Well sorry for slow reply. Other projects and family life keep me busy. Did try the Schotky diodes and also built the listener circuit of the all pro and another send circuit using a comparator of our own design. Not enough time to build all the circuits yet. But have learned quite a bit about what is going on. Which I find interesting but doubt many here will. So won't clutter up this thread. Long story short is that my issue reading before changing diodes appears to have more to do with the ECU expecting certain times between certain message responses. And since the data was coming out 4x faster my program was responding sooner than expected. Or in other words it was reading my messages but it just didn't like when I sent them. The 1N4002 and the BAT46 diodes functioned good enough to work at 4x mode. let's see what else.
Oh we updated our code to get the VPW CRC on the very long messages to work. And nailed down the data CRC formula. Need to do some more testing on that But the data CRC appears to be a "Checksum-16 = Sum_of_all_bytes(file) mod 2^16". So a very simple formula.
cjcalhoun85 wrote:Would a blocking diode arrangement with pull ups on the mega work? I have a ds1054z oscilloscope and a mega with components. I also have a bench harness, 2 spare 1mb pcm's and hptuners. I am currently using the blocking diode arrangement for the crank and cam sensor inputs from a ls to a Arduino mega and it works great for that. I have visual studio on my laptop also. I am pretty much lost at coding but if I could be any help with testing anything just let me know.
Lots of different circuits would work. At least as long as the program being used is setup for the circuit it has. If you want to play with ardunio stuff drop me an e-mail (think there is a way to do that through this forum).
Im glad you got the 16 bit sum sorted. I believe 160baud passed on the link after I released that part of my work so you were able to adapt it for the arduino. Your welcome. You dont need the mod 2^16 if you just use a 16 bit variable and let it overflow. That part of the filter is the nature of the size of the storage, rather than part of the function explicitly.
antus wrote:Im glad you got the 16 bit sum sorted. I believe 160baud passed on the link after I released that part of my work so you were able to adapt it for the arduino. Your welcome. You dont need the mod 2^16 if you just use a 16 bit variable and let it overflow. That part of the filter is the nature of the size of the storage, rather than part of the function explicitly.
Thanks for sharing. But no we didn't extract the checksum calculation from the 300 lines of code you posted. You may have guessed this since we posted the checksum formula with the modulus function. Letting it overflow is interesting to know.
Finding that checksum was like number 30 on the to do list. But one day when looking at a bin read in a hex editor my son noticed a menu selection for "calculate checksum". After picking through a few choices one matched. Looked up the formula for that style checksum and voila.
Oh, ok thats cool. 160baud asked on your behalf and I gave him the snippet and explained it believing he was passing it back to you (as well as describing it a few times in this thread on earlier pages). Im actually glad that you and your son figured it out independently, you can learn so much more on the same journey that way.
I'm working on building a bench setup so that I can have most of the engine sensors so I can test tuning changes in a controlled environment. I modified my JimStim to output the low resolution 3 tooth crank trigger and 50/50 cam wheel that runs on my 4.3L truck. My truck runs a P59 PCM, but the OS is specific to the V6 so there isn't a ton of information available.
I'd be interested in doing testing once you guys get a cable to flash that is less than $100 because I've already spent too much on this hobby as it is.
LS1 Boost OS V3 Here. For feature suggestions post in here Development Thread. Support future development ->Patreon.
The odbdiag.net allpro http://www.obddiag.net/allpro.html is working at 4x with 128 byte packets now, which is sufficient. The USB variant is recmmended. Alex (obddiag.net) has said he will accept a merge. Ive got a different RX led pin configured in my branch because ive got an older hardware board. Im also not sure of the upper packet size limit and want to make sure that is sain before sending the merge request. If you want to try it, see https://github.com/antuspcm/allpro/tree/4xj1850 . The code should end up in master soon, then all allpros should have the support needed out of the box.
The app is looking decent too. The AVT support is behind, and the J2534 doesnt have 4x, but the foundations are starting to look pretty solid.
bubba2533 wrote:I'd be interested in doing testing once you guys get a cable to flash that is less than $100 because I've already spent too much on this hobby as it is.
In theory, both the USB and Bluetooth Allpro adapters should work. In practice, Bluetooth makes me kinda nervous... I bought one of each, but I plan to use the USB version for flashing and the Bluetooth version for logging.
I think it makes sense to order now, just in case the Allpro guy gets overwhelmed with orders when the app gets released.
Please don't PM me with technical questions - start a thread instead, and send me a link to it. That way I can answer in public, and help other people who have the same question. Thanks!