FT232R and Arduino Uno


I am struggling with something that suppose to be simple,communicate between and FT232R and an Atmega328 ( with arduino bootloader on it ). So i use the microcontroller on the breadboard and send the program with my arduino uno it's working fine ( i use this tutorial ) . Then i try to do the same thing with the FT232R but not working ( i use this tutorial ).

So i am not sure what is not working and also i am not sure to understand the role of the RESET pin on the arduino uno.

When the reset pin of the arduino UNO is not connected to the RST pin of the Atmega328 i can't upload even if with the resistance connected to VCC.

So what do i do wrong with the FT232R and why the FT232R does not have a RESET pin ?

All the best


The lesson you need to learn is all about detail.

An FT232R would appear to be just a chip. This is pretty useless on its own - you have to mount it on a PCB with the support components and connectors.

I rather presume you mean you have a USB to TTL module using a FT232R chip, with some array of connections, so you need to give us a link to which module you actually have in front of you. In any case, it will have a DTR pin which you need to connect to the ATmega238 reset pin via a 0.1 µF capacitor in addition to a 10k pull-up resistor on that reset pin.

If you then have difficulty, you had better give us a perfectly focussed, outdoor daylight photograph of your setup to determine what else may be wrong.

Hi, Thanks a lot for your answer, i google the DTR pin with capacitor but i am not sure how to plug it.I find this schematic online, Does it look correct ?

100nF 10kOhm
DTR -----||------+------^v^v^----- VCC

All the best


Reset pin should be connected to both one side of the capacitor and the other side of the diode (connected where the + is in that line). I can't tell where you have it because the spacing gets messed up.


        100nF           10kOhm

DTR -----||------±-----^v^v^----- VCC

Yep, that’s it - though a diode “pointing” from reset to the Vcc in parallel with the 10k resistor is also advised.