PICAXE 28X1 - Hardware not found error

All,

My first post here...

I am quite new to PICAXE and had previously worked on few 8M projects. Recently I started on a project with 28X1. The project is unfinished and I was in the process of adding new functions to the main program. I have a breadboard where everything wired and what ever I have implemented so far is working fine.

2 days back I started getting the "hardware not found" error when trying to program or when I try to check. I had gone through everything:
- hard reset on picaxe
- re installed the usb drivers (i use the original cable)
- reset pin pulled up
- checked and rechecked the serial connection (3 pin socket and the 10k/22k)

Everything seems to be fine and the 28x1 is working with what ever I implemented so-far.
Its just that I am unable to write any more changes to the chip.

I replaced the 28x1 with a new one (I should have tried this before) and I am able to download the program without any problem.

So my question is:
- Has my old 28x1 reached its limit and gone corrupt ? if so should it still work with the what ever code i have in it ?
- Could it be just an issue with the Serial in /Serial out pins (Pin 6 and 7) of the old 28x1 ?
- Should I be checking anywhere else in my PC to sort the issue.

I now have the old 28x1 in a different board ready to be programmed again if I get any encouraging pointers from here.

Thanks for your help.
RG.

Perhaps I missed it but have you checked the power supply to the PICAXE?

Welcome to the PICAXE forum.

It is probably worth trying to program the old 28X1 on the different board to see if that makes any difference. It might just be a matter of Hard Reset timing as it can be a bit tricky to get that right; hold in reset or powered off, initiate the download, wait for "Connecting to ..." then release from reset or power-on.

It is possible the chip has become damaged but it would be quite unusual for that to just suddenly happen.

If the chip were 'worn out' it would more likely give download verification errors than hardware not found. The firmware itself is write-protected in the chip so it cannot be corrupted or erased under normal use. Despite performing repeated downloads to the same PICAXE chips during development and testing I have never managed to wear one out but it is potentially possible.

premelec said:

Perhaps I missed it but have you checked the power supply to the PICAXE?

Click to expand...

Yes, the power supply is fine.

hippy said:

Welcome to the PICAXE forum.

It is probably worth trying to program the old 28X1 on the different board to see if that makes any difference. It might just be a matter of Hard Reset timing as it can be a bit tricky to get that right; hold in reset or powered off, initiate the download, wait for "Connecting to ..." then release from reset or power-on.

It is possible the chip has become damaged but it would be quite unusual for that to just suddenly happen.

If the chip were 'worn out' it would more likely give download verification errors than hardware not found. The firmware itself is write-protected in the chip so it cannot be corrupted or erased under normal use. Despite performing repeated downloads to the same PICAXE chips during development and testing I have never managed to wear one out but it is potentially possible.

Click to expand...

Yes, before I throw it out, I will try on a different board.
I am still not convinced that the chip is damaged as it works as expected with the last code I downloaded. Will give it a try again tonight.

Thanks hippy for the suggestions.

RG.

Hard luck - I tried all options and I still have the error just for that one chip !

One thing I noticed is that, when I start the download, it says "Searching for COM..."Exceptiona and it throws the error. It doesn't get to the point where it says downloading. So I am not sure if the Hard Reset is making any difference or not.

Btw, this is all done on a new board and on a new PC. If I then connect to the new chip its all fine - no issues.

I guess I will keep the 28x1, just in case if there is a possible resolution I could try it out.

Thanks,
RG.

vu3hpf said:

One thing I noticed is that, when I start the download, it says "Searching for COM..."Exceptiona and it throws the error. It doesn't get to the point where it says downloading.

Click to expand...

That would be as expected; programming Editor cannot start downloading until it has found the hardware to download into, has verified the correct PICAXE type for the download is attached.

Hi, I might be on the wrong track here, but isnt the 'com port' separate from the picaxe?
Does the editor not find the port first.
Good luck
john

I'm 74 year old and new to picaxe stuff but; if you changed to a new computer and ust editing an old program shouldn't you also reset the com port in your programming software?

forgive me if I'm wrong!

Welcome to the PICAXE forum, xixray.

You are right about having to select the correct COM port when moving to a new PC but, given vu3hpf can download to a new chip but not the old one, it seems the COM port setting would be correct. Well worth double-checking that is the case though !

Thanks for the WELCOME Hippy!
Although it's my first post I must admit that I've learned a lot just by reading the problems and answers in this forum - keep up the good work!

So my question is:
- Has my old 28x1 reached its limit and gone corrupt ? if so should it still work with the what ever code i have in it ?
- Could it be just an issue with the Serial in /Serial out pins (Pin 6 and 7) of the old 28x1 ?
- Should I be checking anywhere else in my PC to sort the issue.

Click to expand...

1. Unless you have programmed this chip over 100,000 times it is not worn out.

2. Not sure what you mean by an issue with serin/ serout pins, bit it is possible that one of these pins is "blown".
A blown pin will many times act like an internal short. This will result in the Picaxe drawing 20ma to 50 ma
when power is applied. You can check this with your meter. When power is applied to the Picaxe, the current draw
through the V+ Pin should be about 4ma or less. If you do not know how to measure current with your meter just ask
and someone here will happily guide you.

3. Check the chip and make sure that one of the Pins is not bent over underneath the chip or broken off. This can be easy to miss.

4. You did not indicate what IDE you are using (PE5,PE6). PE5 has a graphical serial port test that toggles the serin pin high / low. For folks without a scope this is a good test to tell you if the download circuit is working correctly. Also, if the serin pin is internally shorted this test should indicate that. Suggest you run this test and provide the voltage results.

5. Make sure that the download circuit is correct. The only thing connected to the Picaxe serin pin should be one leg of the 22K resistor. The 10K goes on the other side of the 22K. The 22K is only there for current limiting when using a +12 / -12 RS232 levels and is not really necessary when using an AXE027. For a test only, I suggest you change the 22K to 1K and see what happens.

6. With the chip in the socket/ breadboard and power applied measure the voltage directly across Pins 19/20. What is it?
Measure the voltage directly across Pins 8 / 20. What is it ? Do these match the supply voltage ?

7. All indications suggest that you have a duff / blown chip, provided that you have done the hard reset correctly and that the chip has no bent under pins. Some of the steps above are to verify a bad chip by taking actual voltage / current measurements which is part of any good troubleshooting process.

Good luck