oh yeeeaaahhhh...
finally, i've passed the exam.
thanks to pebe & nigel, eventhough i still don't understand how to connect tlp/rlp module.
'but i still want to know why it doesn't work
pebe & nigel, have you already know that from PC i'd used IC MAX232 to covert 232 level from PC, to TTL level from microcontroller.
'cos my friend told me, that my TLP/RLP module doesn't work it's not because like what both you've said (manchester coding).
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pebe asked:
What is the steady state voltage on pin1 of the TLP and RLP units, - ie. with no data being sent from the com port? ---- i don't know (i used 5V DC power supply for TLP & RLP)
When com port is sending, is data present at your micro? --- yes when i'm using cable (PC-IC MAX232-microcontroller)
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i want to tell you something,
when i used configuration like this :[microcontroller-TLP ~~~~ RLP-microcontroller], they (TLP/RLP) connect.
from osciloscop i saw 'image' data sent is the same as 'image' data receive.
next, when i used configuration like this :
[PC-IC MAX232-TLP ~~~~ RLP-microcontroller], they don't connect
from osciloscop i saw 'image' data sent is NOT the same as 'image' data receive.
it's only 2 or 3 bit of the beginning is the same, the others is 'high' (from TLP)
so.....