RS232 communication
Posted: Thu Apr 28, 2011 6:03 am
Hello,
I Have some problems with the communication between the screen and my kit of development.
My kit is equipped with a microcontroller from Atmel (AT90CAN128), I use the UART0 to have a dialog with the screen. The setting of my communication are the following: 115200 Baud, 8 bits, no parity, 1 bit stop.
When I connect my kit with a PC, it is functionning normally, and when I connect it with the screen, some bytes are displayed and other no (or I have a rectangular caracter which is displayed).
I try two configuration:
The first one , I set up the HW flow control with my microcontroller in a software manner. I put my RTS pin in a low level and I wait until the screen put it high; but it doesnt work! I look in an oscilloscope the rising edge and I see two times the same pattern for one byte send (but maybe the display understand the first rising pattern like a caracter and the second like my byte).
The second I linked RTS and CTS pin like I see it in an other post, but it didnt work properly, I have still caracters which I dont want.
And the last problem I see, is when I want to send some commands like Set Insertion Point or Clear Screen, the screen didnt understand or it is done with a shift in time!!!
I have make a lot of debug step, with oscilloscope, hyperterminal and so forth but I didnt find where is the problem!
Can you explain me how the RST and CTS signals are used?
Thank you in advance for you answer.
I Have some problems with the communication between the screen and my kit of development.
My kit is equipped with a microcontroller from Atmel (AT90CAN128), I use the UART0 to have a dialog with the screen. The setting of my communication are the following: 115200 Baud, 8 bits, no parity, 1 bit stop.
When I connect my kit with a PC, it is functionning normally, and when I connect it with the screen, some bytes are displayed and other no (or I have a rectangular caracter which is displayed).
I try two configuration:
The first one , I set up the HW flow control with my microcontroller in a software manner. I put my RTS pin in a low level and I wait until the screen put it high; but it doesnt work! I look in an oscilloscope the rising edge and I see two times the same pattern for one byte send (but maybe the display understand the first rising pattern like a caracter and the second like my byte).
The second I linked RTS and CTS pin like I see it in an other post, but it didnt work properly, I have still caracters which I dont want.
And the last problem I see, is when I want to send some commands like Set Insertion Point or Clear Screen, the screen didnt understand or it is done with a shift in time!!!
I have make a lot of debug step, with oscilloscope, hyperterminal and so forth but I didnt find where is the problem!
Can you explain me how the RST and CTS signals are used?
Thank you in advance for you answer.