EB006 Rev7 USB power needed to run program?

[orion674]

Hello, I recently purchased a EB006 rev7, having upgraded from an "original" EB006 rev1.
If I use the EB006(rev7)and connect a LCD module EB005 (early ver1 +5v) and using a 13.5v external supply to the EB006 (rev7) the LCD display flashes on/off as does an external LED. The program does not execute as planned.
However if I also connect the USB port to a powered PC the flashing stops and the program operates as planned.
If I transfer the PIC16F628 and LCD and all wires/plugs to the original EB006 rev1. The program works without the USB connection.
I am using RB0 - RB5 for LCD and RA0- RA1as output RA3-RA4 as input. Disconnecting RA0-RA4 has no effect on the flashing.
Perhaps the LVP is somehow set? The config. file states it is disabled. I am using PPP V 3.10.14.28 to programme PIC's.


Incidentally the voltage on the screw terminal on the EB006(rev7) marked +14v is +12.05v.Would appreciate knowing the expected voltage.

Advise would be appreciated on solving this problem.

Many thanks in anticipation

[Benj]

Hello

Do you want to attach your program to the forum and I will give it a go here on one of our EB006 V7 devices to see if I can replicate your problem.

The voltage at the 14V screw terminal is essentially your input voltage minus approx 0.7V which is taken by the bridge rectifier.

If the chip configuration has LVP disabled then this should not be causing you any problems. Just out of interest if you move the USB/IDC2 jumper to the IDC2 position then does your program run as expected with the USB disconnected?

[orion674]

Hello Ben,
Many thanks for quick reply.

I changed the USB/IDC2 jumper to the IDC2 position. This has solved the problem.

Have I missed something in the EB006 rev7. documentation.

However when I tried to auto-detect. PP3 could not identify the chip

I moved jumpers back to USB and still could not identify chip. I inserted a different chip and had same problem.

I do not know why but after switching off all power and disconnecting USB and waiting approx. 2 minutes I can now identify chip and programme.

Please find .hex file attached.

Would appreciate your advise on how to proceed with jumpers in in future.

Regards Charles

[ste5442]

I have had the same issue - i cannot ID the chip unless I remove power (ie. unplug its USB connection) from the USB232 E-Block. This is extremely annoying and also an intermittent problem.
I think that when the USB232 e-block is powered it will be asserting some of its IO pins (possibly RTS) - this could effectively back-power some part of the chip causing a potential problem with 'resets'?

If you have a fix which means I can keep everything connected and prevents me from swapping cables each time I need to program the PIC it would be very much appreciated!!

[Benj]

Hello

Ok I just tested this using a EB006 v7, an 16F88 and a USB232 board connected to PortB, jumpers A and 1. Both the USB232 and the EB006 have a USB cable going to the PC. I have tested PPP and it is autodetecting the device correctly.

Is this similar to your setup? Does the autodetection work if you simply have both cables connected but have not connected hyperterminal etc.

[orion674]

Hello Ben

I have gone back to basics with this problem.
I programmed the supplied EB006 Rev7 board PIC16F88 with the follower programme RC-LVP.hex as suggested in the EB006 Rev7 documentation. With 13.5v supplied and USB connected to a working PC the follower works as I expected. I had previously run this programme upon receipt of the Board. However when I removed the USB connection the LEDs are lit in a "chaotic" manner. Frequently after the D2 LED is lit the D0 LED then lights and the follower resumes the normal sequence or repeats D2 lit then D0.
I have attempted to attached two bitmap files however I find Forum cannot receive bmp files. The 2 bitmap images show 'scope pulses on DO(RB0). The image "PIC16F88 13.5v no USB voltage.bmp" indicates the "hiccup" pulse. The image "PIC16F88 13.5v + USB voltage.bmp" shows a steady pulse train.

I have repeated the test with a different 16F88 with similar results to the above, I have also moved the same 16F88's, LED board to my original EB006 Rev1 board and the follower works as expected with or without the USB being connected to a working PC.

The images are derived from a PicoScope. If you wish to see the traces I would welcome advice on how to send. Easy options are psdata, CSV, txt, GIF, PNG, Matlab 4. I could of course convert the bmp to another acceptable graphics format.

Is the problem likely to be due to a faulty board or some other cause.

Regards Charles

[benp]

I have the same problem with EB006 rev7.
My program work properly with USB connected, power connected and J29 on PSU
It is still OK with J29 on USB and no power.
It does not work with USB not connected, power connected and J29 on PSU.
It is OK with a HP488-3

Can you reproduce the problem?
I tried to add capacitor between gnd and +14v or gnd and +5v with no results.
I tried with other power suplly with no results too.

Is this problem solved? Is it it a faultly board?

[medelec35]

I have attempted to attached two bitmap files however I find Forum cannot receive bmp files.

If you have windows xp or Vista the Paint program will convert bitmap to jpeg.
If you do a screen shot, you can then open paint, then save as jpeg.
Alternatively a great freeware package that will not only save as jpeg, but will reduce picture size, crop and tons of other features is called FSViewer see:
http://www.faststone.org/FSViewerDetail.htm
Alternately if want to send them to my email address I will convert them to jpeg and post them. Just PM me for my address if you are interested.

It might not be related, but when I had a problem with my programmer, it turned out to be jumper connections. just moving jumper up slightly cured problem.

[benp]

Is the problem solve (usb power needed to run program).
I want to buy 5xEB006 for autonomous robots with my sudents. Is there a working solution without usb.

Thank you

[Steve]

We have seen a few issues with jumpers on the EB006 board, especially the PSU/USB and the ICD2/USB link blocks. We are following this issue up with our manufacturers.

You can try putting these upside-down or replacing them.

For autonomous robots, ECIO might be a worth looking at.

[medelec35]

For my two pence worth, I had one of these EB0006 V7 board with the jumper issue, after moving jumper slightly, not had any problems with board at all!
I am very pleased with it and is defiantly worth investing in.
With jumper on PSU. I was running a program with LCD with USB and PSU connected, then disconnected USB and program was still running with no glitches at all.

[benp]

I performed more tests to analyse my problem:
The EB023 can initialize in flowcode with the USB connected and cannot initialize if USB not connected.
The others components are working properly.

Here is a file which show the problem

test initialize.fcf

(6 KiB) Downloaded 398 times

The config is:
16F887
14V power supply
j29=PSU
j12/13/14=USB
EB023 on port C (ethernet)
adress A8=A9=A10=0
Patch A
Ethernet connected
EB004 on port D (LED)

If you connect USB, LEDs D0 and D1 are on at the end (initialization OK).
If you do not connect USB, all LED are ON at the end (no initialization).

The problem occurs only with the EB023 ethernet board.
I try to test with 2 eb006, 2 eb023 and pic 16f887 and 18f2680, the problem is always the same.
I Tried different power supply and still the same problem.

I don't know if there is a link with this problem:
http://www.matrixmultimedia.com/mmforum ... 023#p11368

[Benj]

Hello Ben,

Thanks for the bug spot I will look into this and see if I can replicate the problem here.

[Benj]

Hello,

Yes I have been able to replicate the problem. The 18F4455 device on the EB006 is connected through to most of the pins of the target microcontroller to allow for a potential future scope application. However when the board is disconnected from the USB the 18F4455 is no longer powered. In some cases this allows a small amount of current to go through the 18F4455 input pins which can lead to problems like you are currently experiencing.

If you need to remove this problem from your board then you can connect a wire from the USB to the internal 5V supply which will mean that the USB chip is always powered. If you wish to do this then use a wire from the +V screw terminal on the EB006 and solder the other end of this to the USB pin shown in the picture below. I have tested this setup and your program is now working correctly with the USB disconnected.

EB006.jpg (17.72 KiB) Viewed 14432 times

Before plugging the USB cable back in I would disconnect the wire from the +V terminal to allow you to reprogram the device correctly and so the 5V regulator is not overstressed.

[benp]

Hello,

Thank you for your quick answer.
This solution is not very usable with students because they could forgot to remove the connection.
Is it possible to find a solution where the 18f4455 is powered with the j29 config jumper. I mean cut the direct connection to the usb and connect to the +5V from the config jumper.
Another question: will the board still be under garantee with this modification.

Thank you

Regards

[Benj]

Hello Ben,

I thought you may be needing this mod to allow you to embed the EB006 into an application and leave it there.

However as students are going to be using the boards I would not recommend the mod I suggested, you are also correct the board would no longer be covered under our warranty.

Its a tricky one because the 18F4455 is connected directly to the USB power and permanently shorting the internal 5V with the USB power means that programming will not work correctly.

Can you simply ensure that the USB cables are always connected when working with the students or is this not a possibility?

Another alternative for a permanent mod is to simply remove resistors R31, R34 and R35 from the board but this will break any future scope functionality on pins RC0, RC3 or RC4. As long as you do not damage the PCBs when doing this im sure we can still allow the boards to be under the normal warranty. Eg if you ever have to return them to us then please include a cover note stating the mods that have been made. [EDIT- NO, see below!]

This is the first time I have seen this setup on the EB006 causing a problem so It looks like it is only the EB023 that will cause any problems with the USB cable disconnected.

[Steve]

Just before anyone starts taking a soldering iron to their EB006 boards, I'd just like to point out that we would not be able to replace modified boards under our warranty scheme unless specifically cleared with us in advance.

The only workarounds I would advocate to this problem at this present time are:

1. Permanently connect the EB006 to the PC via a USB cable.
2. Create a custom cable that connects the +5V and 0V lines out from the terminal block to the appropriate ends of a USB cable that gets plugged in the the USB socket ont he EB006

Again, just to be clear - DO NOT MODIFY THE ELECTRONICS OF THE EB006 BOARD!

[benp]

I will use the USB cable solution.
Will this problem be solved in the next EB006 version (with for example a jumper to power or not the 18f4455)?