Programming difference between new and old version

[VK5OQ]

I am attempting to download a programme written using the latest version of the Picaxe editor (5.2.6) I'm using a cable equivalent to the old AXE025 with 3 in-line pins. The hardware works when I use the old version of the Picaxe editor (4.1.9) I can download an old programme to the picaxe but when I use the same hardware with the later version it doesn't work. Testing the serial connection with the test facility in the latest version under the Options menu checks out OK. Any ideas?

Keith

 

[Andrew Cowan]

What PIC are you using?
What power supply are you using?
Is it a project board, a homemade board, or a breadboard?

A

 

[SilentScreamer]

Also:

Which error message is shown?
Does the firmware check work?

EDIT: Welcome to the forum

 

[hippy]

Welcome to the PICAXE forum.

When you say it works with 4.1.9, have you confirmed that worked immediately before and after trying 5.2.6, or is it a case of used to work some time in the past with 4.1.9 ?

 

[VK5OQ]

The PIC I'm using is the 28X
The power supply is a home made regulated bench supply set to 12 volts and using an on-board 5 volt regultor.
The circuit is built on a commercial prototype board.

 

[VK5OQ]

The error message shown is "Error - hardware not found on COM 1".
I haven't tried the firmware check. I will do.

 

[VK5OQ]

Welcome to the PICAXE forum.

When you say it works with 4.1.9, have you confirmed that worked immediately before and after trying 5.2.6, or is it a case of used to work some time in the past with 4.1.9 ?

I first tried to download the program I wrote using the new version 5.2.6 and I got the error message. Then I tried downloading an old program to the 28X using the old Picaxe Editor 4.1.9 and it worked. It's almost as if the baudrate is wrong or some such.

 

[BeanieBots]

Double check that your comm port is set to the same value you had in the old version.
View->options->serial port

 

[VK5OQ]

Double check that your comm port is set to the same value you had in the old version.
View->options->serial port

Comm port settings are the same, 9600bps, 8, 1, no parity, no flow control.
When I click the Firmware? button with new version I get the same "Error - hardware not found on COM 1" message. Doing the same with the old version, I get
"Firmware version 7.8
Picaxe-28X Firmware version 8"
Do I need a more recent version of Picaxe firmware to run with version 5.2.6 of Programming Editor?

 

[eclectic]

Just a possible?.....

What value crystal/resonator do you have?

Also, check

PE >> view >> Options

as in pic below.

e

 

[Technical]

You should be able to use with either, there should be no difference. Note that if you have one version open you will not be able to use the other as serial ports cannot be shared ie shut down one version before trying to use the other.

Have you tried a hard-reset of the chip (release reset when progress bar is on screen)?

 

[hippy]

Firmware Version 7.8 should be compatible with the latest Programming Editor. Make sure you have got 28X-40X and the correct 4MHz/8MHz/16MHz speed selected as per eclectic's image.

 

[VK5OQ]

Just a possible?.....

What value crystal/resonator do you have?

Also, check

PE >> view >> Options

as in pic below.

e

Thanks for the replies. 16 MHz crystal in the circuit and that is the selection on the options page. The firmware version being out of date would explain what I am seeing. I had the 28X's on hand but seems like getting a 28X2 is the way to go.

 

[VK5OQ]

Firmware Version 7.8 should be compatible with the latest Programming Editor. Make sure you have got 28X-40X and the correct 4MHz/8MHz/16MHz speed selected as per eclectic's image.

firmware version 7.8 being capable of working with the latest version of PE puts me back to square one. Time for bed in Adelaide, Australia.
I'm fairly sure I shut down one version of PE before trying the other. Will try again.

 

[VK5OQ]

You should be able to use with either, there should be no difference. Note that if you have one version open you will not be able to use the other as serial ports cannot be shared ie shut down one version before trying to use the other.

Have you tried a hard-reset of the chip (release reset when progress bar is on screen)?

Yes I tried a hardware reset during progress bar, same result. Gat me beat. I've tried it on 3 computers, a laptop and two desktops. Now it is time for bed.

 

[BeanieBots]

Add the line-

#COM 1

to the top of your code.
What is the EXACT error message you get when this line is added and you try a new download?

 

[Andrew Cowan]

Add that line to both programming editor versions - not just the one that doesn't work.

A

 

[BeanieBots]

Nice idea Andrew, except PE4.1.9 would just return a syntax error.

 

[VK5OQ]

To summarise:
Destination circuit is a prototyp board used to program over 150 28X's
Using a new 28X in the board and v4.1.9 of PE the 28X is loaded no problems. Firmware version 7.8. Repeat with a 2nd 28X, same result. Close v4.1.9
Run v5.2.6. Same program won't load into 28X. Error msg: "Error: Hardware not found on COM1".
All options OK, 28X, 16 MHz (xtal), 256 gosubs, Com1. Clicking Options-Serial Port-Test, I can toggle the voltage on pin 6 (Serial In) of the 28X between -.56V and 10.58V.

Computer is an AMD Sempron 1.8Ghz desktop and I'm using the serial port.

 

[inglewoodpete]

Did you really mean "-.56V and 10.58V"?

-.56V I can handle. Its the voltage across the PICAXE's internal protection diode.

10.58 volts at the PICAXE is a worry. PICAXE input pins can only cope with Vcc + 0.6v Are you sure that you're reading 10.58v at the PICAXE pin and not the junction of 22k/10k programming circuit?

 

[VK5OQ]

I'm not sure what is happening here but the voltage from the serial port when high, at the junction of the 10k and 22k R's is 10.83. On the other side of the 22k series R, ie directly on the Picaxe pin it is 10.60. The implication is that there is about 10uA flowing into the pin.

 

[hippy]

at the junction of the 10k and 22k R's is 10.83. On the other side of the 22k series R, ie directly on the Picaxe pin it is 10.60.

The reading at the 10K/22K junction is to be expected, but the reading on the PICAXE pin is not. The internal PICAXE diodes should have clamped the voltage to near +V and the 22K resistor prevents any damage in the course of that.

I would suspect that you either do not have a 22K fitted, you are using an input pin which does not have an internal diode fitted, an internal diode has 'expired' and gone open circuit, a strong enough power supply is not being used to hold the supply voltage at its own level.

On the 28X I am not aware of any digital input which does not have an internal diode fitted which would suggest one of the other causes.

With the same hardware configuration, same download cable, I am at a complete loss to understand how you would see different results with one version of the Programming Editor and another.

Added: What are the measurements on the pin when using 4.1.9 ?

 

[MartinM57]

...surely a ""Error: Hardware not found on COM1" error is the PC saying it can't talk to anything on COM1 at the operating system level, irrespective of what you might have plugged into it?

 

[VK5OQ]

4.1.9 doesn't have the serial port test facility. There is a program in the Picaxe loaded using 4.1.9 and this program is halted when the serial input pin is pulled high to 10 volts.
I can't spend any more time on this now. We are going on holiday for a week.

 

[hippy]

With 4.1.9 you can hold the 28X in reset while powered up and initiate a Firmware Check or a Hardware Memory clear or Program Download and you should see the Serial Input go high for a few seconds. That should be long enough to get a ball-park voltage reading.

Reading 5V5 on any PICAXE pin indicates something bad is happening, the hardware may be damaged or is being damaged. While the differing behaviour of two versions of Programming Editor is inexplicable, if there is something wrong with the hardware this could lead to unreliable programming or early failure in the field. Not the best situation if PICAXE are being provided for others to use ( which may be the case here ). I suggest you continue your investigations to get to the bottom of what is going on after your holiday. Hope you manage to have a good one.

 

[BeanieBots]

Another possible explanation for seeing such a high voltage on the serin pin is a disconnect on the PICAXE 0v pin.
Depending on the other IO loads, a PICAXE could actually run without it's 0v connected obscuring the real problem.

Either way, there is a hardware problem here.
I'm quite sure the PE version is a "red herring".

 

[VK5OQ]

Back from holiday, skiing in Victoria. Problem is solved, thanks to my good friend Jim who tried to program a PICaxe 28X with PE v5.2.6 He also found it didn't work. Conclusion is that there is an undocumented feature with this version that doesn't allow it to work with the 28X (firmware version 7.8). Jim sent me version 5.1.3 and this version programmed the 28X immediately using the same hardware as before. Incidentally Jim is responsible for the sale of 100's Picaxe 28X's.
The situation with the serial input pin of the Picaxe going to 10 volts is as expected. When I looked at the datasheet of the parent Pic of the 28X (Pic16F873) I saw that the serial input pin has diode protection only to ground not to +5. The Pic is quite happy for this pin to rise to +10V.
My comment about current flow into the PIc port was a red herring as the voltage drop I noted was caused by current drawn by the el cheapo DMM as the meter only has in input resistance of 1 Mohm.

 

[hippy]

The situation with the serial input pin of the Picaxe going to 10 volts is as expected. When I looked at the datasheet of the parent Pic of the 28X (Pic16F873) I saw that the serial input pin has diode protection only to ground not to +5.

You're right ( 28X=16F873A, 40X=16F874A ), Serial In, RA4 doesn't have a high-side diode clamp. I don't think anyone ever noticed that before.

The Pic is quite happy for this pin to rise to +10V.

I wouldn't venture "quite happy", but I've never heard there to be any problem with the 28X's or 40X's with respect to Serial In or problems downloading.

I've found a 28X Firmware 7.6 and can confirm 5.2.6 does not recognise it ( Hardware not found on COMx ). I don't have an earlier Programming Editor to test with at present. The PICAXE is responding correctly to download initiation so this is something we will investigate. It's not intended behaviour.

Is there a C:\Program Files\Programming Editor\Compiler\Picaxe28x.exe file ? If so, copy that somewhere safe. Install 5.2.6, copy the Picaxe28x.exe back into the directory ( over the 5.2.6 version ). That may work but no promises. Uninstall and go back to 5.1.3 if it doesn't.