diff --git a/src/pwmout.c b/src/pwmout.c
--- a/src/pwmout.c
+++ b/src/pwmout.c
@@ -8,11 +8,13 @@
 #include "flash.h"
 #include "error.h"
 
-TIM_HandleTypeDef htim17;
 
+// Private variables
+static TIM_HandleTypeDef htim17;
 static uint32_t last_ssr_on = 0;
 
 
+// Initialize hardware PWM output
 void pwmout_init(void)
 {
 	GPIO_InitTypeDef GPIO_InitStruct;
@@ -100,6 +102,8 @@ void pwmout_process(int16_t duty)
 	htim17.Instance->CCR1 = duty; //duty;
 }
 
+
+// Accessor for timer handle
 TIM_HandleTypeDef* pwmout_get_tim(void)
 {
 	return &htim17;