diff --git a/src/pwmout.c b/src/pwmout.c
new file mode 100644
--- /dev/null
+++ b/src/pwmout.c
@@ -0,0 +1,63 @@
+//
+// PWM Out: generate PWM waveform to control factory
+//
+
+#include "pwmout.h"
+#include "gpio.h"
+#include "flash.h"
+
+
+static uint32_t last_ssr_on = 0;
+
+
+void pwmout_init(void)
+{
+	GPIO_InitTypeDef GPIO_InitStruct;
+
+	// Configure LED GPIO pins
+	GPIO_InitStruct.Pin = SSR_PIN;
+	GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
+	GPIO_InitStruct.Pull = GPIO_NOPULL;
+	GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
+	HAL_GPIO_Init(SSR_GPIO_Port, &GPIO_InitStruct);
+
+}
+
+
+// freaking integral term isn't compatible with both heating and cooling... due to the discard
+// functionality. this is a problem.
+
+// also duty cycling isn't working correctly...
+void pwmout_process(float duty)
+{
+
+	uint32_t ssr_output = duty; // meh
+
+	// Kill SSR once the desired on-time has elapsed
+	if(flash_getsettings()->val.control_mode == MODE_PID && ((HAL_GetTick() - last_ssr_on > ssr_output) || ssr_output <= 0))
+	{
+		HAL_GPIO_WritePin(SSR, 0);
+		HAL_GPIO_WritePin(LED, 0);
+	}
+
+
+	// Every 200ms, set the SSR on unless output is 0
+	if(flash_getsettings()->val.control_mode == MODE_PID && HAL_GetTick() - last_ssr_on > SSR_PERIOD)
+	{
+		// Heat or cool, if we need to
+		if(ssr_output > 0)
+		{
+			HAL_GPIO_WritePin(SSR, 1);
+			HAL_GPIO_WritePin(LED, 1);
+			last_ssr_on = HAL_GetTick();
+		}
+		else {
+			// Make sure everything is off
+			HAL_GPIO_WritePin(SSR, 0);
+			HAL_GPIO_WritePin(LED, 0);
+		}
+
+	}
+}
+
+