Make display update faster by sending all page address and data in one...

Make display update faster by sending all page address and data in one transfer and prepare DMA for future use

lib/cube/sh1106.py

@@ -30,10 +30,17 @@
 
 
 from micropython import const
+import machine
+import rp2
 from math import sin, cos
 import utime as time
 import framebuf
 
+_WRITE_SIZE = const(135)
+_I2C1_BASE = const(0x40048000)
+_IC_TAR = const(_I2C1_BASE + 0x04)  # Offset 0x04
+_IC_ENABLE = const(_I2C1_BASE + 0x6C)  # _IC_ENABLE register address
+DMA = False
 
 # Register definitions
 _SET_CONTRAST        = const(0x81)
@@ -69,6 +76,8 @@ class SH1106(framebuf.FrameBuffer):
         self.bufsize = self.pages * self.width
         self.renderbuf = bytearray(self.bufsize)
         self.pages_to_update = 0
+        
+        self.init_memoryview()
 
         if self.rotate90:
             self.displaybuf = bytearray(self.bufsize)
@@ -94,10 +103,22 @@ class SH1106(framebuf.FrameBuffer):
         self.pry = 0
         self.data_points = 0 #no of data points in continuous chart
 
+    def init_memoryview(self):
+        buffer = bytearray(_WRITE_SIZE*2) 
+        self.disp_send_memoryview = memoryview(buffer)
+        self.disp_send_memoryview[1] = 0x04
+        self.disp_send_memoryview[_WRITE_SIZE*2-1] =0x02
+        self.disp_send_memoryview[0] = 0x80
+        # self.disp_send_memoryview[2] page address
+        self.disp_send_memoryview[4] = 0x80
+        self.disp_send_memoryview[6] = 0x02
+        self.disp_send_memoryview[8] = 0x80
+        self.disp_send_memoryview[10] = 0x10
+        self.disp_send_memoryview[12] = 0x40
+
     def init_display(self):
         self.reset()
-        self.fill(0)
-        self.show()
+        self.fill(1)
         self.poweron()
         # rotate90 requires a call to flip() for setting up.
         self.flip(self.flip_en)
@@ -140,13 +161,9 @@ class SH1106(framebuf.FrameBuffer):
             pages_to_update = (1 << self.pages) - 1
         else:
             pages_to_update = self.pages_to_update
-        #print("Updating pages: {:08b}".format(pages_to_update))
         for page in range(self.pages):
             if (pages_to_update & (1 << page)):
-                self.write_cmd(_SET_PAGE_ADDRESS | page)
-                self.write_cmd(_LOW_COLUMN_ADDRESS | 2)
-                self.write_cmd(_HIGH_COLUMN_ADDRESS | 0)
-                self.write_data(db[(w*page):(w*page+w)])
+                self.write_at_once(page, db[(w*page):(w*page+w)])
         self.pages_to_update = 0
 
     def register_updates(self, y0, y1=None):
@@ -524,6 +541,14 @@ class SH1106_I2C(SH1106):
         self.temp = bytearray(2)
         if res is not None:
             res.init(res.OUT, value=1)
+        self.dma = rp2.DMA()
+        self.dma_config = self.dma.pack_ctrl(size=0, inc_write=False)
+        self.dma_buffer = bytearray(1)
+        self.dma_ctrl = self.dma.pack_ctrl(
+            size=1,
+            inc_read=True,
+            inc_write=False,
+            treq_sel=34)
         super().__init__(width, height, external_vcc, rotate)
 
     def write_cmd(self, cmd):
@@ -536,6 +561,21 @@ class SH1106_I2C(SH1106):
         with self.i2c_lock:
             self.i2c.writeto(self.addr, b'\x40'+buf)
 
+    def write_at_once(self, page, buf):
+        with self.i2c_lock:
+            if DMA:
+                self.disp_send_memoryview[2] = (_SET_PAGE_ADDRESS | page)
+                for i in range(len(buf)):
+                    self.disp_send_memoryview[14+i*2] = buf[i]
+                machine.mem32[_IC_ENABLE] = 0  # Disable I2C0
+                machine.mem32[_IC_TAR] = self.addr
+                machine.mem32[_IC_ENABLE] = 1  # Disable I2C0
+                self.dma.config(read=self.disp_send_memoryview,write=self.i2c ,count=_WRITE_SIZE,ctrl=self.dma_ctrl,trigger=True)
+                while self.dma.active():
+                    continue
+            else:
+                self.i2c.writeto(self.addr, b'\x80'+(_SET_PAGE_ADDRESS | page).to_bytes(1, 'little')+b'\x80\x02'+b'\x80\x10'+b'\x40'+buf)
+
     def reset(self):
         super().reset(self.res)