problem with connecting usb to intel 80c51

[WestDike]

Hi i've got problem cuz i don't have idea how to connect usb to microcontroller 80c51 and maybe can sb tell me is the rest connected well?

 

[betwixt]

You can't connect USB directly, the 80C51 does not have the necessary hardware to talk to a USB interface. The simplest method is to get hold of an inexpensive USB serial interface and connect it's MCU side to the 80C51 TXD and RXD pins. Look for FT232, PL2303 or CP2102 devices for information on how to wire them together.

Check how the capacitor is connected to the RST pin and whether EA should have a pull-up resistor.

Brian.

 

[AskSensors]

Hello,

It's a little bit complicated to Build a USB interface with MCU that don't support USB.
If you can move to an MCU already integrating a native USB interface, it will be better!
However, if not, you can take a USB to Serial UART interface like the FT232R "which simplifies USB to serial designs and reduces external component count by fully integrating an external EEPROM, USB termination resistors and an integrated clock circuit which requires no external crystal into the device"

Hope it helps

 

[ark5230]

If the USB is used for 5 V power for microcontroller that should be OK
for communication or programming search for necessary details.

 

[baileychic]

RST pin of 80C51 needs to be pulled low that is connected to ground through a 10k resistor.

USB +5V needs to be connected to VDD pin of 80C51 and USB GND pin to VSS pin of AT89C51. This will power the microcontroller. Check EA pin connection.

 

[FvM]

RST pin of 80C51 needs to be pulled low that is connected to ground through a 10k resistor.

RST pin has an internal weak pull-down on all CMOS x51 processors. An external resistor isn't necessarily required.

 

[Ivan_Ryger]

The 80C51 does not have enough computing power to process enough instructions to decode the USB protocol. Better way is to use FT232 chips externally and take the benefits of already implemented RS232 interface in the controller.