PIC 18F4620 + RFID reader TTL

[Knight_FlyCn]

I have a project. Read tag in RFID and send to PIC 18F4620. After pic send to PC. See by terminal.
I connect pic and reader so by pictuer
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Who can help me code ?. I coding but don't work
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Thinh

[ezflyr]

Hi,

Unless you show us what you've already done, it's not very likely that you'll receive any help. This is a 'help you' forum, not a 'do it for you forum'!

As shown, you have a serious hardware problem. The Tx output of the RFID module, and the Tx output of the USB-to-Serial converter IC are wired to the same Rx input on the PIC. That won't work. If you need two serial ports, you need to decide which serial data source is the higher priority, and use the hardware UART on the PIC for that source. The other source can use a software serial port.

A couple of comments:

1. You really need to break your project up into manageable 'chunks'. For example, get your serial communications working with the PC first before you attempt to get the RFID reader working. That PL2303 is really old, and it's got a really high pin count (which makes wiring mistakes more likely). Consider a simpler, more modern equivalent, or use RS232 with a MAX232 instead.

2. Post a link to your RFID reader. Clearly, you've got some hardware issues to resolve. Don't keep us in the dark about the actual hardware you are using.

3. Do you know that your PIC is actually running? Can you blink an LED at a predictable rate?

4. Post the code you've got so far!

John