Arduino UNO + ESP8266 ESP-12E

Projects Networking, Protocols, and Devices
1

Hello,

I wanted to get my arduino into my WiFi Network.
So i ordered the ESP8266 Wifi Module.

But it seems like I ordered something wrong? I only can find tutorials how to program this
chip? It is possible to connect with Arduino to get my Arduino into my WiFi?

In every tutorial they talk about a "ch_pd" Pin but my Module don't have this Pin.

Specifications:

Pins:

SCLK MOSI GPIO10 GPIO09 MISO CS0
TKD0 RST
RXD0 ADC
GPIO5 EN
GPIO4 GPI16
GPIO0 GPIO14
GPIO2 GPIO12
GPIO15 GPIO13
GND VCC

2

mathishuettl:
I only can find tutorials how to program this
chip? It is possible to connect with Arduino to get my Arduino into my WiFi?

That's because it's much easier to program it directly, than to program the Arduino to tell the ESP what to do using AT commands.
Depending on your project, you might not need the UNO at all, this will make things much easier.
The ESP is actually a much more capable microcontroller that an Arduino UNO (5 to 10 times the clock speed, 40 times more RAM, 4MB of flash storage ... ). If you use AT commands, you mostly waste those resources.

There are three main possibilities here:

  1. Connect the ESP8266 to a UARTs on the UNO (Hardware or Software), upload a program to the UNO, and communicate with the ESP using AT commands. All code is executed on the UNO, the ESP just follows the UNO's commands.

  2. Program the ESP8266, and program the UNO (separately). The ESP program should handle all WiFi related stuff, like establishing a connection, connecting to a server, creating HTTP requests, parsing the server's response ... And send the useful data to the UNO. If you need to send something to a server, the UNO just sends it to the ESP first, and the ESP connects to the server, creates an HTTP request containing the data, and handles the response.
    In a sense, this is similar to using AT commands, but you have much more control over what's happening, and you can use the ESP's resources for parsing data etc. This can be a heavy task for an UNO alone.

  3. This one is only an option if the ESP8266 has enough I/O pins for your project (keep in mind that you could use I/O expanders or multiplexing if necessary). The ESP8266 has 11 I/O pins, and that's enough for most small projects.
    In this scenario, you forget about the UNO entirely, and you just use the ESP like any normal Arduino.
    It can do pretty much anything an Arduino can do, but sometimes it's just a matter of finding the right libraries for your hardware.
    This is by far the easiest and cleanest solution of the three.

If you decide to go with option 2 or 3, this guide will definitely get you started, and it contains some very useful information even if you want to use AT commands (things like the TCP/IP stack, how the internet works, HTTP requests ...).

mathishuettl:
In every tutorial they talk about a "ch_pd" Pin but my Module don't have this Pin.

CH_PD should have a dash above it, because it is active low. In other words the "Chip Powerdown" is active when CH_PD is low (connected to ground). Or: the chip is enabled when CH_PD is connected to Vcc (3.3V). In other words, it's the same as an "enable" pin, and that's what it's called on your module: "EN".

Pieter

1 Like
3

more options

  • with SDK AT commands firmware in the ESP use WiFiEsp library in the UNO

  • use some other firmware like esp-link or WiFi Link in ESP and corresponding library on UNO side

WiFi Link firmware is a sketch for the esp8266. it is easy to modifying it and (OTA) uploading.