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What we want to achieve
Use a display with PCD8544 CMOS LCD controller/driver - e.g. Nokia 5110 LED Display - with a nodeMCU ESP8266 compatible development board and Lua.
Requirements
- nodeMCU ESP8266 compatible development board (see here)
- Display with PCD8544 controller - e.g. Nokia 5110 - (see here)
- nodeMCU firmware with the following modules included: gpio, i2c, spi, u8g2, uart
- u8g2 configuration - ensure you include your fonts. For the example here we will need the 6x10_tf and 5x8_tf font
For simplicity, you can download a suitable firmware here.
The firmware was created using the online service nodemcu-build.com
Restrictions
- This tip is focused on Lua and ESP8266
- The pin connections are guaranteed to work with our Nokia 5110 displays. Other similar displays might have a different pin layout and you will need to adapt to your specific module.
- The tip uses SPI, hence there might be conflicts if you are using other SPI modules.
How to
The u8g2 module only supports the PCD8544 controller via SPI. This means we will have to use the HMOSI and HSCLK GPIOs on the development board. For the connections, you are welcome to change the pin layout to suit your project needs.
Wiring
| PCD8544/LED | ESP8266 |
| Pin 1 - RST | D0/GPIO16 |
| Pin 2 - CE (CS) | D8/GPIO15 - pull down with 10k resistor to GND |
| Pin 3 - DC | D4/GPIO2 |
| Pin 4 - DIN | D7/HMOSI (fixed - you can't use a different pin) |
| Pin 5 - CLK | D5/HSCLK (fixed - you can't use a different pin) |
| Pin 6 - VCC | 3.3V - either from Development board or other sources |
| Pin 7 - BL | Not used in this example |
| Pin 8 - GND | GND - either from Development board or another source |
Code
--[[
Nokia 5110 LED with PCD8544
8 November 2018
Author: dante@serveronthemove.com.au
Hardware:
nodeMCU ESP8266(EX) Devkit V3
8 pin Nokia 5110 84x48 display w PCD8544
Wiring:
LED -> NodeMCU 8266
1 - RST -> D0/GPIO16
2 - CE (CS) -> D8/GPIO15 - pull down with 10K to GND
3 - DC -> D4/GPIO2
4 - DIN -> D7/HMOSI
5 - CLK -> D5/HSCLK
6 - VCC -> 3.3V
7 - BL -> Not used in this example
8 - GND -> GND
nodeMCU Firmware Build
built against the master branch and includes the following modules: file, gpio, i2c, net, node, spi, tmr, u8g2, uart, wifi, tls
u8g2 - SPI - pcd8544_84x48 module
u8g2 - fonts: 6x10_tf, 5x8)tf
--]]
-- Variables
PIN_CS = 8 -- GPIO15, pull-down 10k to GND
PIN_DC = 4 -- GPIO2
PIN_RES = 0 -- GPIO16
M_BUS = 1
-- Initialise module
spi.setup(M_BUS, spi.MASTER, spi.CPOL_LOW, spi.CPHA_LOW, 8, 8)
--gpio.mode(cs, gpio.INPUT, gpio.PULLUP)
disp = u8g2.pcd8544_84x48(M_BUS, PIN_CS, PIN_DC, PIN_RES)
disp:setFontRefHeightExtendedText()
disp:setContrast(125)
disp:setFontPosTop()
-- start
disp:clearBuffer() -- start with clean buffer
disp:setFont(u8g2.font_6x10_tf) -- set 6x10 font
disp:drawStr(1, 1, "Nokia 5110")
disp:drawStr(1, 9, "(PCD8544) test")
disp:drawStr(2, 17, "for nodeMCU")
disp:drawStr(2, 25, "by")
disp:setFont(u8g2.font_5x8_tf) -- switch to smaller font
disp:drawStr(1, 33, "ServerOnTheMove")
disp:drawStr(48, 39, ".com.au")
disp:sendBuffer() -- sent buffer to display
-- and done
