Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

PIC16F84A to DB9 without MAX232

Status
Not open for further replies.
B

bangunprayogi

Newbie level 5
Joined
May 19, 2005
Messages
9
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,283
Location
Bandung, Indonesia
Activity points
1,361
pic16f84 max232

Hi, I have quetions about serial communication on PIC16F84A microcontroller. Is the PIC16F84A not need the MAX232 level converter? And how the configuration of that connection? I want the example of the schematic.
 

pic16f84a max232

Since the PIC16F84A does not have a serial port, you will drive the TxD pin and sample the RxD pin in SW. If you invert the levels in SW, you can connect the PIC to the RS-232 using just two resistors: about 220~330Ω in series with TxD and RxD.
Tried, tested and true.

Or, use two 74HC04 gates. Use 330Ω in series with TxD and 47-100kΩ in series with RxD. Now you do not need to invert the signals in software. This will also work with dedicated serial ports.
 

max232 con db9

As you see, you can't connect PICs Rx and Tx directly to DB9. So, the question is, why don't you want to use MAX232 (or its no-external-capacitors version MAX233)?
You do need some sort of circuit to invert these signals anyhow..
Regards,
IanP
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top