Is my Picaxe Blown?

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MikeV

New Member
Is their a way to test a Picaxe chip (18x in my case)?

After building a Axe Stack kit, i am unable to connect to the chip with the software (with many machines).

I can test a voltage in the Serial in Pin with the sofware, but not communicate. I'm afraid i blown my chip anyhow...

Tested with a prolific adapter and with a real com port.

Any help would appreciated :)
 
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Steve Joblin

Member
I know it kind of an obvious response, but do you have another Picaxe you can replace it with? Do you have a breadboard where you can build the simple download circuit and see if you can download a simple program to blink an LED?
 
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BeanieBots

Moderator
Does the previously downloaded program still work?
The simplest test is a firmware check but that does assume a working download circuit and power supply.
 
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MikeV

New Member
I'm a newbie in microcontrollers. This is the first time I tried to make it work.
Still, i get a signal (+6v) betweens pins 3 and 5 and voltage (5.2v) between pins 4 and 14.

If a build a test board, what more should I add?

Unfortunately, I do not have another 18x at hand. I will eventually order another, but not if I can avoid it for now.
 
hippy

hippy

Ex-Staff (retired)
What's an "Axe Stack" kit ?

Have you managed to program anything into the chip at all ?
 
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BeanieBots

Moderator
Before we all start second guessing, maybe should tell us what you have done so far. Please be honest.
What power supply have you EVER connected to it? What voltage?
Has it EVER had the polarity reversed?
Has the chip EVER been inserted the wrong way around and powered?
Anything else you think might be important.
 
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MikeV

New Member
the AxeStack has a built-in voltage regulator and reverse-polarity checker.
The PS pushed 9v (11.4v without load), but I mesure only 5v at the + pin on the chip, so i guess the voltage is OK.

As for the socket, there is a key the show the right way, i did not plug it wrong side

I bought the Axe Stack because it seemed dummy-proof. i'm now officially dummy-proof-proof :)
 
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BeanieBots

Moderator
Unlikely it's dead then:)
Probably a comms problem.
Double check all your soldering and check for any bridges.
Does the PICAXE get warm or is it stone cold?

Unfortunately, that board is not an "official" Rev-ED one so there is no support for it (ie diagrams or proof it ever could work) but the site looks OK and would expect it does work.

It is always possible that you have a DOA chip but that is so rare (especially with the 18X) that I would only consider it as the very last option.

You mentioned 'prolific'.
Are you using a USB adaptor? If yes, is it a Rev Ed adaptor or some other third party device?
Have you tried the USB comms test?
 
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MikeV

New Member
The Pickaxe stays stone cold.

At first I used a usb-to-serial adapter with a Prolific chipset, but to be sure I tried on a com port of a desktop pc. No go.

I did the usb test and the result are positive. Signal does go to the chip...

i'mjust about to give up and order a pre-built board and another Picaxe... :( But first i'm gonna test with a minimal circuit on a prototype board.
 
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M

MikeV

New Member
Yeah i saw that. I even tried my adapter with both the driver for usb010 and a
direct download from Prolific.
I did a great deal of home work before asking for help. :)
 
B

BeanieBots

Moderator
Stone cold is good. At least no outputs are shorted.
Go for the minimal circuit.
Just remember, the download circuit is NOT a potential divider.
The 18X MUST have its reset pin held high. (ideally with 4k7 but a link is OK).
Use 3 X 1.5v batteries for power.
 
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manuka

Senior Member
Since making their 2002 "discovery",I've not lost a single PICAXE of any type -these little darlings are near bullet proof. As you apparently have a serial fitted PC, it's suggested (come in Dippy) that you just rustle up a simple breadboard test circuit for the 18X & try simple code to flash a few LEDS etc. Check => http://www.picaxe.orcon.net.nz/keyb18xa.jpg which shows a 2003 layout intended for keyboard work, while =>http://www.picaxe.orcon.net.nz/datds18.jpg has a temp sensor.

Of course,if you are new to PICAXEs, it's STRONGLY RECOMMENDED YOU START WITH A 08M to get a feel for things....
 
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moxhamj

New Member
I'm going to second Manuka's suggestion of going with an 08M. My first picaxe was an 18X and it was complicated and took a while to get going and because it was expensive I only had one. I very rapidly moved over to 08Ms and now buy them in rows of 10. It is very helpful to swap chips back and forth. I use a breadboard that is 25 years old and still working. I even use 08Ms to debug subroutines that ultimately end up in bigger chips.

One of the commonest "dead chip" scenarios is a chip where a serin has been programmed and the chip is hanging. The answer is to cycle the power, and another trap is not to have too large a capacitor next to the chip otherwise cycling the power to the board doesn't actually power down the chip. My setup is 33uF, 0.1uF and 1k across the power supply pins of the chip. This is just for programming - working chips don't have the 1k.

But you haven't even managed to program a chip so it is unlikely to be the serin problem. It could be the download resistors are wrong. It could be the -12V from the RS232 has zapped a chip.

Can you take a digital photo of both sides of the board and post them on the forum - usually in the past someone spots an error very quickly.
 
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MikeV

New Member
I guess you are right, guys. I ordered a couple 8m and a board. Maybe the little 8 pins bug seemed too little impressive at first, but let's walk before running. :)
 
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manuka

Senior Member
We await your impressions! I also buy 08Ms by the crate load, & even after 4 years confirm their A1 horsepower means diverse electronic depths still remain to be sounded. Stan
 
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T

Tom2000

Senior Member
Mike,

I also bought a couple of HVWTech Axe-Stack modules -- one 28X1, and one 18X. As soon as I bought them, I ran into some weirdness in the download pinouts at the 3.5 mm jack.

Are you using the RevEd download cable that has the correct (weird) pinouts, or have you fabbed a download cable?

I discussed the pinout problem in this thread.

Don't give up yet. Those modules are pretty cool. It behooves you to get yours up and running.

Good luck!

Tom
 
M

MikeV

New Member
Well, I got the cable that was sold with the stack. More news when I get my 8m.

Argh! I just can't wait. :eek::(
 
D

Dippy

Moderator
Did you check the PCB socket, compared to PICAXE connections to make sure that socket connection is OK? (Checking for physical connection and PCB accuracy).

Have you contacted the supplier/manufacturer?

Did you try a breadboarded download circuit with a socket? A lot of people get the jack socket / leadout wrong.

(I think the 08M is great little thing. But I must admit I started with the 18X, mainly because it had a reset button.)
 
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MikeV

New Member
Heaven!

I received my 8Ms today, soldered the kit, tested it on a PC and... wow it works! Boy the fun I'm gonna have with this!

Anyway, if this can help somebody, my goal was to use this kit inside Parallels with a Macbook. With a Prolific chipset on the USB to serial adapter, it works.

Thanks guys to suggest to begin qith a 8M.
 
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