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GSM module circuit with ESP32 board
Posted: Mon Feb 11, 2019 5:49 pm
by Sacp328
I am using quectal m95 gsm module with esp32 board to create a point to point cellular connection, Can i connect thier TX and RX pins directly or i need to do some volatge level conversions???
Re: GSM module circuit with ESP32 board
Posted: Tue Feb 12, 2019 7:27 am
by permal
Check the datasheets for voltage levels. ESP32 uses 3.3V so if your devices uses the same you should be good to go.
Re: GSM module circuit with ESP32 board
Posted: Tue Feb 12, 2019 8:37 am
by Sacp328
permal wrote: ↑Tue Feb 12, 2019 7:27 am
Check the datasheets for voltage levels. ESP32 uses 3.3V so if your devices uses the same you should be good to go.
my gsm module uses something around 3.9 to 4 V, what should i do.
Re: GSM module circuit with ESP32 board
Posted: Tue Feb 12, 2019 11:10 am
by permal
4V logic? Sounds like an odd value. Are you sure about that?
In any case, use a levelshifter, such as the
TXB0102DCUR.
You could also use a simple voltage divider based on two resistors for each channel.