MP3Car.com - View Single Post - Renault "Tuner List" Head Unit/CD changer hacking

Vicne · 02-27-2006, 07:37 PM

Quote: Originally Posted by Ale

Are you sure that this pullup can supply almost 12V at pin 14? what value have you tried?

The pull-up still was 4K7 but it seems it's not needed.
I think voltage measurement of 5.7V when putting this resistor to ground shows that there most probably is some internal pull-up and we can safely leave an open collector, right ?

For the sake of completeness, here's the circuit I'm using. Now finally I think more people (without a CDC) can enter the game :-)

Note : having re-read the MAX3232 Data Sheet this afternoon, it seems I should replace the three 0.1uF capacitors at pins 2, 6 and between 4 and 5 by 0.47uF ones as my power supply is 5V and not 3V (see table 2, page 9)

Thanks again for your insightful input, as well as pippolippi's.

02-27-2006, 07:37 PM	#245
Vicne Variable Bitrate Vicne's CarPC Specs Join Date: Apr 2005 Location: Belgium Vehicle: 2005 Renault Scenic Posts: 325 My Photos: ()	Quote: Originally Posted by Ale Are you sure that this pullup can supply almost 12V at pin 14? what value have you tried? The pull-up still was 4K7 but it seems it's not needed. I think voltage measurement of 5.7V when putting this resistor to ground shows that there most probably is some internal pull-up and we can safely leave an open collector, right ? For the sake of completeness, here's the circuit I'm using. Now finally I think more people (without a CDC) can enter the game :-) Note : having re-read the MAX3232 Data Sheet this afternoon, it seems I should replace the three 0.1uF capacitors at pins 2, 6 and between 4 and 5 by 0.47uF ones as my power supply is 5V and not 3V (see table 2, page 9) Thanks again for your insightful input, as well as pippolippi's. Attached Images __________________ Vicne SPDIF CarPC V2 - Tuner List CD Changer Emulator - Chris Conty Last edited by Vicne : 02-27-2006 at 07:51 PM.