oscillator is used (and which is the case for the Picaxe-20X2):

"Used with the internal oscillator, the PLL gives users a complete selection of clock speeds, from 31 kHz to 32 MHz – all without using an external crystal or clock circuit.".

Furthermore, on page 20, the definition of the PLLEN bit of the OSCTUNE register states that the PLL can only be enabed at HFOSCINT = 8 MHz.
This would lead me to the conclusion that a maximum of 4 x 8 = 32 MHZ can be reached, not 64 MHz.

On the other hand, on page 1 in the "Flexible Oscillator Structure" section it is clearly stated that: "64 MHz performance available using PLL – no external components required"

What is the truth here (and we cannot test it yet since the chip is not yet available)?

/Jurjen
I imagine 64Mhz is possible. It is on all the rev-ed information and I doubt they didn't test it at 64Mhz at all (it'd be asking for problems if they did).
 

manuka

Senior Member
I plowed on thru' P.5 & it's "To our valued customers" to find P.22 mentions a LFINTOSC & HFINTOSC relating to the internal oscillator. The latter setting apparently gives the full 64 MHz.
 

kranenborg

Senior Member
Thanks Manuka, that probably settles it: Section 2.2 clearly states that 64MHZ is possible with the internal oscillator! No bad news, but the datasheet is not very consistent though.

Jurjen
 

Technical

Technical Support
Staff member
The PLL is software controlled, and can be enabled at 8 (=32) or 16 (=64) MHz.
So that gives 8 internal options + 2 more PLL 'turbo boosted' speeds.
Microchip new part datasheets are 90% recycled and sometimes mistakes are made in the preliminary releases for new parts.
 

MartinM57

Moderator
Is there any even approximate availability date that I've missed somewhere (and quantity availability)?

I might be wanting to design something for a several hundred off production run, in a reasonably short timeframe, but I can't use a component in a design that's not yet available....
 

SilentScreamer

Senior Member
Is there any even approximate availability date that I've missed somewhere (and quantity availability)?

I might be wanting to design something for a several hundred off production run, in a reasonably short timeframe, but I can't use a component in a design that's not yet available....
Microchip still have it as a future product.
 

MartinM57

Moderator
..and I note that 20x2 appears nowhere within Manual 2 (Basic Commands) :(

@SS - Mouser have the PIC on future delivery with about 150 available in Mid May
 

MartinM57

Moderator
Look at Manual 2, rev 6.8 dated 2/09?

The 20X2 chips are in there.

Dave E
Ah - I was looking at the manuals that came with v5.2.4 of the PE - unless installing v5.2.4 on top of a previous version doesn't update the manuals?

A small Google later, and I now have the latest versions, Ta...
 

nbw

Senior Member
It's a sad fact but my wife can get 3 books out from the UK to NZ cheaper than I can get 3 picaxe chips covering the same distance!

You'd think something pretty much as small / light as a christmas card wouldn't cost much to send... but it does.
 

slurp

Senior Member
You'd think something pretty much as small / light as a christmas card wouldn't cost much to send... but it does.
Clearly you haven't factored the weird and wonderful rules the Royalmail have been dreaming up for charging mechanisms.

Aside from weight, I assume that your Christmas Card will be less than 5mm think and not greater than 240x165mm in other dimensions... I'm guessing that your chips will have bumped up the scale on thickness alone!

We're at the point where we need to use the online price wizzard to work out what anything costs to post.... it's like looking for a low-cost airline seat, I'm sure if I find the right time and day I'll get it for 1/2 the price! ;)

regards,
Colin
 

boriz

Senior Member
"we need to use the online price wizzard to work out what anything costs to post"

And when you turn up at the post office, they give you a different estimate.
 

hippy

Senior Member
I cannot comment on specific pricings or particular comparisons but there are a number of factors which can affect things and the assumption of "bigger or heavier will be more expensive" does not necessarily hold true.

Thickness and size of package can cause a large difference so a small package with a chip inside can be much more expensive than a thin, larger package. Weight bands can be tightly grouped giving higher costs for small differences in weight.

Printed papers and books can attract a reduced postage rate so it can be cheaper to send a huge, extremely heavy book than smaller, lighter items.
 

manuka

Senior Member
Quite by chance, or because of Royal Mail strife, several recent (non PICAXE) ex UK packages to hand here in NZ have arrived with totally unfranked stamps. The temptation to cut them off & return for a 2nd UK-NZ trip is naturally strong.
 

MartinM57

Moderator
The latest UK stamps have an anti-peel mechanism on them - two areas that will remain attached to the envelope when you try to peel them off

And presumably Royal Mail will take a dim view of stamps that appear to have been cut off some previous envelope and sellotaped on!
 

slimplynth

Senior Member
I have a dream

Carrier pigeons are rubbish. Great White sharks on the other hand; Japanese scientists have already commandeered the nervous system of cockroaches...

"Ladies and Genltemen! I present to you the Picaxe Postal Shark!" <insert raputurous applause>

OK - we just need someone in the southern hemisphere to provide the sharks and I'll provide the components ;)

I know there'll be doubters to this concept.. "we'll need a method of loading and unloading I hear".. The plan is to pack the parts in a waterproofed container (Apparently a great white can consume at least a couple of hundred Kg of food in one sitting).. wrap the container(s) in meat.. shark eats meat & container(s).. swims under guidance to Oz.. where it's commanded to puke its guts based on a preprogrammed GPS position that tells the sharks brain to empty it's belly.

(We'll also need an animal neuroloist and possiby a vet)

It could work, we just need to not tell Green Peace and erase our own environmental consciences.

on reflection - it's been a slow week at work, day dreaming might not be the answer. sorry if you're still reading this.. sorry :)
 
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