PICAXE features tabular summary

I'm rehashing a summary table (as part of a 20M SiChip article) that shows features etc for the dozen PICAXEs- both past & present. Naturally "disciples" parallels abound, although no doubt yet another will soon justify a bakers dozen 13. I'd appreciate any eagle eyes spotting errors & omissions, & suggesting extras etc. Stan

Stan,
I haven't checked numbers, just intial glance like a newbie thinking of buying a Stamp.

So, if I put my "I've never seen one of these before" hat on, I'd say the following:-

"I/O Pins" should maybe say "I/O pins total". Someone may think "ooooh it's got 14 I/O pins and 9 outputs and 5 inputs. Just what I want."
- then you can never be accused of ambiguity.

ADC. "L=Low". Low what? Maybe a little bullet and a one-line note or ref. underneath?

When you include all the breadboard pictures, are you going to re-shoot them? Let the artist within emerge.... and tidy the wiring

Putting my artistic head on, it's fine though some text looks a bit tight in the boxes e.g. PIC types and the 't' of "Polled Interrupt" has been chopped. Aesthetics...

Stan.
re SMD/ SOIC

post #9

http://www.picaxeforum.co.uk/showthread.php?t=9201&highlight=soic+40x1

All modern versions are now available ex-stock.


Picaxe-20 is Picaxe 20M
e

I'd say drop the 18, 28, 28A, 28X and 40X from the chart. Fondly loved members of the family but now departed.

That also simplifies the ADC (L=Low); mark the 08 as "1x4-bit" ?

Great initiative, just some small lunchtime remarks:

- PICAXE-14M has 2 ADC inputs in "standard" mode (not 3 as you mention), but it is maybe worth mentioning that it has an extended configuration also that allows for 5 ADC inputs (and other things). Maybe the extended mode may be referred to via a footnote? You could even indicate the number of ADC channels as 2(5). This properly indicates the power and flexibility of the PIC12F68* line.

- Is the PIC number for the 20M correct (seems like a relatively old chip to me)?

- PICAXE-20M has 3 ADC channels, not four.

- Maybe worth including a column which indicates the type of *hardware* support for PWM (i.e. pwm, hpwm ore none)? I know the diagram is already quite full, but hardware-supported PWM is important in many apps.

I support the remarks made here previously.

/Jurjen

Would second the removal of the older chips.
Re the ADC - key could indicate L=8bit, H=10bit, and the detail should be xL or xH, or preferably, forget the L code and just put 1 x 8bit or 2 x 10bit etc in the detail.
28X1 has 4 ADC and 40x1 has 8 ADC.

If you really want to get carried away you could include (on a second chart perhaps) the neat little pics of the pin outs for each chip, e.g. those on Manual1 page22 for the 28 series, these tell it all as far as functions available.

Any chance of changing the 14M to say it has 5 ADCs? The extra inputs are a bit of a secret, but once you find the hidden appendix in the manual and unlock the extra pins the 14M suddenly becomes a much more useful beast.

Manuaka,

For both the PICAXE 40X and the 40X1, some missing/corrected data is as follows:

Total I/O pins = 31
Outputs = 8 to 16
Inputs = 8 to 20
ADC = 3 to 7 (there is no ADC4, only 0 to 3 and 5 to 7)

The remaining 9 pins (out of total of 40) are used by Reset, Serial In, Serial Out, two off +V, two off 0V, and two off for the external Resonator.

Thanks guys for feedback! #2 draft below reflects most of these, & I've also removed the column showing total I/O pin numbers. I've a keen sense of technical history, & although those early PICAXEs are obsolete, stocks lurk (especially in schools) & folks may want to know specs. or ID details. Scope for much more detail of course, but I'm aiming this at those who may think there's only a single PICAXE available... Stan

EXTRA: 40X1 memory corrected to 1000 lines- thanks.

The 40X1 has capability/memory for approx 1000 lines of program (same as the 28X1)

I know it seems counter-intuitive but I would move the 20M between the 14M and the 18A as the 08M/14M/20M are more closely related to each other and this positioning will help readers pickup the family resemblance between these chips.

Good point & I agree- will consider.

I agree - Also size of program and rising cost are then ascending ( results of being from the same base family ).

As only the 08 doesn't have polled interrupts, would it be worthwhile replacing that with maximum MHz speed ?

Your feedback appreciated- draft #3 below the outcome. I've also added spaces for the TBA 28/40X2, plus speeds & intended application. The whole thing, which increasingly reminds me of a gigantic organic chem. pathways overview I made -mumble-35 years back, needs re-typesetting of course, as presently rather a mix of styles. Stan

Spotted two factual errors -

1) Not all PICAXE's run on 3V-5V ...

4.5V to 5.5V = 28X1 (16/20MHz), 40X1 (16/20MHz)
4.2V to 5.5V = 28X2, 40X2
4.0V to 5.5V = 18A, 18X, 28, 28A, 28X, 40X
3.0V to 5.5V = 18
2.2V to 5.5V = 08
2.0V to 5.5V = 08M, 14M, 28X1 (4/8MHz), 40X1 (4/8MHz)

2) The trademark attribution is wrong ...

" PICAXE® is a registered trademark licensed by Microchip Technology Inc." is what Rev-Ed use, so presumably the official, sanctioned, definitive statement.

"PICAXE is a registered trademark of Microchip Technology Inc. licensed to Revolution Education Limited" is what I've used to make sure Rev-Ed get a name drop.

I also steer clear of mentioning "PBASIC" and similar because that's a trademark belonging to Parallax Incorporated.

PICAXE features tabular summary - Trademarks

Hippy,

With respect to the Trademarks, while the footer on the Revolution Education Limited home page supports what you say I wonder if there is a typo.

Now I may be barking up the wrong tree and there may be things I cannot find but . . .at the Microchip website I see/find no reference to PICAXE. As I see it, Microchip Technology manufacture the PIC chips and Revolution buy then pre-programme them with an interpreter and badge them as PICAXE.



Searching for PICAXE and the Revolution Education Limited website I see:
PICAXE microcontrollers home site www.picaxe.co.uk.
Using this link changes to http://www.rev-ed.co.uk/picaxe/

On the Revolution homepage it states:
PICAXE® products are developed and distributed by Revolution Education Ltd
PICAXE® is a registered trademark licensed by Microchip Technology Inc.

However,
A search on the Microchip Technology website using “PIC” finds many entries.
A search on the Microchip Technology website using “PICAXE” finds no entries.

Also from the Microchip Technology website about their trademarks:

The following are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries: Accuron, dsPIC, KEELOQ, MPLAB, PIC, PICmicro, PICSTART, PRO MATE, rfPIC and SmartShunt; as well as the Microchip logo, the Microchip name and logo, and the KEELOQ logo

The following are registered trademarks of Microchip Technology Incorporated in the U.S.A: FilterLab, Linear Active Thermistor, MXDEV, MXLAB, SEEVAL, SmartSensor , and The Embedded Control Solutions Company.

The following are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries: Analog-for-the-Digital Age, Application Maestro, CodeGuard, dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN, ECONOMONITOR, FanSense, ICEPIC, ICSP, In-Circuit Serial Programming, Mindi, MiWi, MPASM, MPLAB Certified logo, MPLIB, MPLINK, mTouch, PICDEM, PICDEM.net, PICkit, PICtail, PIC32 logo, PowerCal, PowerInfo, PowerMate, PowerTool, REAL ICE, rfLAB, Select Mode, Total Endurance, UNI/O, WiperLock, and ZENA.
SQTP is a service mark of Microchip Technology Incorporated in the U.S.A.

Back in 2005 Rev-Ed said;

And in 2006 they also said;

So I guess that covers it!

PICAXE Trademark

Thanks BCJKiwi,

As you say, that covers (explains) it well for all.

The 'official status' of the PICAXE trademark ownership and history are here ...

http://www.ipo.gov.uk/tm/t-find/t-find-number?detailsrequested=C&trademark=2388482
http://www.ipo.gov.uk/tm/t-find/t-find-number?detailsrequested=H&trademark=2388482

Stan... "each pin can source sink 20ma" - isn't there a total that the chip can handle less than all pins going full blast? I use external drivers so haven't kept track of this but seem to recall come caveat about total current the chips handle on the Vcc input.
Thanks for the good summary table!

I think it's generally 100mA per port. Some ( most ? ) PICAXE's support 25mA per pin, and some may support 200mA per port; would have to check each datasheet.

PICAXE features tabular summary - current loadings

Using the datasheet for my trusty 40X1, the electrical specs state:


Maximum current into Vdd = 95 mA
Maximum current out of Vss = 95 mA

Maximum current sunk by all ports (combined) = 90 mA
Maximum current sourced by all ports (combined) = 90 mA

Maximum current sunk by any I/O pin = 25mA
Maximum current sourced by any I/O pin = 25mA

I think that some refinement is needed on hippy's comment that the 18X operational voltage range is 4.0 - 5.5 V. This is certainly true if programming is concerned. However practical operation is in the 2.0 - 5.5V range, although the serin/serout timing appears to depend on the voltage level, sometimes requiring the calibfreq command to be applied. This can of course not be done for program download, and thus a minimum of 4V appears required for programming.

/Jurjen

OK on supply. Since all PICAXEs are happy with the industry standard 5V I've just modified the table to say "~5V", implying things are not too critical. 4th Draft below looks to have nailed all issues raised, although it's been tweaked & re-saved as a .jpg so fuzzy text is apparent. If this looks OK I'll re type-set. The motivation for this is educational to inform folks about features & offerings "at a glance", & it could suit an enlarged classroom wall chart. Copyleft of course. Stan

Caution!

The ~5v can be easily interpreted as 6 volts is OK.

One more correction, the X1 and X2 parts can also run much slower than 4 MHz, without any tricks (just use setfreq). So the table should probably say "32kHz-20MHz" for the X1 parts, and "32kHz-40MHz" for the X2 parts.

I think for a total newby that the Inputs / Outputs is a little confusing.
Can't you indicate Inputs(Fixed), Outputs(Fixed) and Configurable I/O ??

First glance at the 08M implies it has 1-4 Inputs and 1-4Outputs, true, but it could be read as up to 4 inputs and 4 outputs. Put yourself in the place of a newby or inexperienced teacher.
In reality it is 1 fixed Input, 1 fixed Output and 3 configurable I/Os.

It's a good little summary table, though artistically the lines are a bit too bold unless the final copy is in colour and a mid-blue would be nice. You don't want to visually distract from the text.

Finally, I've got a hangover, but what does "Data Memory" and the descriptions mean? Sorry, but my head is really fuzzy this morning. Therefore I'm viewing it as a Newby and haven't got a clue what it means?? 256+i2C - what's that then?

As manufacturers are quick to delete any data concerning an "obsolete" device, in order to sell more of their new line, I think it would benefit the holders of many of the older parts to have as much data as can be obtained. So leaving the information in your chart(s) seems, to me, the best choice. That part of the chart would not need updating unless to move another obsolete device into it.