Recently, I have been using an LCD Display on my robot in my robotics lab. The LCD is plugged into UART2. Sometimes, the cortex will simply not turn on. For some time, I had no idea what was happening. I switched out batteries to no avail. Then I switched out the cortex, everything was fine until today, when the cortex could not turn on again. However, when I unplugged the LCD display, the robot turned on again. When I put it in to UART1, the robot still turned on. Can anyone tell me what is going on? I used LCDs in the past, but this has never happened to me!
Is the insulation on the wires for your LCD cut or frayed anywhere?
It seems to me that one of our teams had a problem like this last year that they attributed to a 4-wire extension cable that had gotten pinched and caused a short.
Then again I might be remembering wrong
Highwayman: I remember the checking the wires, and they were not frayed or damaged. They were fine. Thanks for the reply!
I will see how it turns out with the LCD plugged in to UART1. I am thinking that maybe the backlight is drawing too much power, which might keep the cortex from turning on (???)
The backlight shouldn’t be causing a problem, and it won’t even be turned on unless you have done so in your program. One thing you might want to check is that the two ends of the serial y cable are connected to the correct ports on the LCD. The end with the yellow wire connects to the RX port, while the end with the white wire connects to the TX port.
http://www.vexrobotics.com/wiki/images/b/b3/VEX-LCD-Display.pdf
Hope this helps.
Okay. So I checked the serial cable more closely today and found that one of the cables had some copper exposed near the ends. I think this might have been causing some short-circuiting or whatever. Either way, I replaced the serial cable, and the problem has not recurred yet. Thanks for all the help!