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Join Date: Nov 2013
Location: West Newton,MA
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The TA does report a status byte to the DME but it seems to be the 'decision' of the TA to disable its motor drive bridge. The DME maps the byte value to an error code.
That said, I am wondering if I caused it. The way I control it at the moment is by programming 0%, 10%, 20%, ... 100% steps. These settings are associated with the number keys on my keyboard. To keep it programmatically simple. I am not ramping up and down between the values when I 'play my TA piano'. Since I am very abruptly changing the opening values from one to the other, I am wondering if I introduce a lot of settling error given that I have worn gears in my setup. Could in be tripping it over a certain (integration) value leading the fault logic to trip for safety reasons? I will have to experiment by adding ramping to my code. Easy enuf.
Beyond that I am wondering if I can kick the TA through some kind of re-initialization command. In my data logging efforts I did not find evidence of such a re-initialization. But I logged on 2 freshly replaced TAs pressing the gas pedal. I should have logged a ISTA/D TA test session. I bet it does this cal if it exists. Or in DIS which has a TA initialization command, supposedly.
Another thing I noticed is that the processor on the TA has a UART (TTL level serial port). I sniffed it with my scope. It pulses once when the processor comes out of reset. But it does not 'talk' characters. The pins are left unconnected. However, sometimes you have to wake these ports up by sending a return character or the like in first. I will do that later this week. Need to dig up my USB to 5V UART TTL converter cable. Sprechen Sie Deutscher ASCII?
Last edited by rt7085; 17th August 2016 at 05:53 AM.