STAMP sized picaxe boards..?

[Craftybytes]

Any development towards "STAMP" sized modules for Picaxe chips similar to the "Arduino" style (see here: http://www.arduino.cc/en/Main/ArduinoBoardMini ) - using surface mount components..?

Would definitely ease the use of smd Picaxe chips and also allow for 'smaller' packaging of usefull and viable Picaxe based circuits..!!

I was toying with designing a small 40 pin IC socket sized datalogger type board - using the smd 28X1 chip running at 16Mhz with a DS1307 RTC smd chip and a 24LC256B smd I2C memory chip - any comments as to whether this would be usefull within the wider "PICAXE" community..?

TIA.

crafty
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[tarzan]

My wish list for such a PCB:

40X1 / 40X2
5V & 3.3V
400 KHz bus speed on all i2c
16 MHz X1 - 10MHz X2
24LC1025 addressable with solder blob
DS1337 RTC

I’m sure this list will grow.

 

[atarian]

i think it's a great idea but i think it would be better to use the PIC versions written in C as it would be faster and it would also be more powerfull

 

[Craftybytes]

Whoa..hang on peoples..

@tarzan -
I don't think one can squeeze all the relevant i/o pins of a 40X1/X2 chip plus any other i/o pins from the other chips into the quoted 40 pin IC socket format WITHOUT missing some of the more important ones in the process..!!

As it is - my preliminary outline of using the 28X1/X2 smd chips plus the i/o from the RTC and memory chips I was looking at in my first post will have i/o (plus power pins) amounting to close on the full 40 pins on a 40 pin IC socket format - and with smd components on a PCB probably no bigger than 1.2" (W) x 2.4" (L) - getting in a smd 28X1 chip plus the others with smd xtal and a few chip resistors & caps - not much room left..

@atarian -
Well most probably - BUT my aim was for a PICAXE based version - don't need to change any software ( or learn new programming language) - all 'Picaxe-BASIC' progs for what I'm trying to achieve..

Any futher comments appreciated..

crafty.
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[moxhamj]

A great idea. There is nothing stopping anyone buying SMD picaxe chips and building their own boards. There are a few people here who are experts at reflow soldering which is ideally suited to SMD.

The "wish list" can always be bigger! Why not add a max232 and radio?

I started with a picaxe project that was supposed to be just one chip and now the board is 6"x4". It is all the peripheral stuff that takes up the space - the power connector, the D9 plugs, the relays etc. So it is hard to design a small "all purpose" board.

But certainly special purpose boards can be that small or even smaller than dip40 if you put components on both sides.

 

[Craftybytes]

@Dr_Ac -

Always wondered how putting smd components on "both" sides of the PCB was actually done..?

Would certainly allow for more components to be loaded in the same design footprint..

crafty.
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[moxhamj]

There are hot air devices for precise heating. You can even solder SMDs by hand if you have a steady hand and go easy on the coffee for a day or so.

 

[westaust55]

Ths DS1307 is a slow i2c bus device.

Tarzan has suggested the DS1337 which is a fast i2c device and has 2 alarms from memory and is a larger chip (16pin?) in terms of pins. BCJKiwi has used the DS1337 as well. NO battery abckup or onboard RAM.

I have gone the way of the DS1338 which is fast i2c compatible, 100% compatible with the DS1307 in terms of features, back-up battery and onboard battery supported RAM but is in the SOIC8 (8-pin) surfaced mounted format.

It is horses for courses at the end of the day in terms of what people want but the DS1338 it is another option.

 

[Dippy]

I'm sure it would be a piece of cake to stampify a PICAXE onto a DILx0.6" format. On-board reg and download. Make it a swap-out for BS2?? Same size and better functions. Could then be used in some Stamp project boards.
I did an SM design a while back with a 28X, never finished it but the components fitted. Even tried an extended board and got an RTC on.
I can't see any problems other than justifying the cost, and I reckon that could easily be justified.

 

[Craftybytes]

Yep - been sitting on the 'thunderbox' for a little (.he.he..the light bulb in my brainspace goes on occassionally during these sessions - generally it be just "blank" ..he..he..) - thought of a hopefully simple way to ( as Dippy puts it ) 'Stampify' a PICAXE onto a DILx0.6" format - and yes with on-board reg and download socket - keeping quiet for the moment till it can pass "proof-of-concept" stages..!!

Even had a 'flash' on possible expansion "daughter" boards that this 'stampified' PICAXE board could plug into..

Anyway - if there be REAL interest in this packaging format for smd Picaxe chips then I'll see if I can do a layout for a suitable PCB as a starter..!!

Comments most welcome..

crafty.
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[stocky]

There are hot air devices for precise heating. You can even solder SMDs by hand if you have a steady hand and go easy on the coffee for a day or so.

I get the shakes WITHOUT the coffee - coffee keeps them away - is that bad Doc? LOL

 

[Dippy]

Thanks for the 'over-share' crafty.
I can't find my 28X version.
But this was an 18X version with a 24Lxx EEPROM. Includes regulator and reverse protection diode.
I made a through hole version for testing, but never made smd. I just did it to see if it would fit onto 28x0.6 DIL/DIP so haven't tidified it. So its simply a post autorouter proof of size.
I'm really surprised a Stamp clone hasn't been made. It seems an obvious leap to move into a market. Hey, I know nothing.

 

[Craftybytes]

'over-share' - he..he..

Thanks for the image Dippy - will give me some pointers when I start my layout efforts..

Had originally looked at the 18X as the main processor for my project - but ran out of i/o pins for what I was trying to do - so upped to the 28X1 - subsequently my project circuit finishes with 4 x 'output' pins spare for "other" uses..

For my project I'll probably use normal DIP packages - but just thought that there might be somebody out in the PICAXE world who'd like to have available "smd" versions of picaxe based PCB's already loaded ( similar to the Arduino types ) for their projects - thus my first post..!!

Your comments much appreciated..

crafty.
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[hippy]

@ Craftybytes : Sounds good so if you need it I'd suggest going for it. I'm sure developing it would be useful and rewarding even if it never turned into a physical product.

How useful it would be to anyone else really depends on what you come up with, how it appeals to others, and of course cost. If I were considering using Arduino I'd probably choose that stamp-style DIP carrier you linked to. Would I use an SMD PICAXE on a carrier ? Harder to say. If I were into datalogging I would perhaps be more inclined to.

I'd recommend coming up with a design and pinout and then asking what people think of it and consider what comments they come back with. For an SMD micro it's a case of being the only option to make that micro usable for the hobbyist so it has an implicit rationale, for a PICAXE it's more providing common facilities in a small package; download interface, crystal, I2C EEprom, RTC. People will however desire different things.

 

[Dippy]

Well, if its a one off own-project thing then you can do what you want.

For anything commercial it would be obvious to duplicate pinouts of already existing products, whether it be Stamp 24 pin or the 40 pin. But then you've got possible I/O issues (I think ALL Stamp pins are configurable as In/Out aren't they?). On the other hand, to be able to swap out a £30 BS2 for a £15 Stampaxe may be quite appealing.

I wouldn't ask opinions, waste of time. Define a pinout. Did Parallax ask you? No. They just worked out a logical and easy pinout scheme.

Even in that simple 'non-Stamp' example I showed, you can squeeze an 18X + reg + enh.download + EEprom. I had considered an RTC but would require extra pins for the BB.
If you went for a unique pinout you could incorporate them just fine.

It was merely a CAD 'exercise' which would have relieved the pain that some people have with a 2 or 3 component download circuit and a 3 component regulator.

Personally, I reckon that unless you can get some big boy to take it off your hands you'll be wasting time/money having some made. i.e. don't give up the day job. (Unless its for your own projects of course).

I would have imagined that the DILx0.6 format would have crossed Rev-Ed's mind too...?

 

[Mycroft2152]

.
I'm really surprised a Stamp clone hasn't been made. It seems an obvious leap to move into a market. Hey, I know nothing.

Dippy,

It may be obvious but, manufacturing a stamp sized PICAXE board will bring the price up to the me too regions. There has to be a large enough market to justify it.

I'm not sure there is enough volume to justify a doubling or tripling the price.

I thnk the closest you will come for a reasonable cost is somethng like the Boarduino.

Myc

 

[hippy]

I wouldn't ask opinions, waste of time. Define a pinout. Did Parallax ask you? No. They just worked out a logical and easy pinout scheme.

Unless one finds that the target market demands something particular and rejects the offering if it doesn't fit

First to market gets to set the pinout ( for good or bad ), everyone else has to play by those definitions. It would on the face of it be rather silly to design a PICAXE development board with a 3.5mm download socket which had a different pinout to the download socket used by Rev-Ed.

If Microchip produced a 1GHz, 256KB Flash 8-pin PICmicro for $2, pin compatible with the 08/08M except 0V/+V were swapped would Rev-Ed produce a PICAXE-08Y ? Not an easy decision to make considering the nightmare that could cause.

I wouldn't say "don't", but I would say ask opinions having designed something because it's pointless to go into production only to find that the product doesn't sell because the market doesn't accept the decisions made.

If it is just a 'take it or leave it' design being produced it doesn't matter at all what is decided upon. If it's intended to be more generally useful then its design has to be guided by market opinion.

 

[hippy]

It may be obvious but, manufacturing a stamp sized PICAXE board will bring the price up to the me too regions.

We're now getting at the heart of why PICAXE is so popular; its incredibly low price and, being single chip, its ease of use.

That may not be so true in foreign ( non-UK ) lands where shipping can add a huge amount, but compared to the price of competing product it's often a tenth of the price. The competition outside the UK is being eroded by the lower cost Arduino and it will put pressure on the PICAXE within the UK ( outside the educational market ) if it takes off better than it has done so far.

It's easy to point to the success of BasicStamp(TM) but it had almost zero success in the UK through being so over-priced.

In reality there are three markets for people who want an 'easy to use micro' -

1) Those who want a particular product and don't mind paying a lot of money for that. This is where a PICAXE wrapped in a BasicStamp etc footprint could succeed by offering better at a lower cost if it can break brand loyalty, muscling in on others' markets.

2) Those who want the cheapest solution. The PICAXE remains an obvious first-choice candidate there except for people who really have a need for speed.

3) Those who want a cheap but well supported solution. This is IMO where the PICAXE wins hands down, not least because it is usually cheapest but also well supported by Rev-Ed and through this and other forums.

Also consider there are three potential products; the processors themselves ( be that single-chip or carrier board mounted ) and 'application boards' ( be those traditional PCB or all-in-one on a carrier board ), plus the half-way house where just common components are on the carrier.

For a stamp-sized PICAXE carrier board, there needs to be a rationale. If it's just to allow people to use SMD PICAXE it seems largely pointless when they already have cheaper DIP PICAXE's to use, for 'value-added boards' it may be a different matter.

 

[Mycroft2152]

Hippy,

Excellent points.

Even though the PICAXE has a excellent cost / benefit ratio, it is still pretty much a litlle fish in a big pond. Outside of the UK and OZ it is relatively unknown.

I will take exception with your comment about "well supported'. It is only because of the volunteers on the forum that it is well supported. Rev-Ed has been seriously lacking in support, especially in marketing, distribution and documentation.
Don't get me wrong, I really like the PICAXE, but it takes a serious effort to find it and buy it.

The Arduino has come from nowhere, to be a world class and world wide phenomenon. the number of third party vendors for supoort items is amazing.

Rather than embrace the third party vendors, Rev-Ed has been actively discouraging them.


Myc

 

[Dippy]

Well, what is the target market for a BS2? 95% hobbyist and education maybe? 4% prototype/specialist and 1% Meeja Studies Student? A commercial volume user would have to be nuts to use a BSwhatever.

Personally, I can't see anything wrong with a Stamp 2 pinout for this market. It is easy and simple to connect peripherals. And in education you want things simple surely .... "thats why I became a Teacher".

"First to market gets to set the pinout ( for good or bad ), everyone else has to play by those definitions." - absolutely. And if its good then use it. If it ain't broke etc.

The 'market' already buys 10 of thousands of BS2s. There are loads of projects specifically for BS? . The 'market' obviously finds that format acceptable.
Start built-in / built-on goodies and up goes the price. Start fiddling with pinouts then it means further capital costs for making/purchasing project boards and bang goes a pile of sales.

IMHO its not a project that begs for market research, you already know what the market can accept. Make it cheaper and better however, then after that its down to the salesmen.

But everyone, I'm sure, can have and justify a different opinion. Fair enough. You're the experts , not me. I'm bored now and the kettle is boiling.

 

[moxhamj]

The arduino is great too but as far as I can tell, it only is programmed in C.

If you are keen you can buy raw pic chips and your favourite basic compiler and make your own. But you need a pic programmer and the basic compiler and they both cost money. With picaxe, you pay a bit more for the chip but the rest is free. And the picaxe help and instruction manuals are way ahead of anything else out there.

I'm sure a basic stamp format could be replicated, but personally I probably would find it easier to spend a bit of time learning the picaxe format. It is the steep part of the learning curve but it isn't long before you become one of those sad tragic people who know the 08 pinout without having to check the manual.

Maybe there is a market for an adaptor board - maybe not. If Dippy's little board above were available for a few more dollars than the picaxe chip, yes, I would buy it.

 

[hippy]

I will take exception with your comment about "well supported'. It is only because of the volunteers on the forum that it is well supported. Rev-Ed has been seriously lacking in support, especially in marketing, distribution and documentation.
Don't get me wrong, I really like the PICAXE, but it takes a serious effort to find it and buy it.

The Arduino has come from nowhere, to be a world class and world wide phenomenon. the number of third party vendors for support items is amazing.

Rather than embrace the third party vendors, Rev-Ed has been actively discouraging them.

I cannot fairly pass comment on much of that and won't try and defend Rev-Ed beyond saying that they have perhaps been coerced into a market which they'd never intended to get into, supporting general hobbyists rather than the educational sector.

The Arduino has had less success in the UK than the US as they have been hard to find unless importing them. That is changing though. As to third-party support, well it has to have that, there's nothing else ! Otherwise it's just another Datasheet Reference Design from the likes of Microchip / AVR / ARM etc

The Arduino is a credible product but I'm not sure why there's so much hype surrounding it ( except for that 'open source' appellation - "bow down and worship it" ), it's nothing more than a pre-programmed micro with a bootloader and some cross-platform programming software just like the rest. I was turned-off it because of all the nonsense about "processing", "wiring", "scripts" and the Web 2.0-style hype. Seems to be a case of being obtusely different to be fashionable and create a clique which does seem to have captured the mood of many though. AVR with Bootloader plus C and I'd have felt more comfortable - which is what it really is.

Like everything else in the market Arduino has its pros and cons, best choice for a job depends on many factors, we all have our favourites and criteria. What Arduino has shown is what marketing, hype and brand publicity can achieve ( and I don't mean that in a bad way ).

 

[hippy]

The arduino is great too but as far as I can tell, it only is programmed in C.

It's real success is in pretending that it isn't.

By marketing it as a "physical computing platform" and "intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments" they've managed to pull it from the field of hardcore engineering into other areas, the arts and humanities. They've convinced people that anyone can 'play god', make things happen with electricity without being an engineer and made that acceptable.

Full marks for that, it's on a par with Action Man convincing boys it's okay to play with dolls. That's Arduino's real success IMO and it seems to be paying off.

On the other hand there is something rather disquieting about the phenomena. Engineers have been looked down on as a lower sub-species by the so-called higher cultural classes so while they are now also engineers they don't see it that way, they're still artists, but won't except that engineers have equally always been artists, using the skills they are only now learning, so it does perpetuate that class divide and snobbery.

The marketing subconsciously plays on, "you're an artist, so use the Arduino, don't use an AVR (etc) which is designed for grubby engineers", despite the patent nonsense of that. Is that a good or bad thing ? We'll all have our own opinions on that.

Arduino is mostly a social phenomena rather than an engineering one IMO.

 

[Dippy]

"Arduino is mostly a social phenomena (phenomenon?) rather than an engineering one IMO."
- is it?
I never hear it mentioned at the Swingers Parties or at the Basket Weaving classes I go to.

 

[Mycroft2152]

The marketing subconsciously plays on, "you're an artist, so use the Arduino, don't use an AVR (etc) which is designed for grubby engineers" .

Hippy,

Usng your own logic, "Use the PIC, don't use the PICAXE which was designed for grubby students."


Unfortunately, there is more than a grain of truth in that statement.

Myc

 

[MFB]

I certainly agree with Mycroft2152 regarding Rev-Ed's lack of support for the PICAXE. One example being that they do not seem to consider it worthwhile producing application notes that cover topics which generate repeated requests for advise on this forum.

In addition, it is great that Spark Fun is now a US distributor but disappointing that no PICAXE support is provided for their extensive range of products. Spark Fun only supplies example interface code in PIC assembler or ‘C’.

Come on Rev-Ed, this is all basic marketing. For advice on this kind of stuff, take a look at ‘Marketing High Technology’ by William H. Davidow (ISBN 0-02-907990-X).

 

[manuka]

Educationally speaking,I personally find Rev.Ed's PICAXE manuals first rate. Few comparable electronic devices have code snippets & sample circuitry so lucidly shown- sample below. That's not to say things couldn't be better organised of course, as a huge number of Forum pleas seemingly arise from newbies who've not been able to find what they need!

I don't know the marketing clout behind the Arduino, but can verify (via personal visits to Rev. Ed's Bath HQ), that the PICAXE phenomena has evolved from an extremely bare bones outfit indeed. It's amazing that they've achieved so much with so few staff (some P/T)- & their tea-lady is the boss himself. Even us "smell of an oily electron" #8 wire Kiwi's have been impressed!

Dippy- suggest you try Scottish Country Dancing. Isn't an Arduino a type of "2 step" Highland Reel?

 

[Mycroft2152]

Educationally speaking,I personally find Rev.Ed's PICAXE manuals first rate. Few comparable electronic devices have code snippets & sample circuitry so lucidly shown- sample below. That's not to say things couldn't be better organised of course, as a huge number of Forum pleas seemingly arise from newbies who've not been able to find what they need!

I don't know the marketing clout behind the Arduino, but can verify (via personal visits to Rev. Ed's Bath HQ), that the PICAXE phenomena has evolved from an extremely bare bones outfit indeed. It's amazing that they've achieved so much with so few staff (some P/T)- & their tea-lady is the boss himself. Even us "smell of an oily electron" #8 wire Kiwi's have been impressed!

Dippy- suggest you try Scottish Country Dancing. Isn't an Arduino a type of "2 step" Highland Reel?

Stan,

Still following the company line, I see.

I guess you haven;t looked hard enough at the other micros application notes...

You comment have pretty much confirmed that Rev-Edd is a mom and pop level operation using 20 year old surplus chip programmers. hey have found a niche market and are content.

myc

 

[hippy]

@ Myc : And more frequently: use C, don't use Basic or other toy languages.

I have nothing but disdain for that type of snobbery and elitism. There are plenty of reasons why C may be better than Basic but also the other way round, and plenty of scope for rational and reasoned debate. It's the "I'm better than you because I use this" attitude I dislike which boils down to "you are inferior to me".

Moving onto lack of support; what do we each mean by "support" and in which areas is it lacking ?

One thing to ask is whether it's Rev-Ed's job to produce applications notes or not ? Is a manufacturer or bricks expected to produce instructional guides on how to design and build houses, are car manufacturers expected to teach people how to drive ?

Are people expecting more from Rev-Ed than is reasonable to expect or more than is necessary ? That also leads onto marketing; maybe Rev-Ed have all the market they need and are not seeking to massively increase sales in new areas ? There's a lot more to expanding a business than seeing more money roll in the door.

 

[BCJKiwi]

@Mycroft ~ Perpetuating the myth??

Technical debunked the "20 year old surplus chip programmers" myth already;
"We have an operational fleet of 5 PM3000 (DIP devices) and 2 PM2500 (SOIC devices) doing most of the day to day PICAXE programming. We have an almost ever lasting supply of spares - it is often cheaper to buy old machines and extract the spares, and we have done this numerous times in the past. We could quite easily build another full machine from scratch from our spares box! We also manufacture our own programming contacts, the only disposable items on the machine. Our machines are nowhere near 20 years old, machines were manufactured new right up until the late 1990's and available new from stock later still. They were certainly not replaced by the 4000 after 1 year! In fact Data I/O do not make any kind of DIP capable machine any more, so we could not use a more modern machine for DIP parts even if we choose to." ~Technical

 

[hippy]

If Rev-Ed are a mom and pop operation and content with where they are at, is that such a bad thing ? It all depends on what one judges on.

Coincidentally there was similar discussion regarding Parallax Inc as a company a few week's ago. I can see both sides of the coin.

 

[Mycroft2152]

Hippy,

I never said it was a bad thing. My point is that the PICAXE users should not expect the same level of support, innovation. and wide product range from a mom and pop company as compared to a large corporation. There just is not the resources availlable or the mind set to do thses things. Wishing and hoping and complaining will not change that.

Let's just keep out expectations realistic and in proportion.

 

[Craftybytes]

Bloody hell - thread's turned into a 'philosophical' discussion..
I just asked a simple question as to whether any PICAXE users would be interested in a "Stampified" version of PCB format for our venerable PICAXE chips..

If there was enough interest I was looking at making a batch and then offsetting my costs by selling the boards extra to my requirements to those picaxe users who wanted one (at a reasonable cost of course.)..

@Mycroft2152 - (in post #16) -
"I think the closest you will come for a reasonable cost is something like the Boarduino."

Well if you look at the picture you posted of the 'Boarduino' - the PCB doesn't use ANY smd components - if I did one like this for the PICAXE it wouldn't really be worth it in real terms - yes it may be snmall - but one could just as easily use the components on their own designed PCB instead of on this extra board..

However - if the 'Boarduino' PCB used smd components instead - that would be a very different packaging format - more suited to "SMALL" sized applications..

My original question was to ask if any PICAXE users were interested in such a PCB format - since the emergence of smd pre-programmed (bootloader) AXE chips begs for something like this to be investigated..

As to potential costs of such smd based PICAXE boards - well that is a 'yet-to-be-determined' step sometime in the future if the proposal goes ahead - but I would guesstimate that the one off cost could come close to any current existing similar such PCB's (Arduino types for example)..

I think that if there was available "SMALL" format smd based PCB's incorporating say as a 'base' either 20M; 18X; 28X1/X2; or 40X1/X2 PICAXE chip - PLUS a minimal working requirement of xtal/resonator; on-board step-up reg(NiMH batteries)/reg (+5v); programming connector; micro reset switch; RTC chip; and 1 x I2C eeprom memory chip; plus access to all relevant i/o pins - this could form the "basic core module" for any circuit development that the PICAXE chips are used for currently or in the future..

I personally can see one or two of my future projects that definitely would make good candidates for using such "small" format PCB's - surely there must be other PICAXE users out there in the same category..?

Just my 2c's worth of ranting..

crafty.
.

 

[Dippy]

This RedHerringisation or tangentification happens quite often Crafty - quite funny isn't it. I'm surprised we haven't got onto politics and feeding the World.

Yeah, I think we get the idea of your proposal.
I think a lot of people agree, generally, that a PICAXE+basics on a single small board would be quite attractive.
Trouble is the balance between what-to-stick-on and cost is tricky, hence the suggestion for a Stampified unit + EEPROM which would be fairly cheap.
If you start adding RTCs the price goes up. All said before.
If you start adding lots of things then you're moving from a Stampified PICAXE (cheapish) to a Single Board Computer (not so cheap).

And then there's the cost... do a basic design and get a estimate for, say, 200 off.

My feelings so far: It's a good idea. Its an appealing idea. It would make life easier for the Newbie. But many people here are so tight it beggars belief. Some will spend pounds to save pennies. If its altruism that drives this idea then you're very kind. If its a commercial idea then leave it to someone who can get the bits cheaper AND can market it. Maybe Rev-Ed have done some M.R. and costings and considered it as a no-goer?

"I personally can see one or two of my future projects that definitely would make good candidates for using such "small" format PCB's - surely there must be other PICAXE users out there in the same category..?"
- I'm sure you're prefectly correct. I'm sure there are. But how are you going to find out?
Taking a general view of the responses on this thread, you will see that there are a lot of responses... but from the 'same old faces' including me.
If you'd had 30 keen replies from 30 different Forumites then I'd have said there was some mileage.
If people were really keen then even casual Forum 'Guests' would have registered to express their enthusiasm, so I wouldn't use this as Market Research
Remember, people could Google until they were blue in the face without finding this thread, so they'll never be able to say 'Yes Please. How much?'.
A lot more is required, sadly, than an interesting question on the Forum.

Would I buy one? If I was starting out and it was significantly cheaper than the BS equiv and had a Reset pin then I would. An 18X based baby and a 28X1 based big boy would be my initial thoughts. I find the BS so prohibitively expensive that I wouldn't consider it for a second but it has a market and, IMHO, superior documentation.
Anyway 'nuff said. Good luck.

 

[Craftybytes]

Thanks for that summation Dippy..

Yep - to date there has only been a few Forumites who have posted to this thread showing possible interset - but that shouldn't stop me from forging ahead and putting together a PCB or two using the smd PICAXE chips - even if it is only for my own benefit - THEN if everything works out as I hope - maybe I'll get generous and share (post) my 'final' design() to this Picaxe forum for others to use..etc..

Anyway - to all who did post - thanks for your comments and suggestions - much appreciated..

When I finalise my project - I'll see about posting it to the "Projects" section..

crafty.
.

 

[westaust55]

crafty,

going back to your first post you mention a 40pin arrangement with 28X1 based SMD chip and i2c comms for an EEPROM.

While recognising that this can always be done externally, but with 40 pins available there would potentially be enough pins to consider an on-board i2c based IO expander for another full 8-bit port akin to portc.

Would be compact an a potential advantage but as already said starts to approach single board computer situation. But then my experimenters box has a whole series of small boards each with a chip and a few support components or few of the same chip.

Make sure any onboard EEPROM is at address 0 (unlike the AXE022 for 28X1/40X1) then there is no conflict with using say an AXE110 EEPROM expander board which can hold 7 EEPROMs from address 1 thru 7 inclusive.

 

[Craftybytes]

Thanks for that westaust55..

Idea of an 'on-board i2c based IO expander for another full 8-bit port akin to portc' is worth considering, but as you've already stated "starts to approach single board computer situation" - and at present I'm not keen to go down that track..

I first thought of the idea for a 'small' format smd based PCB for the PICAXE chips whilst playing with the circuit design for my particular project in that the size for the final PCB was a bit larger than I was hoping for - then I thought that if the 28X1 & DS1307 RTC & 24LC256 serial eeprom
chips were put on a smaller PCB as smd - and this board was then mounted as a "core" board onto a 2nd slightly larger 'expansion' PCB loaded with all the other extra components needed for my circuit - then this 'combined' PCB format would have much less "footprint" compared to the original size (even though it would take a little more in height - which is acceptable)..

This "core" board approach made me realise that it could be used on a multitude of other possible 'expansion' boards for other types of electronic circuits - not just for my humble effort..

Also in reviewing my circuit I've worked out a way to actually have both low speed & high speed IC2 i/o links just by using one extra chip - makes it more flexible - and yes the on-board serial eeprom will be at address 0..

Your comments much appreciated..

crafty.
.

 

[Mycroft2152]

Small pcbs with standand circuits are handy tools to heve when prototyping. My workbox, like Westy's is full of them.

I am under no delusions that these pcbs that I have made, have a wide appeal and are marketable, (well, maybe one, the the Stick-AXE, breadbord adapter), but each has a specific value added function and advantage.

A PICAXE "swiss army knife" could be handy in certain applications, but is an overkill in most cases.

I must admit, I have to eat my words, a bit, after seeing the new Stickduino by Stiffle.

http://www.spiffie.org/kits/stickduino/

The added value here is the built in USB interface on a small form factor.

At $20 US for the assembled board, or $5 US for the pcb, the price is very reasonable. That is just about the price of an USB cable.

The price of these FT USB chips has come way down, and they are being built into many devices. It should be possible, practical and economical to do something very similar similar with a PICAXE.

Now, that would be a commercial product.

Myc

 

[moxhamj]

Neat chip the ft232. Low as $2.17 if you want 6000 from digikey, and $3.99 if you only want one. I guess this would be programmed slightly differently. Eg with picaxe you plug a RS232 cable into a board and program the board. With this stick format, you put the board into the usb and program it. But I guess you still then have to put the board in something - eg a motherboard that has relays or sensors or whatever. And then if you are doing that many times, you might need a zero-insertion-force socket on the motherboard.

The whole arduino board comes in at less than a 28X1 chip (in Aus dollars at least), so I guess there is some competition in the marketplace here. My favourite picaxe combo is an 18X and one or two support 08s, which is cheaper than arduino stick. Plus, I'm getting old and set in my ways and I don't want to learn to program C.

Yes, I do believe there is a market for modules in a dip footprint.

 

[Mycroft2152]

Dr A.

I posted the Stickduino by Spiffle as an example of what third party vendors can do with a standard micorprocessor.

There are many possible form factors.

From the same guys at Spiffle they also offer the Iduino and the DuinoStamp.

The pcbs themselves would cost under $1 Us each in quantieites of 250 from PCBCart

Myc