ESP8266 Community Forum

- Thu Oct 01, 2015 6:06 am #30252 Bonjour,
Can you tell me if Adafruit 4 Channel Bi-Directional I2C Logic Level Converter can be used with a ESP8266-01 ?
In characterstics they say it can be used to link a series TTL.
I would use to power the ESP8266 and for data transmission.
Thank you a lot

- Thu Oct 01, 2015 2:09 pm #30284 Hi, I haven't used this myself but have seen various posts that have. So a reserved yes.
Dependant on what you are using as a serial to ttl device you may not even need to go that far.

ESP Tx -> ??? Rx generaly works as 3.3V is high enough to be a logic one to a 5V powered system.
ESP Rx -> ??? Tx can be dropped using 3 x 1K resistors (voltage divider).

Code: Select allConnect the 3 resistors in series.
Connect one end to both the ESP GND & your ??? device GND.
Connect the Tx of your ??? device to the other end of the resistors.
Connect the Rx of the ESP to the joint between the resistor one away from Tx and two away from GND.

Tx - resistor - Rx - resistor - resistor - GND + GND


I used this for quite some time and 1k resistors work fine up to 115k baud.

If you have a CH340 like me this mod works a treat and is all you need.

- Thu Oct 01, 2015 2:18 pm #30286

Adafruit 4 Channel Bi-Directional I2C Logic Level Converter

In fact, this small adaptor is made with 4 times the following MOSFET circuit :

Of course, it will work, but do you really need 4 channels ?

- Fri Oct 02, 2015 4:21 am #30339 Hello...

thank you very much for answers ...

Of course, it will work, but do you really need 4 channels ?

I just need 2 channels, ESP Tx -> MEGA Rx (not need ? ) and ESP Rx -> MEGA Tx
not to read an html page but transmit data as bits, String ... to another arduino with an another ESP8266 , both using WiFi

ESP Rx -> ??? Tx can be dropped using 3 x 1K resistors (voltage divider).

Code: Select allConnect the 3 resistors in series.
Connect one end to both the ESP GND & your ??? device GND.
Connect the Tx of your ??? device to the other end of the resistors.
Connect the Rx of the ESP to the joint between the resistor one away from Tx and two away from GND.

Tx - resistor - Rx - resistor - resistor - GND + GND


[/quote]

I'm inexperienced in electronics and use a voltage divider scared me from what I read on the forum ...
I would use the ESP8266 with Arduino Mega for automation/domotique testing and I found a site that seems answer my questions ...
https://hackaday.io/project/3072/instructions
I hope it'll work for me

thank you again