Differences

This shows you the differences between two versions of the page.

--- using_pico_with_ssd1306_based_lcd_and_spi [2026/08/21 13:22] – [Python Code] walkeradmin
+++ using_pico_with_ssd1306_based_lcd_and_spi [2026/08/24 20:01] (current) – [Python Code] walkeradmin
@@ Line 1: / Line 1: @@
 ====== Using Pico with SSD1306 based LCD and SPI ======
-<color #ed1c24>***** THIS PAGE IS WORK IN PROGRESS *****</color>
-\\
 <color #db5f0b>Aug 2026</color>
 \\
@@ Line 48: / Line 46: @@
 \\
 \\
-{{ :i2c-vs-spi.png?400 |}}
+{{ :i2c-vs-spi.png?600 |}}
 \\
+So SPI is faster, but there is no addressing, so you cannot chain multiple SPI devices from a single set of Pico GPIO Pins. If you need to run multiple displays, your choice is to either use I2C LCDs, or use multiple sets of SPI pins for each LCD.
+\\
+\\
+----
+==== The Driver for SPI (1306 driver chip) ====
+\\
+Below is the driver you will need for the LCD. You need to put it in to the <color #ed1c24>lib</color> folder on your Pico.
+<code:python | download>
+from machine import Pin, SPI
+from ssd1306_spi import SSD1306_SPI
+import time
+# SPI1 setup
+spi = SPI(1, baudrate=8000000, polarity=0, phase=0)
+dc  = Pin(13, Pin.OUT)
+res = Pin(12, Pin.OUT)
+cs  = Pin(14, Pin.OUT)
+oled = SSD1306_SPI(128, 64, spi, dc, res, cs)
+oled.fill(0)
+oled.text("Hello Alan!", 0, 0)
+oled.text("SSD1306 SPI OK", 0, 16)
+oled.text("Pico 2 Ready", 0, 32)
+oled.show()
+# call the function below from your main code with the value 255 (max  brightness)
+oled.set_brightness(255)
+</code>
+\\
+\\
+----
+==== LCD Test Code ----
+\\
+I want to look at the old I2C code and compare to the SPI code to point out some differences, this is the Python code that just prints 8 static lines on the LCD for a simple test.
+\\
+\\
+Here is the original I2C code
+<code:python | download>
+from machine import Pin, I2C    #Gives access to the I²C Pins. Without it, you couldn’t use GPIO pins or I²C.
+import ssd1306
+import time
+i2c = I2C(0, scl=Pin(5), sda=Pin(4), freq=200000)
+lcd = ssd1306.SSD1306_I2C(128, 64, i2c)
+lcd.fill(0)
+lcd.text("Yo Tuesday Club!", 0, 0)
+lcd.text("SSD1306 LCD",      0, 8)
+lcd.text("Address 0x3C",     0, 16)
+lcd.text("Cool :)",          0, 24)
+lcd.text("Another Line :)",  0, 32)
+lcd.text("One More? :)",     0, 40)
+lcd.text("Line 7",           0, 48)
+lcd.text("Line 8",           0, 56)
+lcd.show()
+time.sleep(300)
+lcd.fill(0)
+lcd.show()
+</code>
+Here is the same code, but modified to run the SPI LCD Screen.
+\\
+<color #ed1c24>Use this code for your SPI LCD Display.</color>
+<code:python | download>
+from machine import Pin, SPI    #Gives access to the SPI Pins. Without it, you couldn’t use GPIO pins or SPI.
+from ssd1306_spi import SSD1306_SPI
+import time
+spi = SPI(1, baudrate=8000000, polarity=0, phase=0)
+dc  = Pin(13, Pin.OUT)
+res = Pin(12, Pin.OUT)
+cs  = Pin(14, Pin.OUT)
+oled = SSD1306_SPI(128, 64, spi, dc, res, cs)
+oled.fill(0)
+oled.text("Yo Tuesday Club!", 0, 0)
+oled.text("SSD1306 oled",      0, 8)
+oled.text("Address 0x3C",     0, 16)
+oled.text("Cool :)",          0, 24)
+oled.text("Another Line :)",  0, 32)
+oled.text("One More? :)",     0, 40)
+oled.text("Line 7",           0, 48)
+oled.text("Line 8",           0, 56)
+oled.show()
+time.sleep(300)
+oled.fill(0)
+oled.show()
+</code>
+The second line of each Python script loads some code, there is some difference in how they work:
+  * **import ssd1306** - Loads the entire module, and you have access to all classes within that module.
+  * **from ssd1306_spi import SSD1306_SPI** - Loads just the SSD1306_SPI class from the module ssd1306_spi.
+  * **In the first example we used the name lcd** - lcd = ssd1306.SSD1306_I2C(128, 64, i2c)
+  * **In the second example we used the name oled** - oled = SSD1306_SPI(128, 64, spi, dc, res, cs)
+The rest is pretty much the same, from a code perspective there really isn't much difference in the amount of work to get the I2C or SPI LCD displays working.
+\\
+\\
+----
+==== The Running LCDs ====
+\\
+Below we can see both the I2C LCD (on the right) and the SPI LCD (Below the Pico).
+\\
+\\
+{{ :0.96-spi-lcd-running.jpeg?500 |}}
+\\
+They both work really well and for simple text based applications will be perfect.
+\\
+\\
+----