I want to build a USB Programmer currently for AT89C51. I am stuck on how to make it communicate with PC. In RS232, the RxD TxD pins are straight forward, we just need to use Logic Level Converter to interface with MC. What about USB. Are Data+ Data- lines equal to RxD TxD? Can I connect these USB Data lines to MC directly? They don't need any Logic Level Converters. Right?
I saw some USB to RS232 converters. Why they exist? I thought USB interfacing was more easy, not really!
So how would i send data from PC to my Programmer through USB port? Please Help & Thank you