Programming issues.

[skoeba]

If anybody can help me with this problem is would really appreciate it.

I'm trying to program the PICAXE-14M using USB to serial converter, to no avail. I did the USB test in the options menu in the PICAXE IDE and it works as intended. However as soon as i try and program the the pic i get a list of errors, from possible incorrect frequency selection to a possible blank microcontroller. I dont know what the problem is, my usb to serial converter works, i've tested it on hyperterminal. The program im trying to run is quite simple, all i do is switch on an LED as a start to see if i can program the pic.

Do i need to use the AXE026 serial programmer specifically or could i possible have bought a blank micro controller? (I'm using the PIC16F864)

Any help out there?

 

[MartinM57]

What did you actually buy?
- a PICAXE-14M from a PICAXE supplier
- a PIC16F864 from any old electronic component supplier?

You need the first one - the second will not work (it is not a PICAXE-14M until Rev-Ed have pre-programmed the PICAXE firmware into it. which you cannot do yourself)...

EDIT:and what USB converter are you using? The official AXE027 USB cable (guaranteed to work) or any old USB-Serial cable (which is not guaranteed to work)?

 

[tiscando]

(I'm using the PIC16F864)

Welcome to the PICAXE forum.

Have you installed the minimum operating circuit in the PICAXE manual 1? Also, what power supply are you using to power the PIC?

Do you mean "PIC16F684"? It is the PIC used for the PICAXE 14M, in terms of the PICAXE manual 1.

To test if the PIC(AXE) you bought is actually a PICAXE, and is working:
connect an LED via a 470 ohm resistor, to the PICAXE's serial out pin and 0V (Gnd);
Power the PIC up to 4.5V or 5V (3 AA batteries are ideal);
connect a 470 ohm resistor to the serial in and +V (4.5v or 5v);
Does the LED flash? if not, then (presuming you have connected the circuit correctly) it is likely to be a blank PIC.

 

[skoeba]

Programming issues

To be honest I'm not sure if it is in fact the correct pic. What i do know is that the guy who i am doing the programming for was suppose to buy the PICAXE-14M, upon reading the PICAXE Manual 1 I saw the part number of the PICAXE-14M corresponds to PIC16F684 and it also written as such on the micro controller itself thus I'm assuming that he did in fact buy the correct chip. However I know the possibility exists that he might have unknowingly bought a blank PIC.

Thank you for your advice, I'll do the test you recommended and get back to you. one last question, is that all i need to connect? No serial connection to the PC? just the two resisters and LED.?

Regards Skoeba.

 

[MartinM57]

To test if the PIC(AXE) you bought is actually a PICAXE, and is working:
connect an LED via a 470 ohm resistor, to the PICAXE's serial out pin and 0V (Gnd);
Power the PIC up to 4.5V or 5V (3 AA batteries are ideal);
connect a 470 ohm resistor to the serial in and +V (4.5v or 5v);
Does the LED flash? if not, then (presuming you have connected the circuit correctly) it is likely to be a blank PIC.

I'm intrigued - how does this verify you have a PICAXE?

 

[hippy]

@ MartinM57 : I'm intrigued - how does this verify you have a PICAXE?

It simulates a download initiation so the LED flickers with the download mode acknowledgement. It's a reasonable test of blank PICmicro versus blank PICAXE, especially if done after a Hard Reset, ie, with Serial In pulled high the LED should flicker when powered up or released from reset.

It's not fool-proof if there is some other problem or 'whatever it is' has been programmed already.


@ Skoeba : You did not say what type of USB-to-serial cable you are using. The serial cable needs to support 'break signalling' and not all do. Even though it may work in HyperTerm it may not be suitable for use with the PICAXE. That the Serial Port test works suggests that the cable is suitable.

I would therefore suspect that it may be a blank PICmicro which you have bought rather than a PICAXE.

 

[MartinM57]

...so it doesn't matter what you have the Reset pin connected to (the instructions don't mention it, so I wouldn't connect it to anything)?

 

[skoeba]

Ok so I did the test you recommended tiscando and the LED does indeed flicker, suggesting as you said the chip indeed the PICAXE-14M.

That leaves me with only one alternative, i need to find another serial port to test with and if that fails i guess i need to aquire the PICAXE serial programmer. Unless anyone else has any other suggestions. However i really hope another serial cable works as ordering parts from the UK takes forever to get here.

 

[hippy]

...so it doesn't matter what you have the Reset pin connected to (the instructions don't mention it, so I wouldn't connect it to anything)?

You need a complete PICAXE minimal setup, power, reset, download circuit, crystal as appropriate. LED+R on Serial Out to 0V, then pull Serial In to +V.

 

[hippy]

Ok so I did the test you recommended tiscando and the LED does indeed flicker, suggesting as you said the chip indeed the PICAXE-14M.

As it seems to be a PICAXE, the Serial Test apparently works, then it will be worth double-checking your wiring is correct. You can also try the USB cable on another PC or find a PC with a physical serial port and try that.

If you tell us the manufacturer, make and model of the USB-to-serial cable there may be better advice which could be given.

With the LED+R on Serial Out as in tiscando's test, does that LED also flicker when you perform the Serial Test and turn the on-screen LED on ?

if that fails i guess i need to aquire the PICAXE serial programmer

That probably will not really meet your requirements.

Best to determine if you have a PICAXE chip ( there should be an order acknowledgement somewhere with part numbers shown ) and have a suitable USB cable first.

 

[skoeba]

Programming issues

Thanx for the advice guyz, it would seem as the problem does in fact lie with my usb-to-serial converter because i tried programming it from my PC at work using my serial port and it was successful. I also tried it again using the usb converter but no success.

I like this forum, it has the best advice and fastest responses i've ever come accross. Once again thanx, now i can continue with my project...

 

[manuka]

Skoeba: You DON'T need much processing horse power to program PICAXEs! Aside from Apple & Linux approaches, any W95 & up PC can be used to run the program editor, so perhaps just grab some oldie serial fitted laptop for the job.

I've a swag of 8-10 yo. (& hence shot battery) 200MHz Win98 Toshiba 480CDTs I use here in NZ schools for this. Even when organised 5 years ago, their average price was just ~US$20. You must have any number of similar lurking in Namibian cupboards! Aside from a D9, about the only extra requirement I'd look for is a USB port to allow memory stick file transfers. Most PCs made since ~1999 supported USB of course, but older ones without it may lead to hassles transfering files.

See diverse skin flint PICAXE ideas in this vein => www.picaxe.orcon.net.nz Stan.

 

[skoeba]

Thanx man, ill check it out. Finding an old PC with a serial port shouldent be that difficult, il start looking around...