Intermittent Problem USB Cable

Kruskal · Post by **Kruskal** » Mon Mar 06, 2006 10:37 pm

Sometimes, when I try to upload/download from/to my 8811 using IR, I get the message:

SDA is being held low. Make sure batteries are installed in
remote.

Various combination of restarting IR and replugging the cable make the problem go away. I can't detect a pattern.

Anyone know what is happening? It wouldn't be so bad if I knew the sequence to fix it.

Thanks for any hints -- Vincent

Capn Trips · Post by **Capn Trips** » Tue Mar 07, 2006 5:28 am

Have you read this? It may not apply to USB cables, but is easy enough to try.

Kruskal · Post by **Kruskal** » Tue Mar 07, 2006 11:14 am

Capn Trips wrote:Have you read this? It may not apply to USB cables, but is easy enough to try.

OK, I'll try that next time. But removing one battery altogether might make it work??? Now THAT is bizarre!

Thanks -- Vincent

whompus · Post by **whompus** » Tue Mar 07, 2006 11:59 am

The pattern can be that the remote is not plugged in before launching ir. In most cases the usb driver needs to be initialized before launch of the program. The same as with most other usb devices that gets power from the usb port.

Mark Pierson · Post by **Mark Pierson** » Tue Mar 07, 2006 12:43 pm

whompus wrote:the remote is not plugged in... the usb driver needs to be initialized

The remote doesn't need to be connected to the interface for Windows to recognize it. Windows only looks for and sees the USB chip and doesn't care what's on the other side. On both PC's where I use my USB cable, Windows plays the "device detected" sound whenever I connect it.

Another thing to check is whether or not Windows has power-saving enabled on the USB ports. Sometimes if the port goes to "sleep" with the interface attached, Windows might not properly "wake" it. I had that problem on my old PC when I first built the USB cable from the original prototype design Joe Cutler did.

whompus · Post by **whompus** » Tue Mar 07, 2006 1:39 pm

Mark... I am sure you know more about this then I do in a big way.

Wouldn't that error be from the eeprom in the remote on initialization to the flashrom in the cable? Meaning the flashrom in the cable does not see the eeprom in the remote as buss free state. When the flashrom in the cable sees the eeprom in the remote wouldn't it need to be kind of in a reset state? In other words scl and sda held high. Or am I thinking of non powered devices?

Mark Pierson · Post by **Mark Pierson** » Tue Mar 07, 2006 3:48 pm

whompus wrote:Wouldn't that error be from the eeprom in the remote on initialization to the flashrom in the cable?

I don't think so, but also admit I'm just guessing here. As far as I know (from discussions I had with Tommy Tyler) the USB chip handles ALL communication with the PC. The PC (i.e. driver) doesn't know what's on the other side. I think the chip itself is causing the error, but don't know why. That being the case, IR is talking to the driver and never "sees" the EEPROM itself either.

Again, I'm guessing, but I did have the power problems on an old PC and had the same intermittent results from the interface.

mkmcgregor · Post by **mkmcgregor** » Tue Mar 07, 2006 5:44 pm

Have you checked or recently replaced the batteries. Just a thought, because my remote is doing weird things only with FRESH batteries; just put up a new post about it. The older batteries that I've been working with for a week work fine.

So, if you just changed the batteries out, it's possible that the same parallel interface failure I'm seeing is occurring with your USB interface intermitantly, since the problem is apparently in the remote side of things for me.

Just a thought. I doubt it's your problem, but it's something to check.

Kruskal · Post by **Kruskal** » Fri Mar 10, 2006 2:12 pm

whompus wrote:The pattern can be that the remote is not plugged in before launching ir. In most cases the usb driver needs to be initialized before launch of the program. The same as with most other usb devices that gets power from the usb port.

I've discovered that it is really important to have the remote connected to the cable BEFORE the cable is plugged into the PC.

When updating a number of remotes, it sometimes works when one remote is unplugged and the other attached and sometimes not. When it fails, unplugging and replugging the cable from the USB port needs to be happen. It may depend on how long the it took to switch remotes.

I also had an 8811 with a broken port so that it ALWAYS caused the SLA message. That interfered with my experiments somewhat.

Thank for all the help -- Vincent

Post by **ElizabethD** » Tue Mar 14, 2006 10:33 pm

Mark Pierson wrote:
whompus wrote:Wouldn't that error be from the eeprom in the remote on initialization to the flashrom in the cable?
I don't think so, but also admit I'm just guessing here. As far as I know (from discussions I had with Tommy Tyler) the USB chip handles ALL communication with the PC. The PC (i.e. driver) doesn't know what's on the other side. I think the chip itself is causing the error, but don't know why. That being the case, IR is talking to the driver and never "sees" the EEPROM itself either.

kruskal wrote:
whompus wrote:The pattern can be that the remote is not plugged in before launching ir. In most cases the usb driver needs to be initialized before launch of the program. The same as with most other usb devices that gets power from the usb port.
I've discovered that it is really important to have the remote connected to the cable BEFORE the cable is plugged into the PC.

It might go beyond the driver conversation.
Since this thread includes guesses, let me add some more. Based on XP, my experience so far has been that devices which are registered with the USB authority (??), and/or Bill Gates, get recognized nicely as you plug them in. Unregistered ones cause problems, which, usually, are resolved by connecting the device before the application starts. The worst case is when a not very bright

manufacturer who builds different USB devices (flash, harddrive, printer, lab instrument) registers them all under one number, totally confusing Windows

Disclaimer - I do not have jp1 USB cable. As I said, I'm just adding a guess. But considering that jp1 USB cables are most likely unofficial, my guess would be to plug it in before running IR. I do know I have to do that with an e-bay issue of a USB cable for my phone. And even then the application needs my confirmation as to whether it really is connected to such and such USB port. And for sure it doesn't like you to switch between several USB ports.

rickety · Post by **rickety** » Thu Mar 16, 2006 5:33 pm

I too have the same SDA low problem. I just received a USB interface from DIYGadget and have not been able to use it yet.

Kruskal · Post by **Kruskal** » Thu Mar 16, 2006 6:14 pm

rickety wrote:I too have the same SDA low problem. I just received a USB interface from DIYGadget and have not been able to use it yet.

Did you use this order:

1- Plug into remote
2- Plug into PC
3- Launch IR

Vincent

rickety · Post by **rickety** » Thu Mar 16, 2006 7:36 pm

Thanks Kruskal for the suggestions, but yes. However I have now resolved it. The connector needs to be put on the header the opposite way around than shown in DIYGadgets documentation.

I have also posted this info in another thread here, and on their feedback forum.

(I had two remotes that both behaved the same, so I was fairly sure it wasn't something unique to a particular remote)

JP1 Remotes

Intermittent Problem USB Cable

Intermittent Problem USB Cable

Batteries, fresh ones can kill the interface.

SDA Low with USB-JP1 --- Solved (for me anyway)