Andres Felipe Vargas

Monitor  HC908q

Discussion created by Andres Felipe Vargas on Feb 7, 2006
Latest reply on Feb 7, 2006 by Eckhard Gosch
Hi everyone
 
I recently bought a HC908qy4, And I made a circuit to get the monitor mode following the AN2305 and 2317 application note.
 
I could achieve the connection between the Pemicro software and the hc908qy4, but I after I programmed the micro, i could not achieve the connection again, I checked and rechecked the connection, but i could not achieve anything, but when I replace de Vtst voltage from the max232 and zener diode (9.1V) with an external source of Vtst (lm78l08) I get the connection again.
 
I don´t understand what this happen, I someone can help me, I would appreciate it
Andres

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