Added C++ examples for IOExpander

examples/CMakeLists.txt

@@ -1,5 +1,6 @@
 add_subdirectory(breakout_dotmatrix)
 add_subdirectory(breakout_encoder)
+add_subdirectory(breakout_ioexpander)
 add_subdirectory(breakout_ltr559)
 add_subdirectory(breakout_colourlcd160x80)
 add_subdirectory(breakout_roundlcd)

examples/breakout_ioexpander/CMakeLists.txt

@@ -1,12 +1,3 @@
-set(OUTPUT_NAME ioexpander_demo)
-
-add_executable(
-  ${OUTPUT_NAME}
-  demo.cpp
-)
-
-# Pull in pico libraries that we need
-target_link_libraries(${OUTPUT_NAME} pico_stdlib breakout_ioexpander)
-
-# create map/bin/hex file etc.
-pico_add_extra_outputs(${OUTPUT_NAME})
+add_subdirectory(adc)
+add_subdirectory(button)
+add_subdirectory(servo)

examples/breakout_ioexpander/adc/CMakeLists.txt

@@ -0,0 +1,16 @@
+set(OUTPUT_NAME ioexpander_adc)
+
+add_executable(
+  ${OUTPUT_NAME}
+  adc.cpp
+)
+
+# enable usb output, disable uart output
+pico_enable_stdio_usb(${OUTPUT_NAME} 1)
+pico_enable_stdio_uart(${OUTPUT_NAME} 0)
+
+# Pull in pico libraries that we need
+target_link_libraries(${OUTPUT_NAME} pico_stdlib breakout_ioexpander)
+
+# create map/bin/hex file etc.
+pico_add_extra_outputs(${OUTPUT_NAME})

examples/breakout_ioexpander/adc/adc.cpp

@@ -0,0 +1,42 @@
+#include "pico/stdlib.h"
+#include <stdio.h>
+
+#include "breakout_ioexpander.hpp"
+
+using namespace pimoroni;
+
+static const uint8_t IOE_ADC_PIN = 10;
+
+BreakoutIOExpander ioe(0x18);
+bool toggle = false;
+
+int main() {
+  gpio_init(PICO_DEFAULT_LED_PIN);
+  gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);
+
+  stdio_init_all();
+
+  if(ioe.init()) {
+    printf("IOExpander found...\n");
+
+    // ioe.set_adc_vref(5.0f);    //Uncomment this if running the IOExpander off a 5V supply
+    ioe.set_mode(IOE_ADC_PIN, IOExpander::PIN_ADC);
+
+    while(true) {
+      gpio_put(PICO_DEFAULT_LED_PIN, toggle);
+      toggle = !toggle;
+
+      float voltage = ioe.input_as_voltage(IOE_ADC_PIN);
+
+      printf("Voltage: %f\n", voltage);
+
+      sleep_ms(20);
+    }
+  }
+  else {
+    printf("IOExpander not found :'(\n");
+    gpio_put(PICO_DEFAULT_LED_PIN, true);
+  }
+
+  return 0;
+}

examples/breakout_ioexpander/button/CMakeLists.txt

@@ -0,0 +1,16 @@
+set(OUTPUT_NAME ioexpander_button)
+
+add_executable(
+  ${OUTPUT_NAME}
+  button.cpp
+)
+
+# enable usb output, disable uart output
+pico_enable_stdio_usb(${OUTPUT_NAME} 1)
+pico_enable_stdio_uart(${OUTPUT_NAME} 0)
+
+# Pull in pico libraries that we need
+target_link_libraries(${OUTPUT_NAME} pico_stdlib breakout_ioexpander)
+
+# create map/bin/hex file etc.
+pico_add_extra_outputs(${OUTPUT_NAME})

examples/breakout_ioexpander/button/button.cpp

@@ -0,0 +1,49 @@
+#include "pico/stdlib.h"
+#include <stdio.h>
+
+#include "breakout_ioexpander.hpp"
+
+using namespace pimoroni;
+
+//Connect a button between this pin and ground
+static const uint8_t IOE_BUTTON_PIN = 14;
+
+BreakoutIOExpander ioe(0x18);
+bool last_state = true;
+
+int main() {
+  gpio_init(PICO_DEFAULT_LED_PIN);
+  gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);
+
+  stdio_init_all();
+
+  if(ioe.init()) {
+    printf("IOExpander found...\n");
+
+    ioe.set_mode(IOE_BUTTON_PIN, IOExpander::PIN_IN_PULL_UP);
+
+    while(true) {
+      bool state = ioe.input(IOE_BUTTON_PIN);
+      if(state != last_state) {
+        if(state) {
+          printf("Button has been released\n");
+          gpio_put(PICO_DEFAULT_LED_PIN, false);
+        }
+        else {
+          printf("Button has been pressed\n");
+          gpio_put(PICO_DEFAULT_LED_PIN, true);
+        }
+
+        last_state = state;
+      }
+
+      sleep_ms(20);
+    }
+  }
+  else {
+    printf("IOExpander not found :'(\n");
+    gpio_put(PICO_DEFAULT_LED_PIN, true);
+  }
+
+  return 0;
+}

examples/breakout_ioexpander/demo.cpp

@@ -1,23 +0,0 @@
-#include "pico/stdlib.h"
-
-#include "breakout_ioexpander.hpp"
-
-using namespace pimoroni;
-
-BreakoutIOExpander ioe;
-
-int main() {
-  gpio_init(PICO_DEFAULT_LED_PIN);
-  gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);
-
-  ioe.init();   
-
-  while(true) {
-    gpio_put(PICO_DEFAULT_LED_PIN, true);
-    sleep_ms(1000);
-    gpio_put(PICO_DEFAULT_LED_PIN, false);
-    sleep_ms(1000);
-  }
-
-  return 0;
-}

examples/breakout_ioexpander/servo/CMakeLists.txt

@@ -0,0 +1,16 @@
+set(OUTPUT_NAME ioexpander_servo)
+
+add_executable(
+  ${OUTPUT_NAME}
+  servo.cpp
+)
+
+# enable usb output, disable uart output
+pico_enable_stdio_usb(${OUTPUT_NAME} 1)
+pico_enable_stdio_uart(${OUTPUT_NAME} 0)
+
+# Pull in pico libraries that we need
+target_link_libraries(${OUTPUT_NAME} pico_stdlib breakout_ioexpander)
+
+# create map/bin/hex file etc.
+pico_add_extra_outputs(${OUTPUT_NAME})

examples/breakout_ioexpander/servo/servo.cpp

@@ -0,0 +1,60 @@
+#include "pico/stdlib.h"
+#include <stdio.h>
+#include <math.h>
+
+#include "breakout_ioexpander.hpp"
+
+using namespace pimoroni;
+
+static const uint8_t IOE_SERVO_PIN = 1;
+
+// Settings to produce a 50Hz output from the 24MHz clock.
+// 24,000,000 Hz / 8 = 3,000,000 Hz
+// 3,000,000 Hz / 60,000 Period = 50 Hz
+static const uint8_t DIVIDER = 8;
+static const uint16_t PERIOD = 60000;
+static constexpr float CYCLE_TIME = 5.0f;
+static constexpr float SERVO_RANGE = 1000.0f;   // Between 1000 and 2000us (1-2ms)
+
+BreakoutIOExpander ioe(0x18);
+bool toggle = false;
+
+int main() {
+  gpio_init(PICO_DEFAULT_LED_PIN);
+  gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);
+
+  stdio_init_all();
+
+  if(ioe.init()) {
+    printf("IOExpander found...\n");
+
+    ioe.set_pwm_period(PERIOD);
+    ioe.set_pwm_control(DIVIDER);
+
+    ioe.set_mode(IOE_SERVO_PIN, IOExpander::PIN_PWM);
+
+    while(true) {
+      gpio_put(PICO_DEFAULT_LED_PIN, toggle);
+      toggle = !toggle;
+
+      absolute_time_t at = get_absolute_time();
+      float t = to_us_since_boot(at) / 1000000.0f;
+      float s = sinf((t * M_PI * 2.0f) / CYCLE_TIME) / 2.0f;
+      float servo_us = 1500.0f + (s * SERVO_RANGE);
+
+      float duty_per_microsecond = (float)PERIOD / (float)(20 * 1000);    // Default is 3 LSB per microsecond
+
+      uint16_t duty_cycle = (uint16_t)(roundf(servo_us * duty_per_microsecond));
+      printf("Cycle Time: %.2f, Pulse: %.1fus, Duty Cycle: %d\n", fmodf(t, CYCLE_TIME), servo_us, duty_cycle);
+      ioe.output(IOE_SERVO_PIN, duty_cycle);
+
+      sleep_ms(20);
+    }
+  }
+  else {
+    printf("IOExpander not found :'(\n");
+    gpio_put(PICO_DEFAULT_LED_PIN, true);
+  }
+
+  return 0;
+}