Merge pull request #191 from pimoroni/patch_plasma2040

Updates to Plasma 2040 C++ and MP examples

drivers/CMakeLists.txt

@@ -1,3 +1,4 @@
+add_subdirectory(analog)
 add_subdirectory(esp32spi)
 add_subdirectory(ioexpander)
 add_subdirectory(ltp305)
@@ -18,4 +19,5 @@ add_subdirectory(bme68x)
 add_subdirectory(bmp280)
 add_subdirectory(bme280)
 add_subdirectory(button)
+add_subdirectory(plasma)
 add_subdirectory(rgbled)

drivers/analog/CMakeLists.txt

@@ -0,0 +1 @@
+include(analog.cmake)

drivers/analog/analog.cmake

@@ -0,0 +1,11 @@
+set(DRIVER_NAME analog)
+add_library(${DRIVER_NAME} INTERFACE)
+
+target_sources(${DRIVER_NAME} INTERFACE
+  ${CMAKE_CURRENT_LIST_DIR}/${DRIVER_NAME}.cpp
+)
+
+target_include_directories(${DRIVER_NAME} INTERFACE ${CMAKE_CURRENT_LIST_DIR})
+
+# Pull in pico libraries that we need
+target_link_libraries(${DRIVER_NAME} INTERFACE pico_stdlib hardware_adc)

drivers/analog/analog.cpp

@@ -0,0 +1,18 @@
+#include "analog.hpp"
+
+namespace pimoroni {
+    uint16_t Analog::read_raw() {
+      return adc_read();
+    }
+
+    float Analog::read_voltage() {
+      return ((float)adc_read() * 3.3f) / (1 << 12) / amplifier_gain;
+    }
+
+    float Analog::read_current() {
+      if(resistor > 0.0f)
+        return read_voltage() / resistor;
+      else
+        return read_voltage();
+    }
+};

drivers/analog/analog.hpp

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <stdint.h>
+#include "pico/stdlib.h"
+#include "hardware/adc.h"
+#include "common/pimoroni_common.hpp"
+
+namespace pimoroni {
+
+  class Analog {
+  public:
+    Analog(uint pin, float amplifier_gain = 1.0f, float resistor = 0.0f) :
+    pin(pin), amplifier_gain(amplifier_gain), resistor(resistor) {
+      adc_init();
+
+      //Make sure GPIO is high-impedance, no pullups etc
+      adc_gpio_init(pin);
+
+      //Select ADC input 0 (GPIO26)
+      adc_select_input(pin - 26);
+    };
+    uint16_t read_raw();
+    float read_voltage();
+    float read_current();
+  private:
+    uint pin;
+    float amplifier_gain;
+    float resistor;
+  };
+
+}

drivers/plasma/CMakeLists.txt

@@ -0,0 +1 @@
+include(plasma.cmake)

drivers/plasma/plasma.cmake

@@ -0,0 +1,18 @@
+set(DRIVER_NAME plasma)
+add_library(${DRIVER_NAME} INTERFACE)
+
+target_sources(${DRIVER_NAME} INTERFACE
+  ${CMAKE_CURRENT_LIST_DIR}/apa102.cpp
+  ${CMAKE_CURRENT_LIST_DIR}/ws2812.cpp
+)
+
+target_include_directories(${DRIVER_NAME} INTERFACE ${CMAKE_CURRENT_LIST_DIR})
+
+target_link_libraries(${DRIVER_NAME} INTERFACE
+    pico_stdlib
+    hardware_pio
+    hardware_dma
+    )
+
+pico_generate_pio_header(${DRIVER_NAME} ${CMAKE_CURRENT_LIST_DIR}/apa102.pio)
+pico_generate_pio_header(${DRIVER_NAME} ${CMAKE_CURRENT_LIST_DIR}/ws2812.pio)

drivers/plasma/ws2812.hpp

@@ -29,7 +29,7 @@ namespace plasma {
         public:
             static const uint SERIAL_FREQ_400KHZ = 400000;
             static const uint SERIAL_FREQ_800KHZ = 800000;
-            static const uint DEFAULT_SERIAL_FREQ = SERIAL_FREQ_400KHZ;
+            static const uint DEFAULT_SERIAL_FREQ = SERIAL_FREQ_800KHZ;
             enum class COLOR_ORDER {
                 RGB,
                 RBG,

examples/CMakeLists.txt

@@ -33,4 +33,4 @@ add_subdirectory(pico_trackball_display)
 add_subdirectory(pico_audio)
 add_subdirectory(pico_wireless)
 
-add_subdirectory(plasma_2040)
+add_subdirectory(plasma2040)

examples/plasma2040/plasma2040_rainbow.cmake

@@ -0,0 +1,15 @@
+set(OUTPUT_NAME plasma2040_rainbow)
+add_executable(${OUTPUT_NAME} plasma2040_rainbow.cpp)
+
+target_link_libraries(${OUTPUT_NAME}
+        pico_stdlib
+        plasma2040
+        rgbled
+        button
+        analog
+        )
+
+# enable usb output
+pico_enable_stdio_usb(${OUTPUT_NAME} 1)
+
+pico_add_extra_outputs(${OUTPUT_NAME})

examples/plasma2040/plasma2040_rainbow.cpp

@@ -9,45 +9,64 @@
 #include "common/pimoroni_common.hpp"
 #include "rgbled.hpp"
 #include "button.hpp"
+#include "analog.hpp"
 
 /*
 Press "B" to speed up the LED cycling effect.
 Press "A" to slow it down again.
+Press "Boot" to reset the speed back to default.
 */
 
 using namespace pimoroni;
+using namespace plasma;
 
 // Set how many LEDs you have
 const uint N_LEDS = 30;
 
+// The speed that the LEDs will start cycling at
+const uint DEFAULT_SPEED = 10;
+
+// How many times the LEDs will be updated per second
+const uint UPDATES = 60;
+
+
 // Pick *one* LED type by uncommenting the relevant line below:
 
 // APA102-style LEDs with Data/Clock lines. AKA DotStar
-//plasma::APA102 led_strip(N_LEDS, pio0, 0, plasma::PIN_DAT, plasma::PIN_CLK);
+//APA102 led_strip(N_LEDS, pio0, 0, plasma2040::DAT, plasma2040::CLK);
 
 // WS28X-style LEDs with a single signal line. AKA NeoPixel
 // by default the WS2812 LED strip will be 400KHz, RGB with no white element
-plasma::WS2812 led_strip(N_LEDS, pio0, 0, plasma::PIN_DAT);
+WS2812 led_strip(N_LEDS, pio0, 0, plasma2040::DAT);
 
-Button button_a(plasma::BUTTON_A, Polarity::ACTIVE_LOW, 50);
-Button button_b(plasma::BUTTON_B, Polarity::ACTIVE_LOW, 50);
-RGBLED led(plasma::LED_R, plasma::LED_G, plasma::LED_B);
+Button user_sw(plasma2040::USER_SW, Polarity::ACTIVE_LOW, 0);
+Button button_a(plasma2040::BUTTON_A, Polarity::ACTIVE_LOW, 50);
+Button button_b(plasma2040::BUTTON_B, Polarity::ACTIVE_LOW, 50);
+RGBLED led(plasma2040::LED_R, plasma2040::LED_G, plasma2040::LED_B);
+Analog sense(plasma2040::CURRENT_SENSE, plasma2040::ADC_GAIN, plasma2040::SHUNT_RESISTOR);
 
 
 int main() {
     stdio_init_all();
 
-    led_strip.start(60);
+    led_strip.start(UPDATES);
 
-    int speed = 10;
+    int speed = DEFAULT_SPEED;
     float offset = 0.0f;
 
+    uint count = 0;
     while (true) {
+        bool sw = user_sw.read();
         bool a = button_a.read();
         bool b = button_b.read();
 
+        if(sw) {
+            speed = DEFAULT_SPEED;
+        }
+        else {
             if(a) speed--;
             if(b) speed++;
+        }
         speed = std::min((int)255, std::max((int)1, speed));
 
         offset += float(speed) / 2000.0f;
@@ -59,8 +78,15 @@ int main() {
 
         led.set_rgb(speed, 0, 255 - speed);
 
+        count += 1;
+        if(count >= UPDATES) {
+            // Display the current value once every second
+            printf("Current = %f A\n", sense.read_current());
+            count = 0;
+        }
+
         // Sleep time controls the rate at which the LED buffer is updated
         // but *not* the actual framerate at which the buffer is sent to the LEDs
-        sleep_ms(1000 / 60);
+        sleep_ms(1000 / UPDATES);
     }
 }

examples/plasma2040/plasma2040_rotary.cmake

@@ -0,0 +1,13 @@
+set(OUTPUT_NAME plasma2040_rotary)
+add_executable(${OUTPUT_NAME} plasma2040_rotary.cpp)
+
+target_link_libraries(${OUTPUT_NAME}
+        pico_stdlib
+        plasma2040
+        breakout_encoder
+        pimoroni_i2c
+        rgbled
+        button
+        )
+
+pico_add_extra_outputs(${OUTPUT_NAME})

examples/plasma2040/plasma2040_rotary.cpp

@@ -12,24 +12,28 @@
 #include "button.hpp"
 
 using namespace pimoroni;
+using namespace plasma;
 
 // Set how many LEDs you have
 const uint N_LEDS = 30;
 
+// How many times the LEDs will be updated per second
+const uint UPDATES = 60;
+
 // Pick *one* LED type by uncommenting the relevant line below:
 
 // APA102-style LEDs with Data/Clock lines. AKA DotStar
-//plasma::APA102 led_strip(N_LEDS, pio0, 0, plasma::PIN_DAT, plasma::PIN_CLK);
+//APA102 led_strip(N_LEDS, pio0, 0, plasma2040::DAT, plasma2040::CLK);
 
 // WS28X-style LEDs with a single signal line. AKA NeoPixel
-plasma::WS2812 led_strip(N_LEDS, pio0, 0, plasma::PIN_DAT);
+WS2812 led_strip(N_LEDS, pio0, 0, plasma2040::DAT);
 
 
 
-Button button_a(plasma::BUTTON_A);
-Button button_b(plasma::BUTTON_B);
+Button button_a(plasma2040::BUTTON_A);
+Button button_b(plasma2040::BUTTON_B);
 
-RGBLED led(plasma::LED_R, plasma::LED_G, plasma::LED_B);
+RGBLED led(plasma2040::LED_R, plasma2040::LED_G, plasma2040::LED_B);
 
 I2C i2c(BOARD::PICO_EXPLORER);
 BreakoutEncoder enc(&i2c);
@@ -67,7 +71,7 @@ void gauge(uint v, uint vmax = 100) {
 int main() {
     stdio_init_all();
 
-    led_strip.start(60);
+    led_strip.start(UPDATES);
 
     bool encoder_detected = enc.init();
     enc.clear_interrupt_flag();
@@ -147,6 +151,6 @@ int main() {
 
         // Sleep time controls the rate at which the LED buffer is updated
         // but *not* the actual framerate at which the buffer is sent to the LEDs
-        sleep_ms(1000 / 60);
+        sleep_ms(1000 / UPDATES);
     }
 }

examples/plasma2040/plasma2040_stacker.cpp

@@ -21,6 +21,7 @@ by Gee 'Rabid Inventor' Bartlett
 */
 
 using namespace pimoroni;
+using namespace plasma;
 
 // Set how many LEDs you have
 const uint N_LEDS = 40;
@@ -29,18 +30,18 @@ const uint REFRESH_DELAY = 100;
 // Pick *one* LED type by uncommenting the relevant line below:
 
 // APA102-style LEDs with Data/Clock lines. AKA DotStar
-//plasma::APA102 led_strip(N_LEDS, pio0, 0, plasma::PIN_DAT, plasma::PIN_CLK);
+//APA102 led_strip(N_LEDS, pio0, 0, plasma2040::DAT, plasma2040::CLK);
 
 // WS28X-style LEDs with a single signal line. AKA NeoPixel
 // by default the WS2812 LED strip will be 400KHz, RGB with no white element
-//plasma::WS2812 led_strip(N_LEDS, pio0, 0, plasma::PIN_DAT);
+//WS2812 led_strip(N_LEDS, pio0, 0, plasma2040::DAT);
 
 //Uncomment for WS2812 with RGBW running at 800KHz
-plasma::WS2812 led_strip(N_LEDS, pio0, 0, plasma::PIN_DAT, 800000, true);
+WS2812 led_strip(N_LEDS, pio0, 0, plasma2040::DAT, 800000, true);
 
-Button button_a(plasma::BUTTON_A, Polarity::ACTIVE_LOW, 50);
-Button button_b(plasma::BUTTON_B, Polarity::ACTIVE_LOW, 50);
-RGBLED led(plasma::LED_R, plasma::LED_G, plasma::LED_B);
+Button button_a(plasma2040::BUTTON_A, Polarity::ACTIVE_LOW, 50);
+Button button_b(plasma2040::BUTTON_B, Polarity::ACTIVE_LOW, 50);
+RGBLED led(plasma2040::LED_R, plasma2040::LED_G, plasma2040::LED_B);
 
 
 class playfield_object{

examples/plasma_2040/plasma2040_rainbow.cmake

@@ -1,10 +0,0 @@
-add_executable(plasma2040_rainbow plasma2040_rainbow.cpp)
-
-target_link_libraries(plasma2040_rainbow
-        pico_stdlib
-        plasma2040
-        rgbled
-        button
-        )
-
-pico_add_extra_outputs(plasma2040_rainbow)

examples/plasma_2040/plasma2040_rotary.cmake

@@ -1,12 +0,0 @@
-add_executable(plasma2040_rotary plasma2040_rotary.cpp)
-
-target_link_libraries(plasma2040_rotary
-        pico_stdlib
-        plasma2040
-        breakout_encoder
-        pimoroni_i2c
-        rgbled
-        button
-        )
-
-pico_add_extra_outputs(plasma2040_rotary)

libraries/plasma2040/plasma2040.cmake

@@ -1,17 +1,6 @@
 add_library(plasma2040 INTERFACE)
 
-target_sources(plasma2040 INTERFACE
-  ${CMAKE_CURRENT_LIST_DIR}/apa102.cpp
-  ${CMAKE_CURRENT_LIST_DIR}/ws2812.cpp
-)
-
 target_include_directories(plasma2040 INTERFACE ${CMAKE_CURRENT_LIST_DIR})
 
-target_link_libraries(plasma2040 INTERFACE
-    pico_stdlib
-    hardware_pio
-    hardware_dma
-    )
-
-pico_generate_pio_header(plasma2040 ${CMAKE_CURRENT_LIST_DIR}/apa102.pio)
-pico_generate_pio_header(plasma2040 ${CMAKE_CURRENT_LIST_DIR}/ws2812.pio)
+# Pull in pico libraries that we need
+target_link_libraries(plasma2040 INTERFACE pico_stdlib plasma)

libraries/plasma2040/plasma2040.hpp

@@ -5,6 +5,7 @@
 #include "ws2812.hpp"
 
 namespace plasma {
+  namespace plasma2040 {
     const uint LED_R = 16;
     const uint LED_G = 17;
     const uint LED_B = 18;
@@ -12,6 +13,14 @@ const uint LED_B = 18;
     const uint BUTTON_A = 12;
     const uint BUTTON_B = 13;
 
-const uint PIN_CLK = 14; // Used only for APA102
-const uint PIN_DAT = 15; // Used for both APA102 and WS2812
+    const uint USER_SW = 23;
+
+    const uint CLK = 14; // Used only for APA102
+    const uint DAT = 15; // Used for both APA102 and WS2812
+
+    const uint CURRENT_SENSE = 29; // The pin used for current sensing
+
+    constexpr float ADC_GAIN = 50;
+    constexpr float SHUNT_RESISTOR = 0.015f;
+  }
 }

micropython/examples/plasma_2040/rainbow.py

@@ -1,19 +1,73 @@
 import plasma
+from plasma import plasma2040
 import time
 
+# Import helpers for RGB LEDs, Buttons, and Analog
+from pimoroni import RGBLED, Button, Analog
+
+# Press "B" to speed up the LED cycling effect.
+# Press "A" to slow it down again.
+# Press "Boot" to reset the speed back to default.
+
+# Set how many LEDs you have
 NUM_LEDS = 30
 
-# WS2812 / NeoPixel™ LEDs
-led_strip = plasma.WS2812(NUM_LEDS, 0, 0, 15)
+# The speed that the LEDs will start cycling at
+DEFAULT_SPEED = 10
+
+# How many times the LEDs will be updated per second
+UPDATES = 60
+
+
+# Pick *one* LED type by uncommenting the relevant line below:
+
 # APA102 / DotStar™ LEDs
-# led_strip = plasma.APA102(NUM_LEDS, 0, 0, 15, 14)
+# led_strip = plasma.APA102(NUM_LEDS, 0, 0, plasma2040.DAT, plasma2040.CLK)
+
+# WS2812 / NeoPixel™ LEDs
+led_strip = plasma.WS2812(NUM_LEDS, 0, 0, plasma2040.DAT)
+
+user_sw = Button(plasma2040.USER_SW)
+button_a = Button(plasma2040.BUTTON_A)
+button_b = Button(plasma2040.BUTTON_B)
+led = RGBLED(plasma2040.LED_R, plasma2040.LED_G, plasma2040.LED_B)
+sense = Analog(plasma2040.CURRENT_SENSE, plasma2040.ADC_GAIN, plasma2040.SHUNT_RESISTOR)
 
 # Start updating the LED strip
 led_strip.start()
 
+speed = DEFAULT_SPEED
+offset = 0.0
+
+count = 0
 # Make rainbows
 while True:
-    t = time.ticks_ms() / 1000.0 / 5.0
+    sw = user_sw.read()
+    a = button_a.read()
+    b = button_b.read()
+
+    if sw:
+        speed = DEFAULT_SPEED
+    else:
+        if a:
+            speed -= 1
+        if b:
+            speed += 1
+
+    speed = min(255, max(1, speed))
+
+    offset += float(speed) / 2000.0
+
     for i in range(NUM_LEDS):
-        led_strip.set_hsv(i, t + (i / NUM_LEDS))
-    time.sleep(1.0 / 60)
+        hue = float(i) / NUM_LEDS
+        led_strip.set_hsv(i, hue + offset, 1.0, 1.0)
+
+    led.set_rgb(speed, 0, 255 - speed)
+
+    count += 1
+    if count >= UPDATES:
+        # Display the current value once every second
+        print("Current =", sense.read_current(), "A")
+        count = 0
+
+    time.sleep(1.0 / UPDATES)

micropython/examples/plasma_2040/rgb-led-and-buttons.py

@@ -1,18 +1,22 @@
 import time
 
-# Import pin constants from plasma
-from plasma import PIN_LED_R, PIN_LED_G, PIN_LED_B, PIN_BUTTON_A, PIN_BUTTON_B
+# Import plasma2040
+from plasma import plasma2040
 
 # Import helpers for RGB LEDs and Buttons
 from pimoroni import RGBLED, Button
 
-led = RGBLED(PIN_LED_R, PIN_LED_G, PIN_LED_B)
-led.set_rgb(255, 0, 0)
+led = RGBLED(plasma2040.LED_R, plasma2040.LED_G, plasma2040.LED_B)
+led.set_rgb(0, 0, 0)
 
-button_a = Button(PIN_BUTTON_A)
-button_b = Button(PIN_BUTTON_B)
+user_sw = Button(plasma2040.USER_SW)
+button_a = Button(plasma2040.BUTTON_A)
+button_b = Button(plasma2040.BUTTON_B)
 
 while True:
+    if user_sw.read():
+        print("Pressed User SW - {}".format(time.ticks_ms()))
+        led.set_rgb(255, 0, 0)
     if button_a.read():
         print("Pressed A - {}".format(time.ticks_ms()))
         led.set_rgb(0, 255, 0)

micropython/modules/micropython.cmake

@@ -32,5 +32,5 @@ include(pico_unicorn/micropython)
 include(pico_display/micropython)
 include(pico_explorer/micropython)
 include(pico_wireless/micropython)
-include(plasma_2040/micropython)
+include(plasma/micropython)
 include(ulab/code/micropython)

micropython/modules/plasma/README.md

@@ -18,6 +18,8 @@ The Plasma library is intended to drive APA102 / DotStar™ or WS2812 / NeoPixel
 - [Using the Buttons & RGB LED](#using-the-buttons--rgb-led)
   - [Buttons](#buttons)
   - [RGBLED](#rgbled)
+- [Measuring LED Strip Current Draw](#measuring-led-strip-current-draw)
+  - [Analog](#analog)
 
 ## Notes On PIO Limitations
 
@@ -33,11 +35,12 @@ Construct a new `WS2812` instance, specifying the number of LEDs, PIO, PIO state
 
 ```python
 import plasma
+from plasma import plasma2040
 
 LEDS = 30
 FPS = 60
 
-led_strip = plasma.WS2812(LEDS, 0, 0, 15)
+led_strip = plasma.WS2812(LEDS, 0, 0, plasma2040.DAT)
 ```
 
 Start the LED strip by calling `start`. This sets up a timer which tells the RP2040 to DMA the pixel data into the PIO (a fast, asyncronous memory->peripheral copy) at the specified framerate.
@@ -50,13 +53,14 @@ led_strip.start(FPS)
 
 Some WS2812-style LED strips have varying colour orders and support an additional white element. Two keyword arguments are supplied to configure this:
 
-```
+```python
 import plasma
+from plasma import plasma2040
 
 LEDS = 30
 FPS = 60
 
-led_strip = plasma.WS2812(LEDS, 0, 0, 15, rgbw=True, color_order=plasma.COLOR_ORDER_GRB)
+led_strip = plasma.WS2812(LEDS, 0, 0, plasma2040.DAT, rgbw=True, color_order=plasma.COLOR_ORDER_GRB)
 ```
 
 The available orders are defined as constants in `plasma`:
@@ -106,11 +110,12 @@ Construct a new `APA102` instance, specifying the number of LEDs, PIO, PIO state
 
 ```python
 import plasma
+from plasma import plasma2040
 
 LEDS = 30
 FPS = 60
 
-led_strip = plasma.APA102(LEDS, 0, 0, 15, 14)
+led_strip = plasma.APA102(LEDS, 0, 0, plasma2040.DAT, plasma2040.CLK)
 ```
 
 Start the LED strip by calling `start`. This sets up a timer which tells the RP2040 to DMA the pixel data into the PIO (a fast, asyncronous memory->peripheral copy) at the specified framerate.
@@ -151,13 +156,14 @@ Button(button, invert=True, repeat_time=200, hold_time=1000)
 RGBLED(r, g, b, invert=True)
 ```
 
-The `plasma` module contains constants for the LED and button pins:
+The `plasma` module contains a `plasma2040` sub module with constants for the LED and button pins:
 
-* `plasma.PIN_LED_R` = 16
-* `plasma.PIN_LED_G` = 17
-* `plasma.PIN_LED_B` = 18
-* `plasma.PIN_BUTTON_A` = 12
-* `plasma.PIN_BUTTON_B` = 13
+* `plasma2040.LED_R` = 16
+* `plasma2040.LED_G` = 17
+* `plasma2040.LED_B` = 18
+* `plasma2040.BUTTON_A` = 12
+* `plasma2040.BUTTON_B` = 13
+* `plasma2040.USER_SW` = 23
 
 ### Buttons
 
@@ -165,14 +171,14 @@ Import the `Button` class from the `pimoroni` module and the pin constants for t
 
 ```python
 from pimoroni import Button
-from plasma import PIN_BUTTON_A, PIN_BUTTON_B
+from plasma import plasma2040
 ```
 
 Set up an instance of `Button` for each button:
 
 ```python
-button_a = Button(PIN_BUTTON_A)
-button_b = Button(PIN_BUTTON_B)
+button_a = Button(plasma2040.BUTTON_A)
+button_b = Button(plasma2040.BUTTON_B)
 ```
 
 To get the button state, call `.read()`. If the button is held down, then this will return `True` at the interval specified by `repeat_time` until `hold_time` is reached, at which point it will return `True` every `hold_time / 3` milliseconds. This is useful for rapidly increasing/decreasing values such as hue:
@@ -183,17 +189,17 @@ state = button_a.read()
 
 ### RGBLED
 
-Import the `RGBLED` class from `pimoroni` and the pin constants for the buttons:
+Import the `RGBLED` class from `pimoroni` and the pin constants for the LED:
 
 ```python
 from pimoroni import RGBLED
-from plasma import PIN_LED_R, PIN_LED_G, PIN_LED_B
+from plasma import plasma2040
 ```
 
 And set up an instance of `RGBLED` for the LED:
 
 ```python
-led = RGBLED(PIN_LED_R, PIN_LED_G, PIN_LED_B)
+led = RGBLED(plasma2040.LED_R, plasma2040.LED_G, plasma2040.LED_B)
 ```
 
 To set the LED colour, call `.set_rgb(r, g, b)`. Each value should be between 0 and 255:
@@ -203,3 +209,40 @@ led.set_rgb(255, 0, 0)  # Full red
 led.set_rgb(0, 255, 0)  # Full green
 led.set_rgb(0, 0, 255)  # Full blue
 ```
+
+## Measuring LED Strip Current Draw
+
+Plasma 2040 feasures low-side current sensing, letting you measure how much current a strip of LEDs is drawing. This could be used just for monitoring, or as a way to reduce the maximum brightness of a strip to keep its current draw within the range of the USB port or power supply being used.
+
+The `pimoroni` module contains an `Analog` class to simplify the reading of this current draw.
+
+```python
+Analog(pin, amplifier_gain=1, resistor=0)
+```
+
+The `plasma` module contains a `plasma2040` sub module with constants for the current sensing:
+
+* `plasma2040.CURRENT_SENSE` = 29
+* `plasma2040.ADC_GAIN` = 50
+* `plasma2040.SHUNT_RESISTOR` = 0.015
+
+### Analog
+
+Import the `Analog` class from `pimoroni` and the pin and gain constants for the current sensing:
+
+```python
+from pimoroni import Analog
+from plasma import plasma2040
+```
+
+And set up an instance of `Analog` for the current sensing:
+
+```python
+sense = Analog(plasma2040.CURRENT_SENSE, plasma2040.ADC_GAIN, plasma2040.SHUNT_RESISTOR)
+```
+
+To read the current draw, call `.read_current()`. The returned value will be in amps (A):
+
+```python
+print("Current =", sense.read_current(), "A")
+```

micropython/modules/plasma/micropython.cmake

@@ -1,19 +1,19 @@
-set(MOD_NAME plasma_2040)
+set(MOD_NAME plasma)
 string(TOUPPER ${MOD_NAME} MOD_NAME_UPPER)
 add_library(usermod_${MOD_NAME} INTERFACE)
 
 target_sources(usermod_${MOD_NAME} INTERFACE
     ${CMAKE_CURRENT_LIST_DIR}/${MOD_NAME}.c
     ${CMAKE_CURRENT_LIST_DIR}/${MOD_NAME}.cpp
-    ${CMAKE_CURRENT_LIST_DIR}/../../../libraries/plasma2040/apa102.cpp
-    ${CMAKE_CURRENT_LIST_DIR}/../../../libraries/plasma2040/ws2812.cpp
+    ${CMAKE_CURRENT_LIST_DIR}/../../../drivers/plasma/apa102.cpp
+    ${CMAKE_CURRENT_LIST_DIR}/../../../drivers/plasma/ws2812.cpp
 )
-pico_generate_pio_header(usermod_${MOD_NAME} ${CMAKE_CURRENT_LIST_DIR}/../../../libraries/plasma2040/apa102.pio)
-pico_generate_pio_header(usermod_${MOD_NAME} ${CMAKE_CURRENT_LIST_DIR}/../../../libraries/plasma2040/ws2812.pio)
+pico_generate_pio_header(usermod_${MOD_NAME} ${CMAKE_CURRENT_LIST_DIR}/../../../drivers/plasma/apa102.pio)
+pico_generate_pio_header(usermod_${MOD_NAME} ${CMAKE_CURRENT_LIST_DIR}/../../../drivers/plasma/ws2812.pio)
 
 target_include_directories(usermod_${MOD_NAME} INTERFACE
     ${CMAKE_CURRENT_LIST_DIR}
-    ${CMAKE_CURRENT_LIST_DIR}/../../../libraries/plasma2040/
+    ${CMAKE_CURRENT_LIST_DIR}/../../../drivers/plasma/
 )
 
 target_compile_definitions(usermod_${MOD_NAME} INTERFACE

micropython/modules/plasma/plasma.c

@@ -1,4 +1,4 @@
-#include "plasma_2040.h"
+#include "plasma.h"
 
 
 /***** Methods *****/
@@ -59,15 +59,33 @@ typedef struct _mp_obj_float_t {
 mp_obj_float_t shunt_resistor = {{&mp_type_float}, 0.015f};
 
 /***** Globals Table *****/
+STATIC const mp_map_elem_t plasma2040_globals_table[] = {
+    { MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_plasma2040) },
+    { MP_ROM_QSTR(MP_QSTR_LED_R), MP_ROM_INT(16) },
+    { MP_ROM_QSTR(MP_QSTR_LED_G), MP_ROM_INT(17) },
+    { MP_ROM_QSTR(MP_QSTR_LED_B), MP_ROM_INT(18) },
+    { MP_ROM_QSTR(MP_QSTR_BUTTON_A), MP_ROM_INT(12) },
+    { MP_ROM_QSTR(MP_QSTR_BUTTON_B), MP_ROM_INT(13) },
+    { MP_ROM_QSTR(MP_QSTR_USER_SW), MP_ROM_INT(23) },
+    { MP_ROM_QSTR(MP_QSTR_CLK), MP_ROM_INT(14) },
+    { MP_ROM_QSTR(MP_QSTR_DAT), MP_ROM_INT(15) },
+    { MP_ROM_QSTR(MP_QSTR_CURRENT_SENSE), MP_ROM_INT(29) },
+
+    { MP_ROM_QSTR(MP_QSTR_SHUNT_RESISTOR), MP_ROM_PTR(&shunt_resistor) },
+    { MP_ROM_QSTR(MP_QSTR_ADC_GAIN), MP_ROM_INT(50) },
+};
+STATIC MP_DEFINE_CONST_DICT(mp_module_plasma2040_globals, plasma2040_globals_table);
+
+const mp_obj_module_t plasma2040_user_cmodule = {
+    .base = { &mp_type_module },
+    .globals = (mp_obj_dict_t*)&mp_module_plasma2040_globals,
+};
+
 STATIC const mp_map_elem_t plasma_globals_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_plasma) },
     { MP_OBJ_NEW_QSTR(MP_QSTR_APA102), (mp_obj_t)&PlasmaAPA102_type },
     { MP_OBJ_NEW_QSTR(MP_QSTR_WS2812), (mp_obj_t)&PlasmaWS2812_type },
-    { MP_ROM_QSTR(MP_QSTR_PIN_LED_R), MP_ROM_INT(16) },
-    { MP_ROM_QSTR(MP_QSTR_PIN_LED_G), MP_ROM_INT(17) },
-    { MP_ROM_QSTR(MP_QSTR_PIN_LED_B), MP_ROM_INT(18) },
-    { MP_ROM_QSTR(MP_QSTR_PIN_BUTTON_A), MP_ROM_INT(12) },
-    { MP_ROM_QSTR(MP_QSTR_PIN_BUTTON_B), MP_ROM_INT(13) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_plasma2040), (mp_obj_t)&plasma2040_user_cmodule },
 
     { MP_ROM_QSTR(MP_QSTR_COLOR_ORDER_RGB), MP_ROM_INT(0x00) },
     { MP_ROM_QSTR(MP_QSTR_COLOR_ORDER_RBG), MP_ROM_INT(0x01) },
@@ -75,9 +93,6 @@ STATIC const mp_map_elem_t plasma_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_COLOR_ORDER_GBR), MP_ROM_INT(0x03) },
     { MP_ROM_QSTR(MP_QSTR_COLOR_ORDER_BRG), MP_ROM_INT(0x04) },
     { MP_ROM_QSTR(MP_QSTR_COLOR_ORDER_BGR), MP_ROM_INT(0x05) },
-
-    { MP_ROM_QSTR(MP_QSTR_SHUNT_RESISTOR), MP_ROM_PTR(&shunt_resistor) },
-    { MP_ROM_QSTR(MP_QSTR_ADC_GAIN), MP_ROM_INT(50) },
 };
 STATIC MP_DEFINE_CONST_DICT(mp_module_plasma_globals, plasma_globals_table);
 

micropython/modules/plasma/plasma.cpp

@@ -1,4 +1,5 @@
-#include "libraries/plasma2040/plasma2040.hpp"
+#include "drivers/plasma/ws2812.hpp"
+#include "drivers/plasma/apa102.hpp"
 #include <cstdio>
 
 #define MP_OBJ_TO_PTR2(o, t) ((t *)(uintptr_t)(o))
@@ -11,7 +12,7 @@
 using namespace plasma;
 
 extern "C" {
-#include "plasma_2040.h"
+#include "plasma.h"
 #include "py/builtin.h"
 
 typedef struct _mp_obj_float_t {

micropython/modules_py/pimoroni.py

@@ -80,6 +80,6 @@ class RGBLED:
             r = 255 - r
             g = 255 - g
             b = 255 - b
-        self.led_r.duty_u16(r * 255)
-        self.led_g.duty_u16(g * 255)
-        self.led_b.duty_u16(b * 255)
+        self.led_r.duty_u16(int((r * 65535) / 255))
+        self.led_g.duty_u16(int((g * 65535) / 255))
+        self.led_b.duty_u16(int((b * 65535) / 255))