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Topic: Adding FT232R chip to Arduino Clone (Read 3006 times) previous topic - next topic


Aug 25, 2011, 07:52 am Last Edit: Aug 25, 2011, 08:05 am by eddiea6987 Reason: 1
Ok fellas so i have been looking at the FT232R chip and trying to figure out what is needed to get this baby working with a home made Arduino using the 328p-pu

I have a breakout board from Sparkfun and when using it to upload a sketch all i need is to connect its Rx to my arduinos tx and its Tx to my arduinos Rx , as well as gnd and power , now according to the latest data sheet provided by sparks the chip use to require some resistor but it says it no longer does  
So aside from the chip , a usb plug and an arduino board what else would i need to make this work? and what other connections must be made?

OH must wire the Dtr ! for proper resetting .... what else as  far as components and connections go?

datasheet also says pin 26 "test" must be grounded for normal operation.
Puts the device into I.C. test mode. Must be tied to GND for normal operation.

I could print the Arduino logo on a box of cereal and sell it as "Arduin-O's"


I have tons of questions but i do not want to blow up the boards , but i have really been wondering this , I went by the Tutorial on the site to making an Arduino on a breadboard and they  use two 10uF capacitors before and after the powersupply , my question is why that value? and should it be changed once made on a pcb as oppose to a breadboard ? and would changing it to a surfacemount  cap mean an adjustment in value?
I could print the Arduino logo on a box of cereal and sell it as "Arduin-O's"


Your main decision is if you want to run it as a 3.3v or 5v system. For 3.3vdc data lines, you wire a jumper from the VCCIO pin to the 3V3OUT pin. To run with 5v systems you jumper VCCIO pin to the VCC pin. You could be cleaver and make it switchable with jumper clips and 3 pin male SIP pins.

The DTR or the RTS signals, either one can be used for the auto-reset function for arduino uploading. This should be wired through a series .1ufd cap to the arduion reset pin. I would run the DTR signal through a 2 pin SIP male pins so that you can enable or disable auto-reset by placing or removing a pin clip.

If you wish to have send and rec LEDs to monitor serial data coming and going the chip will drive them. Best to just follow this Arduino drawing when deciding what features and how to wire up the chip.



Here's a circuit I used for my last PCB.

That's probably the minimum required for a 5v system.

NOTE: VCC-EM is just 5v.
Rob Gray aka the GRAYnomad www.robgray.com


You have too many unclear questions.
Look at any arduino schematic and hook up the same things.  If you have it working already and are just looking to add the breakout board as part of the final design, then you need to connect +5, GND, Rx, Tx, CTS# to your boards ground, and DTR# to a 100nF cap to the reset pin.  If you want to use 3.3V/50mA out of the FTDI chip, hook that up also.

The 10uF caps before/after the regulator are too provide power stability & help reduce any power line noise. A 100nF is added also for high frequency noise.
Same values when surface mounted.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.


Alright gentlemen thank you for the arsenal of info those schematics help A LOT, i dont know why i forget  something as simple as looking at a schematic before asking questions. Thanks anyways.
I could print the Arduino logo on a box of cereal and sell it as "Arduin-O's"

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