Using a non-TXB0108 logic level converter for SX1276 sensor

Projects Networking, Protocols, and Devices
1

Hi! I would like to ask this question.

Most of the answers I saw from the forum recommend they use something like the TXB0108 8-channel logic level converter for the SX1276 LoRa sensor. I am using an Arduino UNO for this case, converting 5V logic level to 3.3V for the sensor to work.

Is it okay to use a non-TXB0108 converter? It's something like this, you can refer to the link attached below.

Any input would be much appreciated. Thank you very much.

Link: Logic Level Converter 8 Channels Bi-Directional

2

Yes, it works the same.

Regards

3

Thanks for the reply. How about an TXS0108E? I believe it costs lower than the TXB0108, and is more common in online shops. Something like this.

Link: Level Shifter - 8 Channel (TXS0108E) Hookup Guide - SparkFun Learn

4

All level shifters are just that, level shifters, and serve the same purpose.

Regards

5

Hi. Would like to ask for help on how to connect the SX1276 Sensor to the TXB0108 Level Shifter using Arduino UNO.

I noticed that there are two Vccs (A and B) on the level shifter, labelled for 3.3V and 5V. Since I am running on an UNO, can I use the 5V pin to connect to B and and the 3.3V pin to A? Or what will be the proper workaround?

Any inputs are much appreciated. Thanks.

6

5V from UNO to B
3.3V from SX1276 to A
GND common to all plates.

7

have a look at the discussion in post interfacing-sx1276-with-arduino-uno

I would recommend moving to a microcontroller which uses 3.3V logic, e.g. Arduino Pro mini 3.3V, ESP32, ESP8266, Arduino Due, etc

reduces the wiring which is a major cause of poor connections and intermittent faults

pert 8

I have merged your topics due to them having too much overlap on the same subject matter @ryukiishima.

In the future, please only create one topic for each distinct subject matter and be careful not to cause them to converge into parallel discussions.

The reason is that generating multiple threads on the same subject matter can waste the time of the people trying to help. Someone might spend a lot of time investigating and writing a detailed answer on one topic, without knowing that someone else already did the same in the other topic.

Thanks in advance for your cooperation.

9

I would very strongly recommend you use a 3.3V Arduino.

I have tried to use 'proper' logic level converters for 5V Arduinos and the results were very marginal. It worked, just, on a UNO but not on a Mega.

Checking with a scope, on the UNO\LoRa combination, the SPI signals on the LoRa side looked terible, I was surprised it was working at all.

If I was trapped on Mars and the only thing I had to communicate with Earth was a 5V Arduino, a 3.3V LoRa device and a logic converter, I would still think a lot before trying to get it working.

10

Do not forget to connect OE to A, because it grounded by default ( and pulling low of OE pin disable all outputs of converter)

11

used a level converter on a UNO 5V logic to Raspberry Pi 3.3V logic UART some time ago and after a few months it killed the RPi interface

moved from 5V logic devices to 3.3V devices in commercial and industrial projects over 20years ago - these days some devices are using 1.8V logic