Nevilleh wrote:weber wrote: Hi Nevilleh.
Although it is clear now, thanks to 4Springs' measurements, that it is not a clock speed problem, you seem to have failed to understand both of the points I made in my previous message.
Is that an insult? Maybe I'm too sensitive. But I didn't fail to understand, I just didn't bother reading it.
It was certainly not intended as an insult. It might well have been my deficiency in explaining, or you might have been too busy to do more than skim it. It did cross my mind that perhaps you hadn't read it at all, but I gave you the benefit of the doubt on that. And I did say "you seem ...".
Your 10% spread (+-5%) does apply when you know that one of the parties to the async comms has essentially 0% error, e.g. a crystal controlled master unit. Perhaps that's what you were thinking of.
Anyway, I expect that other readers who might need to know this stuff, have got it by now. If not, draw yourselves some diagrams.
. I kept it there for 5km - cca 2 minutes. Current was cca 550A and voltage at 115VDC this means 2,75V/cell!!! Also means about 60kW on the motor maintaining the speed. I have no illusion, efficiency at that load is in 70%s though!
I discovered that somehow i muddled up the master pcb files when i sent them off to get made. So i seem to have an older version of the master board. Lacking the pullup resistors on the switches. Easily corrected. So after fixing those i fired up the maser module in isolation and got the expected display when not connected to cell modules. So then i loaded the two cell modules on cells. No sparks. 
However once they were connected up to the master module still no comms. So i built another master module to compare and got the exact same results. So whatever i did wrong i did it consistently wrong. 
