From e1c963e10bc0c41eb4235ec1398c790a46a31963 Mon Sep 17 00:00:00 2001
From: Thomas Kolb <thomas@tkolb.de>
Date: Tue, 20 Dec 2022 21:21:20 +0100
Subject: [PATCH] First PWM test

---
 CMakeLists.txt |  4 +++-
 src/main.c     | 54 ++++++++++++++++++++++++++++++++------------------
 2 files changed, 38 insertions(+), 20 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 94d5563..dfdeee2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -17,4 +17,6 @@ pico_enable_stdio_usb(${CMAKE_PROJECT_NAME} 1)
 pico_enable_stdio_uart(${CMAKE_PROJECT_NAME} 0)
 pico_add_extra_outputs(${CMAKE_PROJECT_NAME})
 
-target_link_libraries(${CMAKE_PROJECT_NAME} pico_stdlib)
+target_link_libraries(${CMAKE_PROJECT_NAME}
+	pico_stdlib
+	hardware_pwm)
diff --git a/src/main.c b/src/main.c
index 59e7788..c8d3d0c 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,40 +1,56 @@
 #include "hardware/gpio.h"
+#include "hardware/pwm.h"
 //#include <stdio.h>
 #include <pico/stdlib.h>
 
-#define LED1_PIN 13
-#define LED2_PIN 14
-#define LED3_PIN 15
+#define LEDY_PIN 13
+#define LEDG_PIN 14
+#define LEDR_PIN 15
+
+#define POWER_SWITCH_PIN 10
 
 int main()
 {
 	//stdio_init_all();
 	//printf("Hello, world!\n");
 
-	gpio_init(LED1_PIN);
-	gpio_init(LED2_PIN);
-	gpio_init(LED3_PIN);
+	bool power_switch_state = false;
 
-	gpio_set_dir(LED1_PIN, true);
-	gpio_set_dir(LED2_PIN, true);
-	gpio_set_dir(LED3_PIN, true);
+	gpio_init(LEDY_PIN);
+	gpio_init(LEDG_PIN);
+	gpio_init(LEDR_PIN);
 
-	gpio_put(LED1_PIN, true);
-	gpio_put(LED2_PIN, true);
-	gpio_put(LED3_PIN, true);
+	gpio_set_dir(LEDY_PIN, true);
+	gpio_set_dir(LEDG_PIN, true);
+	gpio_set_dir(LEDR_PIN, true);
+
+	gpio_put(LEDY_PIN, true);
+	gpio_put(LEDG_PIN, true);
+	gpio_put(LEDR_PIN, true);
+
+	// set up PWM for 50 kHz @ 512 steps resolution
+	uint slice_num = pwm_gpio_to_slice_num(POWER_SWITCH_PIN);
+
+	pwm_set_clkdiv_int_frac(slice_num, 4, (88 << 4) / 100);
+	gpio_set_function(POWER_SWITCH_PIN, GPIO_FUNC_PWM);
+	pwm_set_wrap(slice_num, 512);
+	pwm_set_chan_level(slice_num, PWM_CHAN_A, 410);
+	pwm_set_enabled(slice_num, true);
 
 	sleep_ms(3000);
 
+	gpio_put(LEDY_PIN, false);
+	gpio_put(LEDG_PIN, false);
+
 	while (true) {
-		gpio_put(LED1_PIN, true);
-		gpio_put(LED2_PIN, false);
-		gpio_put(LED3_PIN, false);
+		gpio_put(LEDR_PIN, true);
+		gpio_put(LEDG_PIN, false);
 		sleep_ms(500);
-		gpio_put(LED1_PIN, false);
-		gpio_put(LED2_PIN, true);
+		gpio_put(LEDY_PIN, true);
+		gpio_put(LEDR_PIN, false);
 		sleep_ms(500);
-		gpio_put(LED2_PIN, false);
-		gpio_put(LED3_PIN, true);
+		gpio_put(LEDY_PIN, false);
+		gpio_put(LEDG_PIN, true);
 		sleep_ms(500);
 	}
 	return 0;