Showing results for 
Search instead for 
Did you mean: 
New Contributor I

Need Correct Source for TTL-USB Gen-2 Cable confirming to FTDI


FTDI data sheet for TTL-232RG-VSW3V3-WE


shows the pinout and their colors

Standard pinout:

GND (Blk/1),

CTS (Brown/2),


TXD (orange/4),

RXD (yellow/5),

RTS (Green/6)

the only source with such pins colors found in alibaba china

FTDI USB UART RS232 TTL cable for Galileo board

Utech Model Number YT-TTL01-27

the problem: other types with 6-pin connector has different colors arrangement

(not Gnd 1 black and 6 green), but different colors and they do not work, no communication silent PuTTY console

means transmission not correct

other 4 separate pins cable for Raspberry/Arduino separate pins locations like UART 0 on Galileo,

the cable not not conforming to the 6 pin architect of Galileo board, and do not communicate, not sure of the pin names

we do not need to study a cable connection !!

which cable source available ready to use with Galileo 6 pin UART 1 and correct pin arrangment?

4 Replies
New Contributor II

Forget the colors they are meaningless and forget the Utech whatzit. You can get 6 of these for the price of one of those and the pins are labelled for easy reading. Use any color jumpers you like.

New Contributor I


we need correct interpretation of the UART 1 for use with PuTTY to communication with Flash or SD Linux shell.

the cable required has to be RS232 level to USB FTDI , not TTL to USB FTDI?

which one the correct statement since it seems the sold cables TTL type cable

By virtue of the designation xxxx-232-R required for the PuTTY connection while those cable specific for xxxx-3.3V and xxxx-5V

the cables do not work

not testing for cable functions

Arduino does not work by RS232 level only TTL, thus we assume the confusion when they state for Arduino and Galileo they do not means the RS232 connection bu the TTL connection on GPIO as UART levels !

6pin Shows the presence of reset intention on the cable connection

4 pin only T/R and power, will not get that to work, beside it did not work to communicate

which cable known to work directly, with the 5V switch on the Galileo board

Further Questions:

UART function on 5 volt or 3.3 volt TTL level on the Galileo? is that has relation to GPIO 3.3/5 volt level switch position?

does the switch position for I/O 3/5 volt has any thing to do with UART operation ?

UART 1 an RS232 full functioning level or UART level only?

UART 1 does mape to GPIO pins (1,2 for UART 0 and 2,3 for UART 1), thus, UART 1 on GPIO pins not RS232 but TTL UART level connection?

Do we assume all the known facts about GPIO on Arduino apply to Galileo, with caution to some difference may exists?

New Contributor II

The UART header (1x6 labeled "J3" I think) on GEN2 boards signals are TTL level. I don't know if the are affected by the 5/3.3 switch because we leave it at default (5v). A VOM and 10 seconds of time answers that for you. I can tell you however that I have used both ttl-rs323 and ttl-usb and they work fine (regardless of what color jumpers I use ). RX, TX, GROUND. Done.

Don't want to use USB? Here ya go: MAX3232 RS232 Serial Port to TTL Converter Module DB9 Connector with Cable Fo | eBay

We bought these things for like $.89 a piece in quantify 10+. We ordered a dozen of both this one and a dozen of the ttl-USB one's I linked you to above. Trust me they work great.

To answer your other questions there is no signal @ RS-232 levels on the Galileo period. They are all TTL on both UART0 and UART1 regardless of how they are mapped.

I don't do Arduino so I can't answer your last question but I can assure you that switching a pin's direction (in/out) is much slower than on other Arduinos. There are muxes in the path that are controlled via i2c and are slow as dog dirt. We discovered that when trying to interface to an ASONG 1-wire-ish sensor directly. Can't be done on Galileo, though other Arduino flavors accomplish it from what I hear.

Anyway good luck. Trust me getting a serial cable to work with the Galileo are the least of your worries. Order some of the one's I linked you to and move on.

P.S.: Please remember to mark answered when you are satisfied that it is. I forget that all the time ...

New Contributor I

Thank you !!

1- TTL-USB cable did work, Arduino Blue USB end with 4 pins green, white, red, black

2- from adafruit "

There are four wires: red power, black ground, white RX into USB port, and green TX out of the USB port.

The power pin provides the 5V @ 500mA direct from the USB port and the RX/TX pins are 3.3V level for interfacing with the most common 3.3V logic level chipsets."

white RX into USB ===> means not RX on Galileo but receiver input on USB then we

connect output TXO pin2 to white pin RX-usb

RXI Galileo pin3to green pin TX-usb

4th pin 5V to red pin (not marked on my board blank)

6th pin GND to black pin