COM2Propeller problem

solarprism

Hi everyone, i'm new to this MCU.
I ve bought 3 Propeller MCUs and now make a programming cable.
I make one according to schema on Parallax website.
The first time i attached it to my PC and F7 it shows a messenger said that Propeller ver 1.....,but the next time i plug it in no MCU is recognized.
I used AP1117 to create 3,3V from 5V USB.
I have tested the serial communication by connecting Tx to RX and echo on unchecked but only Tx is blinking and no character on lower windows ( i do like in post #31 at http://forums.parallax.com/showthread.php?t=84805&page=2 )
when i use a multimeter to check the voltage on Tx and Rx i saw the Tx is approximately 3,1V and Rx is only 2,2V
Please give me some advice,thank you

solarprism

(T T) somebody help me

Dr_Acula

Can you provide a bit more information. Which schematic exactly are you using? Can you post some photographs of the setup and the schematic?

If it sometimes recognises the propeller and sometimes not, then there could be a few things not right - eg a connection not properly soldered, or a power supply not filtered properly.

We should be able to get this working if we have a bit more information.

solarprism

i used the schmatic with 3 transistor
i will take some photos now and upload it

Dr_Acula

Can you just quickly check what volts are on the DTR line pin 4. It should be minus 9 or minus 12V.

solarprism

somehow,unknown,it works agian .DTR is -12v
the world has many thing that can't explain >-<

Dr_Acula

-12V is correct.

Soldered or breadboard connections? Maybe a dry joint.

Good to hear it is working.

solarprism

Dr_Acula wrote: »

-12V is correct.

Soldered or breadboard connections? Maybe a dry joint.

Good to hear it is working.

yes, a breadboard connection is loosen