Uno as usb to serial, need to bring down voltage

Hello , i am using arduino uno as a usb to serial device. I can not be bothered to buy a 50 dollar converter from my hardware store, altronics. I am a complete noob at this serial conversion. Using my arduino i am trying to serial jailbreak my kindle, which can only take in 1.8v. How do i connect it? Thankyou. here is what i am following: https://www.mobileread.com/forums/showthread.php?t=267541

I have no idea what you're doing (and I'm not going to bother reading the link) but a [u]voltage divider[/u] (2 resistors) can be used to knock-down the voltage.

The load (the Kindle) is in parallel with the "bottom" resistor and it will reduce the voltage, so you want the load resistance/impedance to be high relative to the voltage divider resistance. If you don't know the Kindle's input impedance choose resistors that sum-up to about 1K... that should be low-enough relative to whatever the Kindle's impedance is.

Of course the voltage divider only works one-way. If the Kindle has to transmit, or if there is handshaking, you'll need active level shifters to bring the voltage up to 5V.

$50 for level converter? What planet are we on?

They should be like 50 cents on ebay...

DrAzzy: $50 for level converter? What planet are we on?

They should be like 50 cents on ebay...

He's in Australia apparently.

Anyway, they're charging $26 USD for a FTDI 3.3V breakout board. I'm guessing that is what the OP is not buying. $15 USD for a FTDI 5V breakout board.

http://jim.sh/ftx/ is the breakout board the OP needs to replicate

Yes, how can i do this?

Transmitting 1.8V instead of 5V is easy with a voltage divider. However 1.8V input needs to be boosted up to the levels that the UNO uses for HIGH and LOW.

The parts you need to buy will cost more than the completed unit since you're only buying one of each part.