- Tue Aug 03, 2021 2:56 pm
#52264
I haven't seen any issues with the CH340 UARTs, and there are hundreds of them in Speeduinos, though a bad one is a rare possibility. I have not heard of specific HEI bypass issues in Speeduino either, and there are a number of them (and other types) running bypass fine, so there's hope that way.
I would 'scope the connected bypass line when low and high (crank and run), looking for clues. Could be a crippled module, poor connection, wire noise, etc. You don't have something sneaky going on, like non-resistor or damaged spark plugs or HV wires, or distributor phasing, no?
Alternatively, the cranking bypass on those modules is no longer necessary for most applications, as we have full control over cranking and run timing. If it were me and there were no other issues present, I'd skip the bypass feature and set the cranking and tables to work the same without it. The only side-effect is waiting for Speeduino to sync before it fires if Skip Cycles is set >0. Just an option.
Another alternative is the old relay method, in this example as adapted by MS. My version simply uses a 5-pin relay with the signal on terminal 87A (not 87), so the module receives bypass signal except when cranking (wired to hot-in-start instead). Rather than a wire all the way to VREF, 4k7 and 2k2 resistors make a safe 4 to 5V right at the relay. Whatever gets you where you're going in either the simplest or most acceptable way, in your judgment. There are many ways to do this. Do what makes you giggle.
I would 'scope the connected bypass line when low and high (crank and run), looking for clues. Could be a crippled module, poor connection, wire noise, etc. You don't have something sneaky going on, like non-resistor or damaged spark plugs or HV wires, or distributor phasing, no?
Alternatively, the cranking bypass on those modules is no longer necessary for most applications, as we have full control over cranking and run timing. If it were me and there were no other issues present, I'd skip the bypass feature and set the cranking and tables to work the same without it. The only side-effect is waiting for Speeduino to sync before it fires if Skip Cycles is set >0. Just an option.
Another alternative is the old relay method, in this example as adapted by MS. My version simply uses a 5-pin relay with the signal on terminal 87A (not 87), so the module receives bypass signal except when cranking (wired to hot-in-start instead). Rather than a wire all the way to VREF, 4k7 and 2k2 resistors make a safe 4 to 5V right at the relay. Whatever gets you where you're going in either the simplest or most acceptable way, in your judgment. There are many ways to do this. Do what makes you giggle.
-= If it was easy, everyone would do it =-
- By Tassuperkart