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Posted: Thu Mar 09, 2006 11:56 am
by Matt
power loss is just a guess. i dont know for sure what caused it in those particular cirsumstances. there is already a 100uf cap on your board for small interruptions
the new caps are for noise filtering and getting rid of over/under shoots on the TX/RX lines
anyway new software is online.
Posted: Fri Mar 10, 2006 4:02 pm
by Stinky
The new version is working well. I did two logs tonight and it seems the auto retry is doing it's job. Log is attached
Posted: Mon Mar 20, 2006 9:53 am
by Matt
i've got all the parts and have been trying out the caps last night. over and undershoot problems are gone but replaced with a spike in the midlde of transitions. i'm going to try some other values with the caps to smooth the signal out
Posted: Tue Apr 04, 2006 3:07 am
by Stinky
Any news on the caps? Anything I can add to my board to see if it helps?
Posted: Thu Apr 06, 2006 12:01 am
by Matt
i'm just about to get some new USB connector pcbs made up. what i will do for the three rev 1 boards yourself, bernard and charles have is use one of these with onboard caps and post those out to you
you will need to pull the glue off your existing usb connector and solder that and the cable onto the new pcb when it arrives.
i found some ringing in longer usb cables on the scope even with the capacitors. shorter cable should reduce this
i am running a 6 foot USB A-B cable also and didn't have the same level of problems you had with your cable. i think cable quality and shielding could be an issue.
the pocket romulator site also says your laptop must be shielded to vehicle chasis. i blew up my romulator CPU last week because of floating voltages or static... probably the first. they are sending another one out [$79USD repair fee but luckily since im a developer they are helping me out here]
didnt have any problems with disconnects over the last week while continously connected with the new boards. i used a jumper lead to short the ECU to chasis
you mention using a hub? usb 2 hubs and connections can cause problems with FDTI chips. 33nf caps are meant to solve this. i have the caps on the new board adaptors
hopefully problem gone soon. is about four weeks from now okay to send you an updated USB adpator PCB?
Posted: Thu Apr 06, 2006 3:40 am
by Stinky
Four weeks is no problem. Let me know if you'd like some $ for parts or post.
How would I go about shielding my laptop to the vehicle chassis?
I'm not using a USB hub at all. It goes straight into the laptop.
Do you think wrapping the cable in aluminum foil or something similar might make a difference?