Error: Hardware not found on COM18!

#1
A couple of days ago I assembled a custom board containing a PICAXE-14M2. I get the subject error message every time that I attempt to download my PICAXE Basic program to it. I am using an AXE027 PICAXE USB Download cable plugged into a Stereo PICAXE socket installed on the board. I traced the circuitry from the stereo PICAXE socket to the 14M2 and can find no errors. This was done with continuity checks. I even re-seated the socket. I have verified that there is +5V between pins 14 and 1.

I continue to get the same response. COM18 is the correct port.

Does anyone have any idea what the problem might be?

Her is a picture of the board:

Antenna Controller.jpg
 
#2
Hi,

I would try to download a program in an other board, to be sure the cable is correctly working. Are you always using the same USB port?
I encountered the case where, for an unknown reason, the cable was not working any more ; the driver has to be reinstalled.
 

lbenson

Senior Member
#3
I assume you have the proper jumper or switch setting on S1? If so, does a loopback work? With nothing plugged into the board except the AXE027 cable, if you short pins 2 and 13 on the 14-pin socket and start a terminal program on the PC (e.g., puTTY or the PE terminal), when you type on the keyboard, do you see what you type?
 

hippy

Technical Support
Staff member
#4
It may be that the PICAXE simply requires a Hard Reset.

Another thing you can try is to program your 14M2 on another board or breadboard to output a continuous SERTXD message, then see if you can see that message using the Terminal when it is fitted to this board.

PICAXE chips coming off the production line have a "Welcome" message like that programmed into them so it is worth firing up the Terminal to see if anything is appearing.
 
#5
Technoman:
I don't have another board to download to. I verified that the AXE027 cable is functioning properly using the PICAXE Editor Settings > COM Port > Configure and test option. Select Test Download Cable from the menu that appears.

Yes, I always use the same COM port.

lbenson:
Yes, I have the proper jumper installed. Performing a loop back test as you suggest is a great idea, since it will determine whether or not there is a problem in the serial I/O circuitry. I just performed this loop back test. It worked fine.

Note: You can use the PICAXE Editor Settings > COM Port > Configure and test option for the loop back. Select Test Download Cable. Instead of unplugging the AXE027 cable and shorting the ring and sleeve together as instructed, install a jumper between pins 2 and 13 and continue. Skip the voltage test.

hippy:
There is no reset pin on the PICAXE 14M2. Power cycling has no effect.

As I mentioned above, I don't have another board.

I tried connecting with Hyperterminal and power cycling to see if the "Welcome" message appears. There was no response.

All:
It appears that I have a defective PICAXE-14M2.
 

hippy

Technical Support
Staff member
#6
It appears that I have a defective PICAXE-14M2
That could be a first if that is the case. I can't see anything wrong with your circuit board but it's possibly something very simple. Just a question of finding out what.

The usual approach with DIY hardware would be substitution; programming on another board, swapping with another known working 14M2, seeing if that 14M2 works with the other board. With only limited options it will be more difficult.

Can you post reasonably large resolution photos of both sides of your board ?
 

rq3

Senior Member
#7
Assuming that your PCB photo is a top side view, everything looks fine. But, there are two things that caught my attention.

The pinout for the 1/8 inch stereo jack that the Axe027 cable plugs into varies between manufacturers. Verify that yours is correct.

Also, your R2 should be 10K ohms, and R1 should be 22K ohms. Make sure they are not swapped in value. If they are, the loop back test might work, but the chip may not accept a program.

If this all checks out, hippy was not referring to a reset pin, he was referring to a hard reset, applicable to all Picaxe chips:

1) Make sure the Picaxe has no power
2) Hit the "Program" button in the programming editor
3) When the editor shows that it is attempting to connect, apply power to the Picaxe
 
#8
If your PICAXE is new and has never been programmed by you before, it should constantly output a message (like) "I am you PICAXE 14M2" on the SerOut pin, when the chip is powered up. You can check this by connecting an LED with ~330ohm resistor between the PIN and 0v. The LED should flicker every one or two seconds as the message is transmitted.

In my experience, PICAXE chips are pretty tough little beasts and can survive a lot of mistreatment. However, they do not survive being connected to voltages much over 6v on any pin (I'm not suggesting that this has happened in your case).
 
Last edited:
#10
Thanks all!

RQ3:

I followed your procedure (which is in the help section) and successfully programmed my 14M2.

Here is what appeared in the Workplace Explorer Compiler window:
____________________________________________
|Compiled successfully. |
|Memory used = 151 out of 2048 bytes. |
| |
|Connect power now! |
|Searching for hardware on COM18. |
|Downloading program. |
|................ |
|Downloading data. |
|.................. |
| |
|PASS - programmed PICAXE-14M2 v6.A |
|___________________________________________|

It puzzles my why you get the subject message when you select "Download" before the program has been downloaded or select "Check PICAXE type connected". Now that the chip has been "Programmed", there is no response when I select "Download".

Oh well, I guess that it is time to move the jumper and try the program.
 
#11
If your PICAXE is new and has never been programmed by you before, it should constantly output a message (like) "I am you PICAXE 14M2" on the SerOut pin, when the chip is powered up. You can check this by connecting an LED with ~330ohm resistor between the PIN and 0v. The LED should flicker every one or two seconds as the message is transmitted.

In my experience, PICAXE chips are pretty tough little beasts and can survive a lot of mistreatment. However, they do not survive being connected to voltages much over 6v on any pin (I'm not suggesting that this has happened in your case).
I just ordered a couple more 14M2s. In thinking about voltages over 6v applied to any pin, I think that I may have applied higher than 6v to outputs B1, B2, B3, B4 and B5. B0 was saved because it as connected to the serial port. In checking the outputs, all appear to be floating except B0, which is a solid zero volts.

Here is what happened:

The chip on the left is supposed to be a TBD62781APG. I ordered a TBD62783APG by mistake and installed it. The problem is that the power supply pins are reversed. All of the internal diodes conduct if the polarity is reversed. This may have resulted in application of up to +12v to the attached inputs, up until the time that a 2N3906 switch in series with the 12v supply failed.

The TBD62781APG is an array of eight DMOS Transistor Gate Drivers. I use six to apply 12v to one of six relays and a parallel LED, 1K resistor combo for indication of the selected relay.
 
#12
That could be a first if that is the case. I can't see anything wrong with your circuit board but it's possibly something very simple. Just a question of finding out what.

The usual approach with DIY hardware would be substitution; programming on another board, swapping with another known working 14M2, seeing if that 14M2 works with the other board. With only limited options it will be more difficult.

Can you post reasonably large resolution photos of both sides of your board ?
The best photos that I was able to take are attached. The bottom photo is the board flipped around the horizontal axis. Please forgive the crud on the bottom. It's adhesive residue from the two sided foam tape that I use to secure the board in place.
 

Attachments

#13
...The TBD62781APG is an array of eight DMOS Transistor Gate Drivers. I use six to apply 12v to one of six relays and a parallel LED, 1K resistor combo for indication of the selected relay.
I installed a TBD62781APG and tested it by applying 5v to each of its input pins. Much to my surprise, multiple relays and LEDs lit. I had the PICAXW-14M2 plugged in at the time. I removed the 14M2 and only one relay and LED lit up at a time, indicating that multiple 14M2 outputs were shorted. My replacement 14M2s will arrive in a few days.
 
#15
There definitely is no wiring fault. I performed extensive continuity checks to verfify that. The 14M2 was installed properly.

I should clarify what I mean by shorted. The outputs were shorted together, not to ground. 5v was applied to multiple TBD62781APG inputs via the shorts.
 

hippy

Technical Support
Staff member
#16
That doesn't seem so likely as either a wiring fault or all 14M2s pins programmed to be on...
Hard to tell. The incorrectly fitted TBD62783APG has diode clamps which would put 12V straight to PICAXE outputs which could have some pretty impressive effects. The clamping diodes on the PICAXE pins to 5V could simply have melted and shorted to 5V.
 
#17
Guys! I finally received my new 14M2's. Here is what I have observed so far:

inglewoodpete: "If your PICAXE is new and has never been programmed by you before, it should constantly output a message (like) "I am you PICAXE 14M2" on the SerOut pin, when the chip is powered up."

Here is what it outputs:

1544132657228.png

Note that there are no printable characters.

jehill39: "It puzzles my why you get the subject message when you select "Download" before the program has been downloaded or select "Check PICAXE type connected". Now that the chip has been "Programmed", there is no response when I select "Download"."

Nothing happens when I click "Download" before the program has been downloaded now. I get the following message when I select "Check PICAXE type connected" now:

PICAXE-14M2 Compiler
Version 3.4
Copyright (c) 1996-2016
Revolution Education Ltd

Searching for hardware on COM18.

PASS - firmware PICAXE-14M2 v6.

RQ3: The response to your hard reset procedure is below.

Copyright (c) 2011-2015
Revolution Education Ltd

Preprocessing files...
C:\Users\johne\Documents\PICAXE Editor\Documents\ya2cp1h2.bas

PASS, preprocessing successful.

PICAXE-14M2 Compiler
Version 3.4
Copyright (c) 1996-2016
Revolution Education Ltd

Compiled successfully.
Memory used = 151 out of 2048 bytes.

Connect power now!
Searching for hardware on COM18.
Downloading program.
.................
Downloading data.
..................

PASS - programmed PICAXE-14M2 v6.A

Now that I have successfully programmed a new 14M2, it's time for software testing!
 
#18
Congratulations on success with programming your picaxe 14M2.

The garbage on your Serial Terminal display is because the baud rate is set at 9600. The default rate for the M2s is 4800. The expected text would probably have shown at that rate.
 
#19
I concur with lbenson. While you were getting gobbldegook on your terminal window, it appears to be repeating. If you change the serial port's speed to 4800 baud (for a 14M2 running at its default speed), you should see an intelligible message.
 
#20
It sounds like you're on your way. FWIW, the serial in and out, C.5 and B.0 locations, on the 14M2 socket appear to be bent in quite a bit like you stuffed a probe in them to do continuity checks. I reckon they could/will cause issues down the road if the matching legs on the 14M2 aren't bent inward enough to make good contact. If you start seeing programming issues, I'd replace that socket.
 
#21
ibenson: Thanks for that observation. I guess that when you program a 14M2 using the PICAXE Editor, it automatically selects 4800 baud, right?

Hemi345: That may have happened when I inserted a jumper to do a loop back test. The test probes on my multi-meter couldn't have done that.
 
#22
I guess that when you program a 14M2 using the PICAXE Editor, it automatically selects 4800 baud, right?
From the manual ...
Code:
Effect of Increased Clock Speed:
Increasing the clock speed increases the serial baud rate as shown below.
4MHz  8MHz  16MHz  32MHz  64MHz
4800  9600  19200  38400  76800
M2 chips operate by default at 4MHz, so the 14M2 - unless you change the frequency by using setfreq - will output at 4800 baud.
 
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