Fix bug in st7735r144_4bit.py. SSD1351 drivers no longer set baudrate to 20MHz: seems too fast despite datasheet.

DRIVERS.md

@@ -122,19 +122,18 @@ soft SPI may be used but hard may be faster.
  * `pinrs` An initialised output pin. Initial value should be 1.
  * `height=128` Display dimensions in pixels. Height must be 96 or 128.
  * `width=128`
- * `init_spi=spi_init` This optional arg enables flexible options in
- configuring the SPI bus. The default preserves existing behaviour: the SPI bus
- is initialised to 20MHz before each use. Other `spi.init` args are default.
- This facilitates bus sharing. Passing `False` disables this: `color_setup.py`
- must initialise the bus. Those settings will be left in place. If a callback
- function is passed, it will be called prior to each SPI bus write: this is for
- shared  bus applications where a non-standard `init` is required. The callback
- will receive a single arg being the SPI bus instance. In normal use it will be
- a one-liner or lambda initialising the bus. The default is this function:
+ * `init_spi=False` This optional arg enables flexible options in configuring
+ the SPI bus. The default assumes exclusive access to the bus with
+ `color_setup.py` initialising it. Those settings will be left in place. If a
+ callback function is passed, it will be called prior to each SPI bus write:
+ this is for shared  bus applications. The callback will receive a single arg
+ being the SPI bus instance. In normal use it will be a one-liner or lambda
+ initialising the bus. A minimal example is this function:
 ```python
 def spi_init(spi):
     spi.init(baudrate=20_000_000)  # Data sheet: should support 20MHz
 ```
+Despite the datasheet I failed to get this baudrate to work even on a PCB.
 
 #### A "gotcha" in the datasheet
 

color_setup/esp32_setup.py

@@ -3,31 +3,41 @@
 # Released under the MIT License (MIT). See LICENSE.
 # Copyright (c) 2020 Peter Hinch
 
-# As written, supports:
+# Pin nos. match my PCB for all displays.
+
+# As written with commented-out lines, supports:
 # Adafruit 1.5" 128*128 OLED display: https://www.adafruit.com/product/1431
 # Adafruit 1.27" 128*96 display https://www.adafruit.com/product/1673
+# Adfruit 1.8" 128*160 Color TFT LCD display https://www.adafruit.com/product/358
+# Adfruit 1.44" 128*128 Color TFT LCD display https://www.adafruit.com/product/2088
 # Edit the driver import for other displays.
 
 # WIRING (Adafruit pin nos and names).
 # ESP   SSD
 # 3v3   Vin (10)
 # Gnd   Gnd (11)
-# IO25  DC (3 DC)
-# IO26  CS (5 OC OLEDCS)
-# IO27  Rst (4 R RESET)
+# IO27  DC (3 DC)
+# IO25  CS (5 OC OLEDCS)
+# IO26  Rst (4 R RESET)
 # IO14  CLK (2 CL SCK)  Hardware SPI1
 # IO13  DATA (1 SI MOSI)
 
 from machine import SPI, Pin
 import gc
-from drivers.ssd1351.ssd1351_generic import SSD1351 as SSD
+#from drivers.ssd1351.ssd1351_generic import SSD1351 as SSD
+#from drivers.st7735r.st7735r import ST7735R as SSD
+#from drivers.st7735r.st7735r144 import ST7735R as SSD
+from drivers.st7735r.st7735r_4bit import ST7735R as SSD
 
-height = 128   # Ensure height is correct (96/128)
+height = 96   # SSD1351: ensure height is correct (96/128)
 
-pdc = Pin(25, Pin.OUT, value=0)  # Arbitrary pins
-pcs = Pin(26, Pin.OUT, value=1)
-prst = Pin(27, Pin.OUT, value=1)
-# Hardware SPI on native pins for performance
-spi = SPI(1, 10_000_000, sck=Pin(14), mosi=Pin(13), miso=Pin(12), init_spi=False)
+pdc = Pin(27, Pin.OUT, value=0)  # Arbitrary pins
+pcs = Pin(25, Pin.OUT, value=1)
+prst = Pin(26, Pin.OUT, value=1)
+# Hardware SPI on native pins for performance. Check DRIVERS.md for optimum baudrate.
+spi = SPI(1, 10_000_000, sck=Pin(14), mosi=Pin(13), miso=Pin(12))
 gc.collect()
-ssd = SSD(spi, pcs, pdc, prst, height=height)
+# ssd = SSD(spi, pcs, pdc, prst, height=height)  # Must specify height for SSD1351
+ssd = SSD(spi, pcs, pdc, prst)  # The other Adafruit displays use defaults
+# On st7735r 1.8 inch display can exchange height and width for portrait mode. See docs.
+# The 1.44 inch display is symmetrical so this doesn't apply.

drivers/ssd1351/ssd1351.py

@@ -17,11 +17,6 @@ import gc
 import micropython
 from uctypes import addressof
 
-# ESP32 produces 20MHz, Pyboard D SF2W: 15MHz, SF6W: 18MHz, Pyboard 1.1: 10.5MHz
-# OLED datasheet:  should support 20MHz
-def spi_init(spi):
-    spi.init(baudrate=20_000_000)
-
 # Timings with standard emitter
 # 1.86ms * 128 lines = 240ms. copy dominates: show() took 272ms
 # Buffer transfer time = 272-240 = 32ms which accords with expected:
@@ -85,7 +80,7 @@ class SSD1351(framebuf.FrameBuffer):
     def rgb(r, g, b):
         return (r & 0xe0) | ((g >> 3) & 0x1c) | (b >> 6)
 
-    def __init__(self, spi, pincs, pindc, pinrs, height=128, width=128, init_spi=spi_init):
+    def __init__(self, spi, pincs, pindc, pinrs, height=128, width=128, init_spi=False):
         if height not in (96, 128):
             raise ValueError('Unsupported height {}'.format(height))
         self.spi = spi

drivers/ssd1351/ssd1351_16bit.py

@@ -20,11 +20,6 @@ from uctypes import addressof
 # The ESP32 does not work reliably in SPI mode 1,1. Waveforms look correct.
 # Now using 0,0 on STM and ESP32
 
-# ESP32 produces 20MHz, Pyboard D SF2W: 15MHz, SF6W: 18MHz, Pyboard 1.1: 10.5MHz
-# OLED datasheet:  should support 20MHz
-def spi_init(spi):
-    spi.init(baudrate=20_000_000)  # Data sheet: should support 20MHz
-
 # Initialisation commands in cmd_init:
 # 0xfd, 0x12, 0xfd, 0xb1,  # Unlock command mode
 # 0xae,  # display off (sleep mode)
@@ -54,7 +49,7 @@ class SSD1351(framebuf.FrameBuffer):
     def rgb(r, g, b):
         return ((r & 0xf8) << 5) | ((g & 0x1c) << 11) | (b & 0xf8) | ((g & 0xe0) >> 5)
 
-    def __init__(self, spi, pincs, pindc, pinrs, height=128, width=128, init_spi=spi_init):
+    def __init__(self, spi, pincs, pindc, pinrs, height=128, width=128, init_spi=False):
         if height not in (96, 128):
             raise ValueError('Unsupported height {}'.format(height))
         self.spi = spi

drivers/ssd1351/ssd1351_4bit.py

@@ -77,7 +77,7 @@ class SSD1351(framebuf.FrameBuffer):
     def rgb(r, g, b):
         return (r & 0xf8) << 5 | (g & 0x1c) << 11 | (g & 0xe0) >> 5 | (b & 0xf8)
 
-    def __init__(self, spi, pincs, pindc, pinrs, height=128, width=128, init_spi=spi_init):
+    def __init__(self, spi, pincs, pindc, pinrs, height=128, width=128, init_spi=False):
         if height not in (96, 128):
             raise ValueError('Unsupported height {}'.format(height))
         self.spi = spi

drivers/ssd1351/ssd1351_generic.py

@@ -23,11 +23,6 @@ import sys
 # The ESP32 does not work reliably in SPI mode 1,1. Waveforms look correct.
 # Now using 0,0 on STM and ESP32
 
-# ESP32 produces 20MHz, Pyboard D SF2W: 15MHz, SF6W: 18MHz, Pyboard 1.1: 10.5MHz
-# OLED datasheet:  should support 20MHz
-def spi_init(spi):
-    spi.init(baudrate=20_000_000)  # Data sheet: should support 20MHz
-
 # Timings with standard emitter
 # 1.86ms * 128 lines = 240ms. copy dominates: show() took 272ms
 # Buffer transfer time = 272-240 = 32ms which accords with expected:
@@ -72,7 +67,7 @@ class SSD1351(framebuf.FrameBuffer):
     def rgb(r, g, b):
         return (r & 0xe0) | ((g >> 3) & 0x1c) | (b >> 6)
 
-    def __init__(self, spi, pincs, pindc, pinrs, height=128, width=128, init_spi=spi_init):
+    def __init__(self, spi, pincs, pindc, pinrs, height=128, width=128, init_spi=False):
         if height not in (96, 128):
             raise ValueError('Unsupported height {}'.format(height))
         self.spi = spi

drivers/st7735r/st7735r144_4bit.py

@@ -49,7 +49,7 @@ class ST7735R(framebuf.FrameBuffer):
     # Same mapping in linebuf so LS byte is shifted out 1st
     @staticmethod
     def rgb(r, g, b):
-        return (b & 0xf8) << 5 | (g & 0x1c) << 11 | (g & 0xe0) >> 5 | (r & 0xf8)
+        return (r & 0xf8) << 5 | (g & 0x1c) << 11 | (g & 0xe0) >> 5 | (b & 0xf8)
 
     # rst and cs are active low, SPI is mode 0
     def __init__(self, spi, cs, dc, rst, height=128, width=128, init_spi=False):