diff --git a/pid.h b/pid.h
--- a/pid.h
+++ b/pid.h
@@ -1,8 +1,16 @@
 #ifndef PIDS_H
 #define PIDS_H
 
+#include "stm32f0xx_hal.h"
 #include "states.h"
 
-int16_t pid_update(uint16_t k_p, uint16_t k_i, uint16_t k_d, int16_t temp, uint8_t temp_frac, int16_t setpoint, therm_settings_t* set, therm_status_t* status);
+typedef struct {
+	int16_t last_pid_temp;
+	uint8_t last_pid_temp_frac;
+	int32_t i_state;
+} pid_state_t;
+
+void pid_init(pid_state_t* state);
+int16_t pid_update(therm_settings_t* set, therm_status_t* status, pid_state_t* state);
 
 #endif