PICAXE ? PICmicro ?

[hippy]

We seem to get quite a few problems with people who cannot download which are coupled with their not being entirely sure if they have a PICAXE or bought / received a blank PICmicro by mistake. Almost impossible to resolve if it stubbornly won't work.

How about pre-loading PICAXE's with a program so they flash a LED with some obvious pattern ( maybe morse ) when first powered-up ?

At least that way we can determine if they actually have a PICAXE to start with. If they've never been able to download it is unlikely they've ever over-written the factory delivered program. It would also be useful to everyone just to confirm a PICAXE was working even before trying download.

The only risk is that someone could connect a PICAXE straight to hardware, turn it on and find this damaged what hardware they had because this behaviour wasn't expected. I think that's minimal risk anyway and anyone who has designed something like that is simply storing up trouble for themselves in the future. Potential damage can be minimised by only doing this flashing for a short while after turn-on or reset. Serial Out can be toggled AFAIR on all PICAXE so that would be a good candidate with minimal risk. The program doesn't have to just flash a LED, it could also send a message which can be viewed using Terminal, that would prove the connection was okay even if download wasn't working.

The only other design criteria is that the LED flashing program doesn't use Pause or anything which requires the device to be reset or power-cycled to allow the first download.

 

[alband]

Wonder if anyone could create a way/program of transforming a PIC into an AXE?
That would be useful.

 

[moxhamj]

I like the idea!

Could a flash be combined with a message? IE it sends back a message using serial out (pin0 on the 08M etc), and then the debugger displays a little message. Could be a test item on the menu. And it could flash a led too if you connect one. Or it could be as simple as a program that pulses that line twice a second, and the download software can look for 1/2 second pulses.

One could imagine a wizard that runs automatically the first time the software is installed on the PC, and steps through "connect plug like this", "connect chip" "chip is connected and ready for download" or "chip is not communicating". And a link to re-run the wizard in the future.

The wizard could have photos so it is really easy to understand.

The first download would overwrite the flash program, and the wizard would only run once, but I've found getting it working first time is the hardest - after that it almost gets hard to not get it working. So this could help get people hooked on picaxe right from the beginning!

 

[Charliem]

Wonder if anyone could create a way/program of transforming a PIC into an AXE?
That would be useful.

Rev_Ed has already done that.Its called a Picaxe


Hippy thats a great idea.

 

[steliosm]

hippy, Dr_Acula that is very good idea. In the simplest form the PicAxe can just output through the serial port the chip type and the firmware version. You don't even need to breadboard the chip if you have bought a prototype board along with the chip.

 

[Dippy]

Sounds good.
Great comment Charliem... you saved me having to be sarcastic

 

[moxhamj]

Steliosm - good point. It already sends *something* back - eg if I put in an 08 instead of an 08M it will give a message saying to insert the right chip. But not sure if that applies to all the chips.

 

[papaof2]

Technical has said that the the paper label machines don't work well, but rubber roller offset printing or a mechanized rubber stamp could print the chip type on each chip. That at least resolves the PICAXE vs naked PIC question.

Having the chip type and firmware version sent out serially at powerup provides verification of good power and that at least 3 connections are correct (+V -V, serout).

Both of these require additional processing (printing on chip, loading a program) which would impact production costs. Since the bootloader has to be installed on each chip, adding the ID program should require minimal changes to the production process.

John

 

[hippy]

I think we have to accept that if Rev-Ed says it's not easy or too costly to do labelling or printing then that's the way it's going to be, at least for now.

One of the nice things about the way PICAXE does its comms direct to a PC with no interface is that it's quite easy to embed a text message within or alongside a LED flash. There's a bit of 'flicker' seen on the LED but it shouldn't be too confusing. That's a handy trick as well if you need LED status and serial and I/O lines are in short supply ...

#picaxe08m
Do
  SerTxd("Hello")
  High 0
  Pause 500
  Low 0
  Pause 500
Loop

 

[Technical]

To be honest we don't understand the logic in this...

By far the main trouble newcomers have is with the setup of the correct serial communications, home made cables, virtual COM port, correct power supply etc. etc. If the setup is all correct the program will download anyway, so there is no need for anything else.

If the setup is incorrect then the sertxd won't work either, so there is no point in having a sertxd line preprogrammed in the chip! Additionally a 'firmware check' already provides a method of testing communication with the PICAXE.

We are also against the idea of providing a chip that may unexpectedly do something that is not expected, e.g. switching an output on and off. The user decides that, not us - we don't know what may or may not be connected to that output!

 

[hippy]

I think that's the problem ... if it works, then that's hunky dory, when it doesn't they want help.

True, if the PICAXE is badly setup they won't get anywhere, but that at least halves the issue; "forget your download problems look at your hardware". The Firmware Check only works when both input and output are wired correctly, if there's a way to tell at least output is working then it halves that issue as well; "Check your Serial In interface, is the 10K at the wrong end of the 22K ?".

It was really trying to find something which would help people lead others through to solving what their problem is rather than being stuck with, "it either works or it doesn't, and if it doesn't you've done something wrong". It's towards helping find what that wrong is.

We can all churn out the long checklist of what could possibly be wrong, but it just seems more useful to me to have anything which could help lead people to a quicker resolution of the problem before they throw it all in the bin.

I do agree with the issue of a PICAXE doing unexpected things, but using Serial Out would alleviate that almost entirely, and its behavior can be fully documented.

 

[boriz]

I vote rubber stamp.

 

[medvampire]

I have a board for 08M and 14M set up that I pop chips in when I get them, do a quick test, clear the chip and they get popped in to a box with the chip type on the box. I really dont like the ideal of a program being loaded on the chip. The project I am working on right now has a 300 mw laser connected to it and I don't want that thing going off uncontroled. I started about 4 months ago with bare chips and the software and learned to build the interface but I did fry a 08M in the process. Killing a chip or two is part of the learning process and I have quickly learned to play with the cheep stuff, learn and then move on to the more costly chips. The down load circut is very simple and newbes (myself included) need to master this circut with the smaller chips before they move up to bigger projects (imho).
Steve

 

[hippy]

I think those who don't feel the need for such a thing should dive-in and help people out when these problems arise because I'm sure they'll gain a new perspective.

@ medvampire : But as you'd never power up a PICAXE without having taken all necessary safety precautions because mis-configured or faulty software could cause exactly the same disasterous effects it wouldn't really be an issue. As you have no guarantee (*) what a PICAXE will actually do when first powered up when it arrives I presume you have precautions against that so it again wouldn't really matter.

(*) Rev-Ed can offer any guarantee they wish on what leaves their factory, but that's not a guarantee it hasn't been affected by ESD or other external corrupting influences during transit.

 

[hippy]

<sarcasm>

Can you imagine teaching people to drive this way; giving them blind driving instructors ?

</sarcasm>

 

[manuka]

I'm with Technical on this, but simply attach your own labels as they arrive of course! This Forum has no doubt become SO well versed to me saying this, that my usual URL will be omitted ...

BUT -

I really dont like the ideal of a program being loaded on the chip. The project I am working on right now has a 300 mw laser connected to it

YIKES-I'm more than a trifle concerned about this, as here in NZ even a few mW of green lasers pointed at aircraft have been enough to land the rascals in jail. 300mW is close to a WMD (Weapon of Mass Destruction). PICAXEs are intended for educational purposes!!

 

[Dippy]

Before we reach the usual 'panic stations'....yawn....

I think hippy's idea was that a little bit of pre-loaded software (I assume overwritten on the first programme??) could be used to test to see if the little thing with legs that you've just received was actually a PICAXE and not a blank PIC.

As the device is NOT labelled at source then there could be a muddle (or other cockup) by the distributor/retailer.

I assume the idea is that when you open your envelope you could pop the thing-with-legs-but-no-label into a breadboard (hey Stan), pop a LED+res on the serial out pin, switch on and see if it flickers.... then connect to PC serial and see if something pops up to your PC. A simple sertxd could do that. A one-off one-line straight after power-up or reset. If nothing happens then there are 3 options; A) it ain't a PICAXE, or, B) you can't read a data sheet to see the pinout, or, C) It's broken [...but by whom?]

It will not prevent damage due to user incompetence but at least careful users can ID the product straight out of te box.

Good idea, where's the drama?
Surely medvampire doesn't have his 300mW Stan-blinding laser connected to serout? Are we makng the usual mountain out of a molehill?

This would also mean Stan could post some more pictures of chips in breadboards...

It'll never get done but it's a nice idea.

 

[BeanieBots]

I was about to say let's take a vote and then setup a poll, but I can't find the poll feature anymore
Anyway, I'm all for an ID feature sent out on the serial out pin. Even if it is just a simple LED pulse.
If anyone has a "mission critical" device that is controlled by output0 on an 08M which cannot be dissabled when a brand new PICAXE is plugged in, well, quite frankly (and quite rightly), Darwin will take of that!

 

[manuka]

.Well said Dippy (for an Englishman)- you should be in politics. But- gasp- perhaps you are ?

I've sourced -via Rev. Ed directly (+ Oz & NZ agents) thousands of PICAXEs over 5 years (mostly 08Ms & 18X) & have yet to have a failure of any kind on arrival. As they're unpacked I hence asume they'll "just work", & following a personal site visit to Rev. Ed's Bath HQ in 2006, I remain more than happy about their QC.

The 300mW laser reflection arose from considerable recent local NZ comments re. mischievous use of even 1mW coin shop offerings. Stan

 

[medvampire]

No I don't have the laser tied to pin 0 but I do have a safety led tied to that pin. The laser is tied to pwmout through a optocoupler and power transistor on pin 2 of the axe 08M. It is part of a laser cutting table. I should have the project in done here in a few weeks and posted in the finished thread.
Steve

 

[gengis]

I don't see the need but with the numbers of chips Reved buys they could probably get them "house numbered" for no cost.

Another idea might be these stencil paint gizmos - they are for marking cloth and have pigmented paint in colors and a broad felt tip (more like a stamp pad) for dabbing. Just color code the surfaces.

I haven't see them since I left the navy - but haven't looked either,

 

[hippy]

I think hippy's idea was that a little bit of pre-loaded software (I assume overwritten on the first programme??) could be used to test to see if the little thing with legs that you've just received was actually a PICAXE and not a blank PIC.

Spot on, exactly that. Not much more than pre-downloading the, "You've got a PICAXE, now let's try flashing a LED", first ever program we'd probably recommend a newbie to try when they get their first PICAXE.

When you have a PICAXE and it won't download you have numerous possibilities which could be wrong and you have to check everything and when everything is all okay it will work, until then it 'does nothing'. It was really just a suggestion to allow it to be easily said that "at least that works" which drastically helps cut down what the possible mistakes have been, saves effort all round

Draw out the flowcharts or step-by-step testing needed for remotely diagnosing a, "I cannot download to my PICAXE" problem, and it's much easier with this LED flashing and message reporting pre-loaded than without, where a result only comes when everything is right.

 

[hippy]

Here's the flowcharts -

As now : http://homepage.ntlworld.com/the.happy.hippy/picaxe/noled.jpg

As proposed : http://homepage.ntlworld.com/the.happy.hippy/picaxe/withled.jpg

It's notable where what can be definitively said about the PICAXE working falls ( the green boxes ). The current process is more about establishing that it should work, rather than what parts of the configuration do work IMO.

That's my last word on the matter.

 

[boriz]

I always have a LED on Serial Out while prototyping/testing. Standard practice. Sometimes I also use a Piezo speaker so I can hear the comms. Also standard practice: I always leave the AXE switched off until the ‘Connecting to hardware’ programming dialog comes up. Only then do I power the AXE.

I see no benefit in pre installed flashing routines. I prolly wouldn’t even notice.

A nice “14M” stamped on the package though. That would be useful. Especially if it was actually a 14M.