--- /dev/null
+/*
+ * Copyright © 2016 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#ifndef _AO_SERVO_H_
+#define _AO_SERVO_H_
+
+void
+ao_servo_run(uint16_t speed, uint8_t dir, uint16_t timeout);
+
+void
+ao_servo_init(void);
+
+#define AO_SERVO_FORE 0
+#define AO_SERVO_BACK 1
+
+/* To configure the servo:
+ *
+ * #define AO_SERVO_PWM <pwm index>
+ * #define AO_SERVO_DIR_PORT <gpio>
+ * #define AO_SERVO_DIR_PIN <pin>
+ * #define AO_SERVO_LIMIT_FORE_PORT <gpio>
+ * #define AO_SERVO_LIMIT_FORE_PIN <pin>
+ * #define AO_SERVO_LIMIT_BACK_PORT <gpio>
+ * #define AO_SERVO_LIMIT_BACK_PIN <pin>
+ */
+
+#endif /* _AO_SERVO_H_ */