updating content

docs/lessons/13-real-time-clocks.md

@@ -422,3 +422,42 @@ Unless you need absolute minimal components, stick with the DS3231 for better ac
 
 The internal RTC example on the [MicroPython RP2](https://docs.micropython.org/en/latest/rp2/quickref.html#real-time-clock-rtc) site would work functionally, but would need resetting after each power cycle.
 
+## Reading the Temperature from the DS3231 Real Time Clock
+
+The math of reading the temperature from the DS3231 is unfortunately rather complicated.  Here are the steps
+
+1. Strip off the sign bit by doing a Boolean AND with 0x7f
+2. If the MSB is set we need to make the temperature negative
+3. Then we add the fraction from the LSB
+4. Finally, we convert the temperature in C to F
+
+```python
+def read_temperature():
+    """Read temperature from DS3231 RTC."""
+    # Read temperature registers
+    i2c.writeto(DS3231_ADDR, b'\x11')
+    temp_data = i2c.readfrom(DS3231_ADDR, 2)
+    temp_msb = temp_data[0]
+    temp_lsb = temp_data[1]
+
+    # Get raw temp value (ignoring sign bit)
+    raw_temp = temp_msb & 0x7F  # Strip off sign bit
+
+    # 0xD7 & 0x7F = 0x57 = 87 decimal (original value minus sign bit)
+    # If sign bit was set, make it negative
+    if temp_msb & 0x80:
+        raw_temp = raw_temp ^ 0x7F  # Invert the bits
+        raw_temp = -(raw_temp + 1)  # Two's complement
+
+    # Add fraction from LSB
+    frac = (temp_lsb >> 6) * 0.25
+    temp_c = raw_temp + frac
+
+    # Convert to Fahrenheit
+    temp_f = (temp_c * 9.0 / 5.0) + 32.0
+
+    print(f"Raw temp (after sign bit removal): {raw_temp}")
+    print(f"Temperature: {temp_c}°C = {temp_f}°F")
+
+    return temp_f
+```

docs/setup/06-pico-w-setup.md

@@ -0,0 +1,15 @@
+# Pico W Setup
+
+When installing the Pico "W" (Wireless), you will need to download
+a different version of the MicroPython runtime.
+
+The list of runtime images is on the
+[https://micropython.org/download/RPI_PICO_W](https://micropython.org/download/RPI_PICO_W/) page.
+
+In this example, we are using [v1.24.1 (2024-11-29) .uf2](https://github.com/micropython/micropython/releases/tag/v1.24.1).
+
+Here is the image from Thonny that shows
+what version you are using.  Note that you MUST select BOTSEL button
+before Thonny will download the new MicroPython runtime.
+
+![Pico W Thonny Setup for MicroPython 1.24.1](./06-thonny-pico-w-setup.png)

src/kits/large-oled-w/10-test-rtc.py

@@ -0,0 +1,66 @@
+from machine import I2C, Pin
+import time
+
+# I2C setup
+i2c = I2C(0, sda=Pin(0), scl=Pin(1))
+
+# Device addresses
+RTC_ADDR = 0x68  # Both DS1307 and DS3231 use 0x68
+
+def identify_rtc():
+    """
+    Identify whether the RTC is a DS1307 or DS3231
+    Returns: String identifying the RTC type
+    """
+    try:
+        # Try to read the status register (0x0F) - only exists on DS3231
+        i2c.writeto(RTC_ADDR, b'\x0F')
+        status = i2c.readfrom(RTC_ADDR, 1)[0]
+
+        # Try to read control register (0x0E) - only exists on DS3231
+        i2c.writeto(RTC_ADDR, b'\x0E')
+        control = i2c.readfrom(RTC_ADDR, 1)[0]
+
+        # If we got here, it's almost certainly a DS3231
+        # Try reading temperature registers as final confirmation
+        i2c.writeto(RTC_ADDR, b'\x11')
+        temp_data = i2c.readfrom(RTC_ADDR, 2)
+
+        return "DS3231 (Temperature-compensated RTC)"
+
+    except Exception as e:
+        # If we couldn't read those registers, it's probably a DS1307
+        # Let's verify by trying to read the control register (0x07) of DS1307
+        try:
+            i2c.writeto(RTC_ADDR, b'\x07')
+            control = i2c.readfrom(RTC_ADDR, 1)[0]
+            return "DS1307 (Basic RTC)"
+        except:
+            return "Unknown RTC device"
+
+def main():
+    print("\nRTC Model Identifier")
+    print("-" * 40)
+
+    # First check if any device is present at RTC address
+    devices = i2c.scan()
+    if RTC_ADDR not in devices:
+        print(f"No RTC found at address 0x{RTC_ADDR:02X}")
+        return
+
+    # Identify the RTC
+    rtc_type = identify_rtc()
+    print(f"Found: {rtc_type}")
+
+    if "DS3231" in rtc_type:
+        # Read temperature for DS3231
+        i2c.writeto(RTC_ADDR, b'\x11')
+        temp_data = i2c.readfrom(RTC_ADDR, 2)
+        temp_msb = temp_data[0]
+        temp_lsb = (temp_data[1] >> 6) * 25  # 0.25°C precision
+        temp_c = temp_msb + (temp_lsb / 100.0)
+        temp_f = (temp_c * 9/5) + 32
+        print(f"Temperature: {temp_c:.2f}°C ({temp_f:.2f}°F)")
+
+if __name__ == "__main__":
+    main()

src/kits/large-oled-w/lib/ssd1306.py

@@ -0,0 +1,159 @@
+# MicroPython SSD1306 OLED driver, I2C and SPI interfaces
+
+from micropython import const
+import framebuf
+
+
+# register definitions
+SET_CONTRAST = const(0x81)
+SET_ENTIRE_ON = const(0xA4)
+SET_NORM_INV = const(0xA6)
+SET_DISP = const(0xAE)
+SET_MEM_ADDR = const(0x20)
+SET_COL_ADDR = const(0x21)
+SET_PAGE_ADDR = const(0x22)
+SET_DISP_START_LINE = const(0x40)
+SET_SEG_REMAP = const(0xA0)
+SET_MUX_RATIO = const(0xA8)
+SET_COM_OUT_DIR = const(0xC0)
+SET_DISP_OFFSET = const(0xD3)
+SET_COM_PIN_CFG = const(0xDA)
+SET_DISP_CLK_DIV = const(0xD5)
+SET_PRECHARGE = const(0xD9)
+SET_VCOM_DESEL = const(0xDB)
+SET_CHARGE_PUMP = const(0x8D)
+
+# Subclassing FrameBuffer provides support for graphics primitives
+# http://docs.micropython.org/en/latest/pyboard/library/framebuf.html
+class SSD1306(framebuf.FrameBuffer):
+    def __init__(self, width, height, external_vcc):
+        self.width = width
+        self.height = height
+        self.external_vcc = external_vcc
+        self.pages = self.height // 8
+        self.buffer = bytearray(self.pages * self.width)
+        super().__init__(self.buffer, self.width, self.height, framebuf.MONO_VLSB)
+        self.init_display()
+
+    def init_display(self):
+        for cmd in (
+            SET_DISP,  # display off
+            # address setting
+            SET_MEM_ADDR,
+            0x00,  # horizontal
+            # resolution and layout
+            SET_DISP_START_LINE,  # start at line 0
+            SET_SEG_REMAP | 0x01,  # column addr 127 mapped to SEG0
+            SET_MUX_RATIO,
+            self.height - 1,
+            SET_COM_OUT_DIR | 0x08,  # scan from COM[N] to COM0
+            SET_DISP_OFFSET,
+            0x00,
+            SET_COM_PIN_CFG,
+            0x02 if self.width > 2 * self.height else 0x12,
+            # timing and driving scheme
+            SET_DISP_CLK_DIV,
+            0x80,
+            SET_PRECHARGE,
+            0x22 if self.external_vcc else 0xF1,
+            SET_VCOM_DESEL,
+            0x30,  # 0.83*Vcc
+            # display
+            SET_CONTRAST,
+            0xFF,  # maximum
+            SET_ENTIRE_ON,  # output follows RAM contents
+            SET_NORM_INV,  # not inverted
+            # charge pump
+            SET_CHARGE_PUMP,
+            0x10 if self.external_vcc else 0x14,
+            SET_DISP | 0x01,  # display on
+        ):  # on
+            self.write_cmd(cmd)
+        self.fill(0)
+        self.show()
+
+    def poweroff(self):
+        self.write_cmd(SET_DISP)
+
+    def poweron(self):
+        self.write_cmd(SET_DISP | 0x01)
+
+    def contrast(self, contrast):
+        self.write_cmd(SET_CONTRAST)
+        self.write_cmd(contrast)
+
+    def invert(self, invert):
+        self.write_cmd(SET_NORM_INV | (invert & 1))
+
+    def rotate(self, rotate):
+        self.write_cmd(SET_COM_OUT_DIR | ((rotate & 1) << 3))
+        self.write_cmd(SET_SEG_REMAP | (rotate & 1))
+
+    def show(self):
+        x0 = 0
+        x1 = self.width - 1
+        if self.width == 64:
+            # displays with width of 64 pixels are shifted by 32
+            x0 += 32
+            x1 += 32
+        self.write_cmd(SET_COL_ADDR)
+        self.write_cmd(x0)
+        self.write_cmd(x1)
+        self.write_cmd(SET_PAGE_ADDR)
+        self.write_cmd(0)
+        self.write_cmd(self.pages - 1)
+        self.write_data(self.buffer)
+
+
+class SSD1306_I2C(SSD1306):
+    def __init__(self, width, height, i2c, addr=0x3C, external_vcc=False):
+        self.i2c = i2c
+        self.addr = addr
+        self.temp = bytearray(2)
+        self.write_list = [b"\x40", None]  # Co=0, D/C#=1
+        super().__init__(width, height, external_vcc)
+
+    def write_cmd(self, cmd):
+        self.temp[0] = 0x80  # Co=1, D/C#=0
+        self.temp[1] = cmd
+        self.i2c.writeto(self.addr, self.temp)
+
+    def write_data(self, buf):
+        self.write_list[1] = buf
+        self.i2c.writevto(self.addr, self.write_list)
+
+
+class SSD1306_SPI(SSD1306):
+    def __init__(self, width, height, spi, dc, res, cs, external_vcc=False):
+        self.rate = 10 * 1024 * 1024
+        dc.init(dc.OUT, value=0)
+        res.init(res.OUT, value=0)
+        cs.init(cs.OUT, value=1)
+        self.spi = spi
+        self.dc = dc
+        self.res = res
+        self.cs = cs
+        import time
+
+        self.res(1)
+        time.sleep_ms(1)
+        self.res(0)
+        time.sleep_ms(10)
+        self.res(1)
+        super().__init__(width, height, external_vcc)
+
+    def write_cmd(self, cmd):
+        self.spi.init(baudrate=self.rate, polarity=0, phase=0)
+        self.cs(1)
+        self.dc(0)
+        self.cs(0)
+        self.spi.write(bytearray([cmd]))
+        self.cs(1)
+
+    def write_data(self, buf):
+        self.spi.init(baudrate=self.rate, polarity=0, phase=0)
+        self.cs(1)
+        self.dc(1)
+        self.cs(0)
+        self.spi.write(buf)
+        self.cs(1)