Pm sent thaniel Got it. I'll drop you an email 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 overfl...

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 ...

Thaniel, I use a SMA diode, has given me no problems at all. My setup consists of a 8v reg, transistors and resistors. Similar to that of the ELM design, but transistor at read line also, instead of using a voltage divider for circuit protection against high voltage. So long as 1x is stable and rel...

Just looking at your post, you seem to be searching for an electrical solution but havnt mentioned evaluation of the allpro or elm electrionics. There are also voltage tolerances in the official J1850 spec. Most devices dont follow the spec 100% and just generate a square wave, rather than the slop...

Wow. Lot added to this post since I've been here last. Well I feel like I've spent a couple months reinventing the wheel. But at least I learned a lot. I need a few components to validate the 4x mode works reliably. With the components I have it works but not 100%. Once I get the new parts I'll test...

Great thread guys. I agree the elm isn't ideal for a lot of this type of thing. I used so a bit then gave up on it a few years back when I needed a VPW transceiver. Ended up making our own (my son and I) out of a arduino mini. Similar to the designs shown earlier in this thread. I think it could do ...

Great info guy's thanks. I use a non ELM interface and used this info to write a little script to find the seed key. It's running now. Will see how many hours it takes