K8055 - DO8 LED permanently lit, no PC recognition

Hi,

I’ve had my K8055 since Xmas, and it has worked fine so far with the demo software.
However, recently, I wired up the board to control a 12V lamp via a reed relay. I connected an external 5V regulated PSU to the board (+ve to Clamp and -ve to Ground). I then conected my relay between the clamp and digital output 1 connections. I found this setup pictured in the instructions that came with the board.
When I plugged the board into my PCs USB port, the output LED 8 lit permanently, along with the power LED, and my PC reported an overload on the USB bus.
I disconnected everything, and tried just connecting the USB to check for damage, and I got two flashes from LED 8 then permanently on - power LED came on ok.
The PC can no longer see the K8055, but my USB port still works with other devices.

Can you tell me what I’ve done wrong here, and how I can resolve it?

Many thanks.

For some reason, you have probably connected an external souce in parallel with the K8055 +5V, which probably caused a current to flow into the K8055 +5V line. Most likely, the VK8055 chip is defective. You can return it for verification and/or exchange. You can find the address in the manual.

According to your description your external wiring was OK.
Did the PC report an overload on the USB bus only when your additional circuitry was connected?
Based on the LD8 indication it seems that the PIC microcontroller IC3 is defective.
The first two flashes of the LD8 indicates that the PIC microcontroller software started properly. On the third flash the LD8 stays on if the USB connection is not initialized properly.

I put together the 8055 today, run the install and then found the demmo software on the disk and ran that, the demo software would not connect. The board flashes twice on LD8 and then stays on, no usb connectivity.

When I go the control pannel/systems/devices and look at this device it has USB K8055 It sais ‘no driver files are required or have been loaded’. It sais the device driver for this is not installed. Does it need one?

Its listed under other devices, It thinks its a Human Interface Device, under properties, trying to seach for this on you disk I carn’t find any.
it tries to look in c:\windows\INF\HIDDEV.INF and sais the hidclass.sys was not found.
I am running windows ME

Can you help me, if I should, where can I update the driver from on you disk? would this not be handaled by the setup/instaltion. There is no installtion notes or details that I can find. I have many other devices connecting Ok on the usb port, but not this type. (HID)

what should my next steps be please

Return your processor for verification/exchange to:

Velleman Projects Tech. Dept.
Legen Heirweg 33
9890 Gavere
Belgium

K8055 is a Human Interface Device and needs no drivers to be installed.
After plugging it to the PC there in Device Manager under Human Interface Devices you should see two entries called “HID-compliant device” and USB “Human Interface Device”.
Check that you have the files Hidclass.sys, Hidparse.sys and Hidusb.sys in the Windows\System32\drivers folder.
Instructions how to reinstall any missing files see:
support.microsoft.com/kb/315973

[quote=“VEL255”]Did the PC report an overload on the USB bus only when your additional circuitry was connected?
Based on the LD8 indication it seems that the PIC microcontroller IC3 is defective.[/quote]

Yes, the board worked perfectly before I tried my external circuit.

I can’t figure out why it should fail like that. I’ve tested my PSU and it’s giving out a nice steady 4.9V, and my relay works fine on its own. I’m pretty sure I didn’t accidentally short anything, but that’s about the only reason I can come up with.

[quote=“VEL417”]Return your processor for verification/exchange to:

Velleman Projects Tech. Dept.
Legen Heirweg 33
9890 Gavere
Belgium[/quote]

How much will it cost me for a return?

Thanks for your help so far.

Sorry, no exact princing available. In any case it will be less than a new kit.

Thanks for the pointer on installinging the hidclass.sys , it was in the system32 directory anyway, when I whent through and tried to reinstall it again, it asked for the ME system install disk, and wanted the BASE2.cab file to extract it from I managed to find it , I gues its reinstalled?? not sure why it could not find it. and now have a connection… thnaks

I just put together a brand new K8055 kit and when i connect i get same indication as mentioned here , 2 flashes of LED8 and then it stays lit. Power LED also lit. I have no connection to software and get fault message in Windows XP . I tested in 4 different computers (XP, win2000) and all same problem. I tried connect via a HUB, same again.

I checked all connections to IC as mentioned in other posts here but only strange i can find is low voltage between leg 9,10 in IC3 ( 0,25V) …

What to do ??

The microcontroller starts to run but it can’t create the USB connection to the PC.
Please check the voltage at pin 14 of IC3. Should be about 3V.

  • Check that C6 and R35 are right value and soldering OK.
  • Check that the connections from pins 15 (D-) and 16 (D+) are OK to the USB connector.
  • Check that no short circuit between the signals D+ and D- and no short circuit from the signals to +5V or to GND at the USB connector.
  • Check or change the USB cable.

If all these are OK then the microcontroller may be defective and you have to return it to Velleman for verification/exchange .

It seems like there is a connection in the circuit board between two poles for the USB connector, but it is in the coppersheet not because of my soldering. Is it possible to get a sketch or picture of that area so i can cut the poles correct ?

I managed to cut the pole free, it was the d+ that had connection to ground in the circuit board !! The stuff runs like a clock now !! Coool !! Just wanted to leave a hinch for others that might have same problems !! Check the circuit board !!

This is good news that you got the K8055 working!
The bad news is that the short was on the PCB.
This info may help other users to locate the short between the D+ and GND.

The place was where the USB connector is soldered to the PCB. Looking from under PCB there are 6 solderings for USB connector to PCB. 2 of them iare the big ones and the remaining 4 are D+ D- and 5v+ and 5v-. The problem i had was where D+ is soldered to the board. This connection should be purely connected to pin 16 on IC3 but PCB must be faulty fabricated since this point had a bridge to ground… which is very close to the soldering point. What i did was only to cut the bridge and all worked fine.