bmhong WROTE:I use the TX output connect to RC7(PIC16F877A),but the lcd show some strange symbol!Can tell me what is the problem?
Woh... there is 2 things here need to be clear.
1. The transmit from ultrasonic, it is UART? If not, surely you cannot connect to PIC' RX pin directly. The ultrasonic does not have datasheet or User's Guide? Oh... the Maxbotix? OK, I got it now, most of their ultrasonic Tx output is RS232 but half standard only. Because it is 0-5V. It do state in the datasheet, look carefully.
2. And the program you written for the whole "translation", have you tested it? a quick way is to use any terminal program on computer, connect to your microcontroller, and type any key. If the program is correctly written, you should see something. Yes, it might also be the LCD problem