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FTDI Friend: Serial TTL communication only
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Please be positive and constructive with your questions and comments.

FTDI Friend: Serial TTL communication only

by olegyk on Tue Jul 10, 2012 12:14 pm

I would like to use FTDI Friend to communicate with AVR controllers (Arduino, ATtiny2313), which have hardware USART, via TTL / USB, which is provided by FTDI. I need serial communication only, not programming the AVR.

I am thinking of connecting FTDI -> AVR:
- VCC -> VCC
- GND -> GND
- TX -> RX
- RX -> TX
- RTS -> RESET

1. Not clear why on FTDI Friend as shipped, VCC is +5 and Signal is +3V. Should they both be +5V?

2. Should CTS be connected anywhere on AVR, or be connected to GND, or nothing?

3. I would like automatic reset when serial is connected (e.g. in Arduino when Serial Monitor is open, or running "screen" or PUTTY). That is I need to "click" RESET to reset, not hold RESET to program. Should I connect RTS or DTR to RESET? (*)

4. Connecting RTS (or DTR) to RESET, should a capacitor be used, and if so which value?

(*) I understand that RESET can also be connected via switch to GND with 10K R pullup to VCC.

Thank you for your time.

olegyk
 
Posts: 3
Joined: Sun Mar 18, 2012 6:40 am

Re: FTDI Friend: Serial TTL communication only

by adafruit_support_bill on Wed Sep 05, 2012 5:55 am

1. The FTDI friend runs on 5v, but is compatible with both 3v and 5v logic.
2. No need to connect CTS
2. RTS is used on the Arduino
3. 100nF should work

adafruit_support_bill
 
Posts: 77925
Joined: Sat Feb 07, 2009 10:11 am

Please be positive and constructive with your questions and comments.