Communication between laptop and KL25Z via WiFi using ESP8266 (ESP-01)

ElectroDesi9n — Fri, 13 Dec 2024 17:31:25 GMT

I want my laptop to communicate with KL25Z via wifi and ESP8266 is the bridge. my laptop sends information to ESP-01 via wifi and then the ESP-01 sends those data to KL25Z via cable (the reverse direction will work as well, from KL25Z to ESP-01 and to laptop). The communication protocol is UART.

To implement this project, I connected my KL25Z to laptop with its own cable. ESP-01 and KL25Z are connected with jumper wires as:

KL25Z 3.3 V --> ESP-01 VCC

KL25Z 3.3 V --> ESP-01 CH_PD

KL25Z GND --> ESP-01 GND

KL25Z TX --> ESP-01 RX

KL25Z RX --> ESP-01 TX

My problem is to program these boards. It's said we can prgram ESP-01 with USB-to-serial driver or external MCU (which in my case is KL25Z). I'd appreciate your help if you answer following question:

1- Is my connections correct now?

2- How should I program ESP-01 using my KL25Z board? should I first configure the UART between laptop and KL25Z, and configure ESP-01 using that path?

3- Also, can someone explain what does RST, GPIO0 and GPIO2 do? Different websites tell different things and all of those are old. My ESP-01 is new and I want to know pulling these pins high and low will do what.

Re: Communication between laptop and KL25Z via WiFi using ESP8266 (ESP-01)

xiangjun_rong — Mon, 16 Dec 2024 03:21:23 GMT

Hi,

This is the EPS8266-01 board.

First of all, I suggest you contact support engineer of ESP8266-01 board for the connection.

For your connection:

KL25Z 3.3 V --> ESP-01 VCC

KL25Z 3.3 V --> ESP-01 CH_PD

KL25Z GND --> ESP-01 GND

KL25Z TX --> ESP-01 RX

KL25Z RX --> ESP-01 TX

It appears that the GPIO0 should be connected to 3.3V.

Regarding the connection between FRDM-KL25Z, it is okay to just connect the uart TXD/RXD to the above board.

Pls download SDK package of FRDM-Kl25Z.

https://mcuxpresso.nxp.com/en

Hope it can help you

XiangJun Rong

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Communication between laptop and KL25Z via WiFi using ESP8266 (ESP-01)

Re: Communication between laptop and KL25Z via WiFi using ESP8266 (ESP-01)