HUZZAH ESP8266 OLED

HUZZAH 8266 OLED

HUZZAH ESP8266 OLED Output

There are many OLED Led displays available for a reasonable price these days. Ebay and Amazon are prolific sellers of these devices:

Using the HUZZAH ESP8266 to output to an OLED is straightforward as the following example hopefully demonstrates:

function init_OLED(sda,scl) --Set up the u8glib lib
     sla = 0x3c
     i2c.setup(0, sda, scl, i2c.SLOW)
     disp = u8g.ssd1306_128x64_i2c(sla)
     disp:setFont(u8g.font_6x10)
     disp:setFontRefHeightExtendedText()
     disp:setDefaultForegroundColor()
     disp:setFontPosTop()
end
init_OLED(6,7) --Run setting up

--Output IP Address and MAC Address of HUZZAH ESP8266 to the OLED

disp:firstPage()
repeat
disp:drawStr(0,0,"ESP8266 Info") -- Starting on line 0
disp:drawStr(0,11*2,"IP Address:") --Output IP Address to OLED
disp:drawStr(0,11*3,wifi.sta.getip())
disp:drawStr(0,11*4,"MAC Address:") --Output MAC Address of ESP8266 to OLED
disp:drawStr(0,11*5,wifi.sta.getmac())  
until disp:nextPage() == false

HUZZAH OLED GPIO PIN Numbering

HUZZAH OLED GPIO PIN Numbering
NOTE: I'm connecting the OLED pins SCL and SDA to the pins on the HUZZAH board numbered 12 and 13 i.e.

OLED SDA Pin -> Pin number 12 on the Huzzah Board = 6 in the Lua code
OLED SCL Pin -> Pin number 13 on the Huzzah Board = 7 in the Lua code


The Lua code above then uses IO index numbers 6 and 7:


init_OLED(6,7) --Run setting up

If you look at the table below, pin 12 on the HUZZAH board corresponds to GPIO 6 in code, pin 13 on the HUZZAH board corresponds to GPIO 7 in code.


IO
   index

   

ESP8266 pin

   

IO
   index

   

ESP8266 pin

  

 


  

0
  [*]

  

GPIO16

  

7

  

GPIO13

 

  

1

  

GPIO5

  

8

  

GPIO15

 

  

2

  

GPIO4

  

9

  

GPIO3

 

  

3

  

GPIO0

  

10

  

GPIO1

 

  

4

  

GPIO2

  

11

  

GPIO9

 

  

5

  

GPIO14

  

12

  

GPIO10

 

  

6

  

GPIO12

  






Source: https://github.com/nodemcu/nodemcu-firmware/wiki/nodemcu_api_en#new_gpio_map


Display Nearby WiFi Access Points On An OLED


So, for example, to display all of the nearby WiFi Access Points on the OLED:

wifi.setmode(wifi.STATION) --Set mode to STATION so he chip can receive the SSID broadcast
function init_OLED(sda,scl) --Set up the u8glib lib
     sla = 0x3c
     i2c.setup(0, sda, scl, i2c.SLOW)
     disp = u8g.ssd1306_128x64_i2c(sla)
     disp:setFont(u8g.font_6x10)
     disp:setFontRefHeightExtendedText()
     disp:setDefaultForegroundColor()
     disp:setFontPosTop()
end
init_OLED(6,7) --Run setting up

disp:firstPage()
repeat
disp:drawStr(0,0,"ESP8266 Info") -- Starting on line 0
disp:drawStr(0,11*2,"IP Address:")
disp:drawStr(0,11*3,wifi.sta.getip())
disp:drawStr(0,11*4,"MAC Address:")
disp:drawStr(0,11*5,wifi.sta.getmac()) -- 
until disp:nextPage() == false

tmr.delay(7000000) --7 second delay

tmr.alarm(0,3000,1,function()
    wifi.sta.getap(function(t) 
         disp:firstPage()
         repeat
         disp:drawStr(0,0,"WiFi AP Search") -- Starting on line 0
            lines = 2
            for k,v in pairs(t) do
                disp:drawStr(0,lines * 11,k.." "..v:sub(3,5).."dbi")
                lines = lines + 1
            end
        until disp:nextPage() == false
    end)
end)