Page 1 of 7
SparkFun USB UART Breakout (CY7C65213)
Hookup Guide
Introduction
The CY7C65213 USB to UART serial breakout is designed to provide users
with a means to access all available I/O pins on the CY7C65213 part and to
provide a 6-pin UART header that is compatible with other SparkFun
breakout boards. This tutorial will explain the use of the board in greater
detail.
SparkFun USB UART Serial Breakout CY7C65213
BOB - 13830
We will explain the layout of the board, proper usage of the jumpers on the
board to change the I/O voltage, and use of the Cypress configuration
application to change default settings on the board to meet your own
needs.
As we work through the Hookup Guide, you may find it useful to have the
CY7C65213 USB to UART Datasheet on hand.
C Y 7C 65 21 3 USB TO UAR T DATASHE ET
Suggested Reading
Page 2 of 7
At a minimum, you should be familiar with asynchronous serial
communication, as that is the central function of this chip. You should also
have some idea of what we mean when we talk about different logic levels,
or voltages, so you know when to change the logic level for your board.
Hardware Overview
Here we will go over the various parts of the board, providing an
explanation for each and detailed usage instructions.
• Micro-B USB port—This is where the cable from the host device
connects to this PC. Power can be supplied through this connector to
this board, as well as to the circuit it is attached to.
• USB signal lines—These two pads break out the D+ and D- signal
lines for user access. These signals can then be brought out to a
different connector if desired.
• VIO selection jumper—This jumper is used to select the voltage
that appears at the VIO pin on the 6-pin serial header. The left two
pads can be closed to supply 5V directly from the USB power line, or
the right two pads can be closed to supply 3.3V via an onboard
500mA regulator. If the attached board is going to provide a voltage
reference for an alternative voltage (say, 2.5V or 1.8V), remove all
solder from this jumper.
• 5V pin—Supplies 5V directly from the USB power.
• 3.3V pin—Supplies 3.3V from a 500mA 3.3V regulator connected to
the USB power line.
Page 3 of 7
• VIO pin—Tied to the VIO pin on the 6-pin serial header, this will
either be connected to 5V or 3.3V, depending on the VIO selection
jumper, or it will reflect the voltage present on VIO if the downstream
board is providing a reference voltage for this board.
• Variable purpose I/O pins—The purpose of these pins will be
discussed later, but in normal operation they are seldom, if ever,
used.
• DTE port pins—These pins provide the same functionality as the
similarly named pins on an RS-232 port, albeit at VIO voltage rather
than the bipolar voltage of true RS-232. DTR and CTS are the most
commonly used. We’ll discuss the role of these pins later.
• TX and RX LEDs—These LEDs light up when data is being
transferred over the serial channel. The TX LED lights up when data
is being sent from the host to the attached board, and the RX LED
lights up when data is being sent back from the attached board to the
host.
• 6-pin serial header—A longtime standard on SparkFun (and other)
boards, this header contains the minimum necessary signals for
Page 4 of 7
communicating with a downstream board. It can be used to program
Arduino Pro and Pro Mini boards, among others.
• Low-voltage select jumper—On the underside of the board, you’ll
find a jumper that should only be set in cases where VIO is 2V or
less. Since there is no onboard reference for that voltage, this will be
in cases where the downstream board is providing the reference
voltage.
Programming an Arduino Pro or Pro
Mini
The CY7C65213 chip can be used to program an Arduino Pro or Pro Mini,
just like SparkFun’s other FTDI-based USB to UART chips. As a basic
example for getting started with this board, we will be demonstrating this
hardware connection.
Having a hard time seeing the circuit? Click on the wiring diagram for a
closer look.
Note that, unlike the other boards, you’ll need to buy some kind of header
to interface to the Arduino board, as no header comes pre-soldered to the
CY7C65213 breakout. This affords you the option to choose the connector
that best suits your purpose or to solder wires directly between the two
boards.
Don’t Forget! Double check that the VIO Selection Jumper is set to
the appropriate voltage level for the board you are connecting to
(5V/3.3V). If you are connecting to a board with a different reference
voltage, remove all solder from this jumper before powering up your
circuit.
Once the board is connected and the driver is installed (which should
happen automatically on all major operating systems), no other changes
are needed for the board to be used as a programming connection. Simply
select the COM or TTY port in the Arduino software and proceed as normal.
Using the Board at Voltages Below 2V
Page 5 of 7
Hardware Changes on the PCB
To enable support for voltages below 2V, you must first disconnect the
board from your PC and adjust the jumpers on the PCB.
Shown below is the VIO selection jumper. You must remove all solder
from this jumper before proceeding. We suggest using some solder wick
to achieve this.
Now, you must close the low-voltage jumper on the bottom side of the PCB
with solder.
We’ve created a special footprint just for solder jumpers to make it as easy
as possible to close the jumper. Simply heat both pads and then apply the
solder to the pads; a bridge should form naturally. Do not apply too much
solder.
Software Settings on the PC
Cypress offer a downloadable configuration utility for this chip. Sadly, it is
currently offered only for the Microsoft Windows platform. You’ll need to
download and install this utility before you can use the chip for voltages
below 2V.
When you first open the utility, this is what you will see. In the lower left,
you should see the utility displaying the number of Cypress USB UART
boards only (other manufacturers' chips, such as FTDI, Arduino or Prolific
will not be reflected in this number). Assuming your chip has shown up
here, go ahead and click on the Select Target tab at the top.
Page 6 of 7
This is the Select Target tab. The dropdown will list available Cypress USB
UART boards, and information (probably more than you want or need) will
appear in the window below it. Click the Connect button to proceed,
making sure that there are no open terminal windows (such as the Arduino
IDE serial port monitor) using this board at the moment first.
A new tab will appear and become automatically selected. In the lower left
corner of this new tab, you can see a checkbox labeled VCCIO voltage is
less than 2V. Click this checkbox, then click the Program button at the
bottom of the page. The chip is now configured for use at less than 2V.
Resources and Going Further
For more on the Cypress CY7C65213 USB UART chip, please check out
the links below:
• USB UART SDK from Cypress — If you are an experienced systemlevel software developer, it’s possible to use the Cypress drivers to
achieve additional goals with the 7C65213 chip. It has onboard I/O,
for instance, which can be used for out-of-band communications with
the target PCB.
• CY7C65213 USB UART Breakout Schematic (PDF)
• CY7C65213 USB UART Breakout Eagle Files (ZIP)
• CY7C65213 USB UART Datasheet (PDF)
• SparkFun CY7C65213 USB UART Breakout GitHub Repository
(hardware source files)
Check out these related tutorials for some inspiration for your next project:
Page 7 of 7
Das Blinken Top Hat
RFM69HCW Hookup Guide
A top hat decked out with LED strips
makes for a heck of a wedding gift.
The RFM69HCW is an inexpensive
transceiver that you can use to
create all kinds of wireless projects.
This tutorial will help you get started.
nRF52832 Breakout Board
Hookup Guide
Mini GPS Shield Hookup
Guide
How to hookup and program (in
Arduino!) the nRF52832 Breakout -a development board for Nordic's
BLE/ANT/2.4GHz system on chip.
A hookup guide for the SparkFun
Mini GPS Shield.
https://learn.sparkfun.com/tutorials/sparkfun-usb-uart-breakout-cy7c65213-hookup-guide?... 2/13/2017