ESP8266: LoLin V3 NodeMcu Lua WIFI Development Board

Introduction

I've got me one of this ESP8266 boards to play around with my IoT project and it turns out to be a hell of configuration when you get a clone board with no much information about the hardware itself.
Later on I saw in a online shop with the description:
"This is a new version of NodeMcu Lua WIFI Development Board
Not compatible with MAC"
... great :]

So I got this board

the only it says are the following steps:

1. Install CH340G
2. Use 9600bsp baud rate
3. Connect to wifi

Wemos.cc
LoLin new NodeMcu V3

So I went to wemos.cc navigated to the CH340G, and guess what, there is nothing in there
Since this is taking me quite a lot of time I decided to write here my findings on how to configure this undocumented breakout device configuration.

Warning!
The following steps are valid for this ESP8266 board LoLin V3 NodeMcu from wemos.cc and Macbook pro OS X Yosemite 10.10.5. I don't know if such steps are valid for any other configuration, so be carreful, if you have different configuration search for another tutorial.

Luckily I found a French blog written by Nico on September 27th, 2015

This blog describes quite similar board:
http://ouilogique.com/NodeMCU_esp8266/
and with the help of google translator i figured things out.

 

Installing CH340G for OS X

I am using OS X Yosemite 10.10.5 so installing the UART driver it is not as trivial as on Windows.
I found this driver that works for me:

http://ouilogique.com/files/2015-05-21-ch340_driver/CH34x_Install_V1.3.zip
in case the link is broken you can download it from here

Once installed you connect the board to your USB and check the port.
open the terminal and type:

ls /dev | grep tty.w

you should see one of the two serial port adaptors:

 /dev/tty.wchusbserial1410 
 /dev/tty.wchusbserial1420 

Note: The number depends on which USB port you connected the board: USB left or right
If you dont see any of these ports then you need to restart you computer. Otherwise check the USB cable, if still not working then someting went wrong with the driver installation.

Installing Esptool

Esptool is a python script that helps you to interface with your ESP8366 over the USB port.
To install python tools do:
Go to your temporal folder or any other folder where you can download the installation source, then

git clone https://github.com/themadinventor/esptool.git
cd esptool
sudo python setup.py install
which esptool.py # ⇒ /usr/local/bin/esptool.py 

The last command "which" it is to check where the script was installed.

First commands with esptool

Now let's try if the ESP8266 works. Open your console and type:

esptool.py -h

you will see the help page for esptool and how to use it.
Let's check the mac address of the ESP8266:

esptool.py -p /dev/cu.wchusbserial1410 read_mac

Notice that the command requires the port name, with the format: 

esptool.py -p <PORT_ID> read_mac

remember that you may have the other name /dev/cu.wchusbserial1420

Then the result of our querry is, in my case:
esptool.py v2.1
Connecting....
Detecting chip type... ESP8266
Chip is ESP8266
Uploading stub...
Running stub...
Stub running...
MAC: 5c:cf:7f:XX:XX:XX
Hard resetting...

Where 'X' is a Hexadecimal numer.

you can also try to read the chip id with the command:

esptool.py --port /dev/tty.wchusbserial1420 --after no_reset chip_id

or the flash size which it is important to know if you want to upgrade the NodeMcu version

esptool.py --port /dev/tty.wchusbserial1420 --after no_reset flash_id
esptool.py v2.1
Connecting....
Detecting chip type... ESP8266
Chip is ESP8266
Uploading stub...
Running stub...
Stub running...
Manufacturer: ef
Device: 4016
Detected flash size: 4MB
Staying in bootloader.

I have tried ESPlorer, which is a Java application to communicate with the ESPXX but for me does not work. I can open the port but I do not receive any answers from the ESP8266, You can have a try if you want:

http://esp8266.ru/esplorer/

You can also check the flash id in order to find more information about the chip.

esptool.py -p /dev/cu.wchusbserial1420 flash_id 
esptool.py v2.1
Connecting....
Detecting chip type... ESP8266
Chip is ESP8266
Uploading stub...
Running stub...
Stub running...
Manufacturer: ef
Device: 4016
Detected flash size: 4MB
Hard resetting...

now, with the manufacturer "ef" you can search on the following file the id of the corresponding manufactures.
 
https://code.coreboot.org/p/flashrom/source/tree/HEAD/trunk/flashchips.h

in my case "ef" refers to:

W25X chips are SPI, first byte of device ID is memory type, second
byte of device ID is related to log(bitsize)
 
#define WINBOND_NEX_ID␉0xEF␉/* Winbond (ex Nexcom) serial flashes */

Buildting your frimware on the cloud
Here you can customize the firmware your want for your board and the you will receive a email with the link for downloading it.

https://nodemcu-build.com/

Flashing the firmware

I followed the steps from the following link and it worked just fine

http://nodemcu.readthedocs.io/en/master/en/flash/

esptool.py --port /dev/tty.wchusbserial1420 write_flash --flash_mode dio 0x00000 nodemcu-master-9-modules-2017-10-08-17-51-52-integer.bin
 
esptool.py v2.1
Connecting....
Detecting chip type... ESP8266
Chip is ESP8266
Uploading stub...
Running stub...
Stub running...
Configuring flash size...
Auto-detected Flash size: 4MB
Flash params set to 0x0240
Compressed 405760 bytes to 262269...
Wrote 405760 bytes (262269 compressed) at 0x00000000 in 23.5 seconds (effective 137.9 kbit/s)...
Hash of data verified.

Leaving...
Hard resetting... 

Flash mode is dio because my board is a >=4 MByte modules. This is explained in the tool overview. The address is 0x0 because I am using the full firmware bin package (see ref) and I dont need to set the board in bootloader mode because since I am using USB direct connection this is done by the tool (see ref)