Datasheet
UART via USB
Modern PC computers, laptops and notebooks are 
no  longer  equipped with  RS-232 connectors  and 
UART controllers.  They are nowadays  replaced  with 
USB connectors and USB controllers. Still, certain technology 
enables UART communication to be done via USB connection. 
FT232RL from FTDI® convert UART signals to the appropriate USB 
standard. In order to use USB-UART module on EasyAVR
™
 v7, you must 
rst  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 (CN4), and 
microcontroller  UART  module.  To  establish  this  connection, 
you  must  put  J23  and  J12  jumpers  in  the  USB-UART 
position, and  connect  RX  and TX lines to the 
appropriate pins of the microcontroller. 
This  connection is  done  using DIP 
switch SW10.
RX-FTDI
RX-232
TX-FTDI
TX-232
J23
J12
DATA BUS
1
2
3
4
5
6
7
8
9
10
11
12
13
14 15
16
17
18
19
20
21
22
23
24
25
26
27
28
TXD
DTR#
RTS#
VCCIO
RXD
RI#
GND
NC
DSR#
DCD#
CTS#
CBUS4
CBUS2
CBUS3
CBUS0
CBUS1
OSCO
OSCI
TEST
AGND
NC
GND
GND
VCC
RESET#
3V3OUT
USBDM
USBDP
FT232RL
U1
FT232RL
VCC-5V
C6
100nF
LD12 LD13
RX-LED1
TX-LED1
R16
4K7
R15
2K2
R18
1K
R26
2K2
1
2
3
4
VCC
GND
D-
D+
CN4
USB B
C1
100nF
C2
100nF
E1
10uF
VCC-5VVCC-5V
TX-FTDI
RX-FTDI
USB UART I
CONNECTOR
FTDI1-D_N
FTDI1-D_P
VCC-BRD VCC-BRDVCC-BRD
VCC-BRD
R57
100K
VCC-BRD
1 2 3 4 5 6 7 8
O
N
SW10
RX
TX PD1
PD3
PD0
PD2
RX-FTDI
TX-FTDI
Figure 7-1: USB-UART connection schematic
Enabling USB-UART
In  order  to  enable  USB-UART 
communication, you must set J23 
and J12 jumpers in the USB-UART 
position, and enable  desired RX 
and TX lines via SW10 DIP switch. 
For example, if you want to enable 
USB-UART  connection  on  UART 
module of the default ATmega32 
chip,  you  should  enable  SW10.1 
(RD0) and SW10.2 (RD1) lines.
DVD://download/eng/software/development-tools/
universal/ftdi/vcp_drivers.zip
page 15
communication
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Unauthorised copying, hiring, renting, public performance 
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EasyAVR
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