Topics

#I2C Level Converters #i2c

Arv Evans
 

Hello

I recently purchased a package of these I2C level converters.  Have not tried them yet though.


Anyone out there with experience with these modules?

I got them thinking that they could allow me to do 3.3V  I2C communications without having to modify
my Arduino Nano modules for lower voltage, and thus slower speed.

Arv
_._




Owen Vinall
 

Hi Arv Evans,
I'm a complete newbie to Amateur Radio but not electronics Arduino's etc. I have used the same ? level converters in an Usb Rs232 5 volt logic to 3.3 ? logic conversion when uploading code to my Esp8266's. All the Esp' logic pins including Tx and Rx run on 3.3 and are rather intolerant to 5 volts. It's really the 3.3 volt Rx into the Esp that matters. I have flashed / Arduino sketches into Esps at least 100 times with no issues.(I have around 8 Esp's some have their Rx pins fried as I tried using 5 volts. Never trust a Usb to Rs232 if it states 3.3 logic without checking.).
Esp's in CERTAIN areas easily rival Arduino's

Owen Vk5fkov




Sent from my SAMSUNG Galaxy S7 on the Telstra Mobile Network


-------- Original message --------
From: Arv Evans <arvid.evans@...>
Date: 20/2/20 8:49 am (GMT+09:30)
To: BITX20@groups.io
Subject: [BITX20] #I2C Level Converters

Hello

I recently purchased a package of these I2C level converters.  Have not tried them yet though.


Anyone out there with experience with these modules?

I got them thinking that they could allow me to do 3.3V  I2C communications without having to modify
my Arduino Nano modules for lower voltage, and thus slower speed.

Arv
_._




Tom, wb6b
 

Hi,

I bough a pack of five some time ago, also. 

Here is an Adafruit note along with links included in the note that may offer more information.

https://www.adafruit.com/product/757

Luckily the 5v Nano boards seem to be just barely in spec when connected to 3.3v parts and the pullup resistors tied to 3.3 volts. Such as with the 3.3v synthesizer chip used on the uBitx. 

I'm sure the ones I bough will come in handy at some point. They were definitely inexpensive to buy just in case I need them.

Tom, wb6b

Ismo Väänänen OH2FTG
 

My homebrew ubitx has those exact levels shifters between the arduino nano and the silabs synth and it works great.

Kees T
 

Hello Arv,

I have used 2N7002 FETs and 2 resistors for that function for many years .....I wonder if those parts are 2N7002s.

73 Kees K5BCQ

Arv Evans
 

Thanks Tom.  I noticed that some of the 4-channel level shift boards have differing
pin-outs.   Could be slightly confusing if using multiple boards for the same project. 

Arv
_._


On Thu, Feb 20, 2020 at 1:31 AM Tom, wb6b <wb6b@...> wrote:
Hi,

I bough a pack of five some time ago, also. 

Here is an Adafruit note along with links included in the note that may offer more information.

https://www.adafruit.com/product/757

Luckily the 5v Nano boards seem to be just barely in spec when connected to 3.3v parts and the pullup resistors tied to 3.3 volts. Such as with the 3.3v synthesizer chip used on the uBitx. 

I'm sure the ones I bough will come in handy at some point. They were definitely inexpensive to buy just in case I need them.

Tom, wb6b

Arv Evans
 

Kees

Thanks for the reply.  I have used the discrete component level shifter for several
projects, but this is my first try at using the integrated modules from an EBay seller. 
Circuit seems to be the same 2-restotrs and a 2N700x, so I'm not anticipating
any problems. 

Arv
_._


On Thu, Feb 20, 2020 at 9:11 AM Kees T <windy10605@...> wrote:
Hello Arv,

I have used 2N7002 FETs and 2 resistors for that function for many years .....I wonder if those parts are 2N7002s.

73 Kees K5BCQ

MadRadioModder
 

Yup. Use those all the time.  Work ok… Close to spec, meaning range is 0.8-3.1 V (Lo-Hi).

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Arv Evans
Sent: Wednesday, February 19, 2020 4:19 PM
To: BITX20@groups.io
Subject: [BITX20] #I2C Level Converters

 

Hello

 

I recently purchased a package of these I2C level converters.  Have not tried them yet though.

 

 

Anyone out there with experience with these modules?

 

I got them thinking that they could allow me to do 3.3V  I2C communications without having to modify

my Arduino Nano modules for lower voltage, and thus slower speed.

 

Arv

_._

 

 

 

 


--

…_. _._