add pwm

firmware/Makefile

@@ -119,6 +119,7 @@ CSRC = $(ALLCSRC) cfg/board.c
 # C++ sources that can be compiled in ARM or THUMB mode depending on the global
 # setting.
 CPPSRC = $(ALLCPPSRC) \
+          pwm.cpp \
           main.cpp
 
 # List ASM source files here.

firmware/main.cpp

@@ -1,6 +1,14 @@
 #include "ch.h"
 #include "hal.h"
 
+#include "pwm.h"
+
+// 400khz / 1024 = 390hz PWM
+Pwm heaterPwm(PWMD1, 1, 400000, 1024);
+
+// 48MHz / 1024 = 46.8khz PWM
+Pwm pumpDac(PWMD3, 1, 48000000, 1024);
+
 /*
  * Application entry point.
  */
@@ -8,6 +16,9 @@ int main(void) {
   halInit();
   chSysInit();
 
+  heaterPwm.Start();
+  pumpDac.Start();
+
   while (true) {
 
   }

firmware/pwm.cpp

@@ -0,0 +1,37 @@
+#include "pwm.h"
+
+#include "ch.h"
+#include "hal.h"
+
+Pwm::Pwm(PWMDriver& driver, uint8_t channel, uint32_t counterFrequency, uint32_t counterPeriod)
+    : m_driver(&driver)
+    , m_channel(channel)
+    , m_counterFrequency(m_counterFrequency)
+    , m_counterPeriod(counterPeriod)
+{
+}
+
+void Pwm::Start()
+{
+    PWMConfig config = {
+        m_counterFrequency,
+        m_counterPeriod,
+        nullptr,
+        {
+            {PWM_OUTPUT_ACTIVE_HIGH, nullptr},
+            {PWM_OUTPUT_ACTIVE_HIGH, nullptr},
+            {PWM_OUTPUT_ACTIVE_HIGH, nullptr},
+            {PWM_OUTPUT_ACTIVE_HIGH, nullptr}
+        },
+        0,
+        0
+    };
+
+    pwmStart(m_driver, &config);
+}
+
+void Pwm::SetDuty(float duty) {
+    pwmcnt_t highTime = m_counterPeriod * duty;
+
+    pwm_lld_enable_channel(m_driver, m_channel, highTime);
+}

firmware/pwm.h

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <cstdint>
+
+struct PWMDriver;
+
+class Pwm
+{
+public:
+    Pwm(PWMDriver& driver, uint8_t channel, uint32_t counterFrequency, uint32_t counterPeriod);
+
+    void Start();
+    void SetDuty(float duty);
+private:
+    PWMDriver* const m_driver;
+    const uint8_t m_channel;
+    const uint32_t m_counterFrequency;
+    const uint16_t m_counterPeriod;
+};