UART via USB
Modern PC computers, laptops and notebooks are
no longer equpped with RS-232 connectors and
UART controllers. They are nowdays replaced with USB
connectors and USB controllers. Still, certain technology
enables UART communication to be done over USB connection.
Controllers such as
FT232RL
from FTDI® convert UART signals
to the appropriate USB standard. In order to use USB-UART module
on EasyPIC
™
v7, you must first install FTDI drivers on your
computer. Drivers can be found on
Product DVD
:
USB-UART communication is being done through a
FT232RL controller, USB connector
(CN32)
, and
microcontroller UART module. To establish this connection, you
must put
J3
and
J4
jumpers in the
USB-UART
position,
and connect
RX
and
TX
lines of the microcontroller
to the appropriate input and output pins
of the FT232RL. This selection is
done using DIP switches
SW1
and
SW2
.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
RX-FTDI
RX-232
LED
C32
100nF
RX-LED
TX-LED
LD41
LD42
R9
4K7
R8
2K2
VCC-MCU
VCC-MCU
C50
100nF
VCC-5V
E12
10uF
VCC-5V
C34
100nF
VCC-MCU
1
2
3
4
VCC-5V
VCC-MCU
R78
4K7
10K
R79
VCC
D-
D+
GND
CN32
USB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
U2
FT232RL
TXD
DTR#
RTS#
VCCIO
RXD
RI#
GND
NC
DSR#
DCD#
CTS#
CBUS4
CBUS2
CBUS3
OSCO
OSCI
TEST
AGND
NC
CBUS0
CBUS1
GND
VCC
RESET#
GND
3V3OUT
USBDM
USBDP
RX-FTDI
TX-FTDI
FTDI
TX-FTDI
TX
J4
ON
TX-232
RA2
RB7
RC4
RD6
RC6
RB5
RB2
RB1
SW2
DIP SW 8
M1X3
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
RX
J3
ON
RA3
RB5
RC5
RD7
RC7
RB2
RB1
RB4
SW1
DIP SW 8
M1X3
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
DATA BUS
Figure 7-1:
USB-UART
connection
schematics
Enabling USB-UART
In order to enable USB-UART
communication, you must set
J3
and
J4
jumpers in the
USB-UART
position, and enable desired
RX
and
TX
lines via
SW1
and
SW2
DIP
switches. For example, if you want
to enable USB-UART connection
on UART1 module of the default
PIC18F45K22
chip, you should
enable
SW1.1
(RC7) and
SW2.1
(RC6) lines.
DVD://download/eng/software/development-tools/
universal/ftdi/vcp_drivers.zip
page 17
communica
tion
19122011
www.mikroe.com
Copyright ©2011 Mikroelektronika.
All rights reserved. Mikroelektronika, Mikroelektronika logo and other
Mikroelektronika trademarks are the property of Mikroelektronika.
All other tradmarks are the property of their respective owners.
Unauthorised copying, hiring, renting, public performance
and broadcasting of this DVD prohibited.
Ava
ilable
on Produc
t D
VD
!
