Interfacing 5v (Rd/Tx) to 3.3v (Tx/Rx) - Electronic Circuits Projects Diagrams Free

Sync · 28th May 2009, 04:10 AM

Hello,

I'm using an Arduino (5v) and the device is a Skytraq-Venus634FLPx GPS module that is 3.3v LVTTL UART http://www.sparkfun.com/datasheets/G...Px_DS_v051.pdf

I've heard about Bipolar transistors that can do the job. I don't know more and can't go any further as my skills reach the limit at this point.

Anyone ?

Thanks!

Pommie · 28th May 2009, 04:21 AM

Have a read of Microchips hints and tips.

Mike.

Arumugam · 28th May 2009, 05:39 AM

Hi,
So many level translators are available in the market and also it's very cheap.And for your reference some of the level translator part~ for 5V to 3.3V and vice versa
Voltage Level Translation - Dual Supply Translators - SN74LVC2T45 - TI.com
This device will solve your problem.Any further clarifications please mail me on aarupk@gmail.com

UTMonkey · 28th May 2009, 12:50 PM

I have had the 74HCT125 recommended to me. Works great in my SD Project.

AtomSoft · 28th May 2009, 01:42 PM

The 74HCT125 is awesome for SD since its a QUAD piece. You might find it more usefull using that part. The SN74LVC2T45 is a OCTAL part which may be a overkill.

I think its ok if you connect the 3.3v output to a 5v input aka 3.3v Tx pin to micro but for the input pin use that IC. You could use the IC for both if you wish.

I never tried this but maybe you can convert the 3.3v logic to a 5v logic:
I assume you need to setup like

1A = 3.3v
1Y = 3.3v Rx Pin on GPS module
1OE = TX on PIC

2A = 5v
2Y = Rx on PIC
2OE = 3.3v TX Pin on GPS module

If im wrong please correct me.

Be aware that this IC : "outputs enable inputs (OE = active LOW)"

A "74AHC126" would be the best for this i think

Arumugam · 29th May 2009, 05:45 AM

I will not recommed the HCT,HC series buffer.And 74HCT125 is not a level translator.Use level translator only.Level translator only solves your problem

Sync · 29th May 2009, 07:07 AM

@Arumugam, i let you know if i suceed. Thanks for all the help gals and guys!

Wp100 · 29th May 2009, 10:04 AM

If you can find them in your area the Texas chips TXB0104 - 4 bit and TXB0108 - 8 bit, are much simpler to use - although only available in smd.

They are true 4 / 8 bit dual voltage bidirectional voltage level translators with auto direction sensing.

see - http://focus.ti.com/lit/ds/symlink/txb0104.pdf

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar
Title	Starter	Forum	Replies	Latest
interfacing a PC	uranium05r	Electronic Projects Design/Ideas/Reviews	9	1st February 2009 06:30 AM
Interfacing A Car	hgfd7ert	Micro Controllers	6	21st October 2007 03:47 AM
Interfacing USB with PIC	Pirasath	Electronic Projects Design/Ideas/Reviews	7	15th September 2005 11:24 AM
INTERFACING WITH C	aibelectronics	Electronic Projects Design/Ideas/Reviews	16	5th August 2005 04:40 PM
Interfacing between 5.0V and 3.3V IC	StupidDum	General Electronics Chat	3	5th November 2004 03:02 PM

28th May 2009, 04:10 AM	#1
Sync	Interfacing 5v (Rd/Tx) to 3.3v (Tx/Rx) Hello, I'm using an Arduino (5v) and the device is a Skytraq-Venus634FLPx GPS module that is 3.3v LVTTL UART http://www.sparkfun.com/datasheets/G...Px_DS_v051.pdf I've heard about Bipolar transistors that can do the job. I don't know more and can't go any further as my skills reach the limit at this point. Anyone ? Thanks!

28th May 2009, 04:21 AM	#2
Pommie	Have a read of Microchips hints and tips. Mike.

28th May 2009, 05:39 AM	#3
Arumugam	Hi, So many level translators are available in the market and also it's very cheap.And for your reference some of the level translator part~ for 5V to 3.3V and vice versa Voltage Level Translation - Dual Supply Translators - SN74LVC2T45 - TI.com This device will solve your problem.Any further clarifications please mail me on aarupk@gmail.com

28th May 2009, 12:50 PM	#4
UTMonkey	I have had the 74HCT125 recommended to me. Works great in my SD Project.

28th May 2009, 01:42 PM	#5
AtomSoft	The 74HCT125 is awesome for SD since its a QUAD piece. You might find it more usefull using that part. The SN74LVC2T45 is a OCTAL part which may be a overkill. I think its ok if you connect the 3.3v output to a 5v input aka 3.3v Tx pin to micro but for the input pin use that IC. You could use the IC for both if you wish. I never tried this but maybe you can convert the 3.3v logic to a 5v logic: I assume you need to setup like 1A = 3.3v 1Y = 3.3v Rx Pin on GPS module 1OE = TX on PIC 2A = 5v 2Y = Rx on PIC 2OE = 3.3v TX Pin on GPS module If im wrong please correct me. Be aware that this IC : "outputs enable inputs (OE = active LOW)" A "74AHC126" would be the best for this i think __________________ AtomSofts eBay Store AtomSoftTech: C18 TIPS & TRICKS v9 PDF Nokia 6100 Driver/Software My Name: Jason Lopez http://atomsofttech.info/ \| My YouTube Videos! My Favorite Store: dipmicro Electronics Last edited by AtomSoft; 28th May 2009 at 01:46 PM.

29th May 2009, 05:45 AM	#6
Arumugam	I will not recommed the HCT,HC series buffer.And 74HCT125 is not a level translator.Use level translator only.Level translator only solves your problem

29th May 2009, 07:07 AM	#7
Sync	@Arumugam, i let you know if i suceed. Thanks for all the help gals and guys!

29th May 2009, 10:04 AM	#8
Wp100	If you can find them in your area the Texas chips TXB0104 - 4 bit and TXB0108 - 8 bit, are much simpler to use - although only available in smd. They are true 4 / 8 bit dual voltage bidirectional voltage level translators with auto direction sensing. see - http://focus.ti.com/lit/ds/symlink/txb0104.pdf