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You can only test ONE CABLE at a time

Step 1 - CHIP TEST

Plug in the cable into your computer (we will use Windows)

Go to the Device Manager (From the Start Menu, select Settings→Control Panel. Double click on System and select the Hardware tab. Then click on the Device Manager button)


When plugging in a USB cable, the window will refresh and you will see USB Serial Port (COMx)

If the new COM port doesn't show up, there is a problem with the cable


This is the end of your FTDI Cable

We added breakout wires to make it easy to measure voltages

Test voltage between black and red wires - it must be 5V

Test voltage between black and orange wires - it must be 3.3V (NOT 5V)

If test voltages are not 5V and 3.3V, the cable is bad

Install software

Download X-CTU:

Install software

Start up software

Select the COM port that says USB SERIAL PORT

Click on TERMINAL tab

STEP 3: Test RX and TX

Test TX is not shorted to RX

FTDI cable has nothing attached to it

Type text into terminal window. All text should be blue. If red text appears, the cable is bad.

When done, click Clear Screen

Test RX and TX

Connect 100 ohm resistor between orange and yellow wires

Type text into terminal window, all characters will appear in blue AND red

If red text does not appear, cable is bad

STEP 4: Test CTS

We will test the CTS pin. Connect 100 ohm resistor between brown and red wires

On terminal, CTS box is black. If it is not black, cable is bad.

Now connect 100 ohm resistor between brown and black wires

On terminal, CTS box is green. If it is not green, cable is bad.

STEP 5: Test RTS

RTS short test

FTDI cable has nothing attached to it

Look at window, make sure RTS box is clicked and CTS is BLACK. If CTS is green, cable is bad

RTS function test

Put 100 ohm resistor between Yellow and Brown wires

When RTS box is clicked, CTS box is GREEN

When RTS box is not clicked, CTS box is BLACK

If CTS box does not change color from black to green , cable is bad

Quit software

After each cable, quit software then unplug cable

/home/ladyada/public_html/wiki/data/attic/ftditest.1281115068.txt.gz · Last modified: 2016/01/28 18:05 (external edit)