diff --git a/src/modules/px4iofirmware/CMakeLists.txt b/src/modules/px4iofirmware/CMakeLists.txt
index b29d5b1f86..fe88e8fe66 100644
--- a/src/modules/px4iofirmware/CMakeLists.txt
+++ b/src/modules/px4iofirmware/CMakeLists.txt
@@ -99,11 +99,7 @@ set(srcs
 	safety.c
 	)
 
-if(${config_io_board} STREQUAL "px4io-v1")
-	list(APPEND srcs
-		i2c.c
-		)
-elseif(${config_io_board} STREQUAL "px4io-v2")
+if(${config_io_board} STREQUAL "px4io-v2")
 	list(APPEND srcs
 		serial.c
 		${PX4_SOURCE_DIR}/src/modules/systemlib/hx_stream.c
diff --git a/src/modules/px4iofirmware/protocol.h b/src/modules/px4iofirmware/protocol.h
index f1d0bccbba..76faac1271 100644
--- a/src/modules/px4iofirmware/protocol.h
+++ b/src/modules/px4iofirmware/protocol.h
@@ -193,16 +193,7 @@
 #define PX4IO_P_SETUP_PWM_RATES			2	/* bitmask, 0 = low rate, 1 = high rate */
 #define PX4IO_P_SETUP_PWM_DEFAULTRATE		3	/* 'low' PWM frame output rate in Hz */
 #define PX4IO_P_SETUP_PWM_ALTRATE		4	/* 'high' PWM frame output rate in Hz */
-
-#if defined(CONFIG_ARCH_BOARD_PX4IO_V1) || defined(CONFIG_ARCH_BOARD_PX4FMU_V1)
-#define PX4IO_P_SETUP_RELAYS			5	/* bitmask of relay/switch outputs, 0 = off, 1 = on */
-#define PX4IO_P_SETUP_RELAYS_POWER1		(1<<0)	/* hardware rev [1] power relay 1 */
-#define PX4IO_P_SETUP_RELAYS_POWER2		(1<<1)	/* hardware rev [1] power relay 2 */
-#define PX4IO_P_SETUP_RELAYS_ACC1		(1<<2)	/* hardware rev [1] accessory power 1 */
-#define PX4IO_P_SETUP_RELAYS_ACC2		(1<<3)	/* hardware rev [1] accessory power 2 */
-#else
 #define PX4IO_P_SETUP_RELAYS_PAD		5
-#endif
 
 #define PX4IO_P_SETUP_VBATT_SCALE		6	/* hardware rev [1] battery voltage correction factor (float) */
 #define PX4IO_P_SETUP_VSERVO_SCALE		6	/* hardware rev [2] servo voltage correction factor (float) */
diff --git a/src/modules/px4iofirmware/px4io.h b/src/modules/px4iofirmware/px4io.h
index 795da1af7c..d9f0c14b0e 100644
--- a/src/modules/px4iofirmware/px4io.h
+++ b/src/modules/px4iofirmware/px4io.h
@@ -115,9 +115,6 @@ extern uint16_t			r_page_servo_disarmed[];	/* PX4IO_PAGE_DISARMED_PWM */
 #define r_setup_pwm_rates	r_page_setup[PX4IO_P_SETUP_PWM_RATES]
 #define r_setup_pwm_defaultrate	r_page_setup[PX4IO_P_SETUP_PWM_DEFAULTRATE]
 #define r_setup_pwm_altrate	r_page_setup[PX4IO_P_SETUP_PWM_ALTRATE]
-#ifdef CONFIG_ARCH_BOARD_PX4IO_V1
-#define r_setup_relays		r_page_setup[PX4IO_P_SETUP_RELAYS]
-#endif
 #define r_setup_rc_thr_failsafe	r_page_setup[PX4IO_P_SETUP_RC_THR_FAILSAFE_US]
 
 #define r_setup_pwm_reverse	r_page_setup[PX4IO_P_SETUP_PWM_REVERSE]
@@ -166,25 +163,6 @@ extern pwm_limit_t pwm_limit;
 #define LED_SAFETY(_s)			px4_arch_gpiowrite(GPIO_LED3, !(_s))
 #define LED_RING(_s)			px4_arch_gpiowrite(GPIO_LED4, (_s))
 
-#ifdef CONFIG_ARCH_BOARD_PX4IO_V1
-
-# define PX4IO_RELAY_CHANNELS		4
-# define POWER_SERVO(_s)		px4_arch_gpiowrite(GPIO_SERVO_PWR_EN, (_s))
-# define POWER_ACC1(_s)			px4_arch_gpiowrite(GPIO_ACC1_PWR_EN, (_s))
-# define POWER_ACC2(_s)			px4_arch_gpiowrite(GPIO_ACC2_PWR_EN, (_s))
-# define POWER_RELAY1(_s)		px4_arch_gpiowrite(GPIO_RELAY1_EN, (_s))
-# define POWER_RELAY2(_s)		px4_arch_gpiowrite(GPIO_RELAY2_EN, (_s))
-
-# define OVERCURRENT_ACC		(!px4_arch_gpioread(GPIO_ACC_OC_DETECT))
-# define OVERCURRENT_SERVO		(!px4_arch_gpioread(GPIO_SERVO_OC_DETECT))
-
-# define PX4IO_ADC_CHANNEL_COUNT	2
-# define ADC_VBATT			4
-# define ADC_IN5			5
-
-#endif
-
-#ifdef CONFIG_ARCH_BOARD_PX4IO_V2
 
 # define PX4IO_RELAY_CHANNELS		0
 # define ENABLE_SBUS_OUT(_s)		px4_arch_gpiowrite(GPIO_SBUS_OENABLE, !(_s))
@@ -195,8 +173,6 @@ extern pwm_limit_t pwm_limit;
 # define ADC_VSERVO			4
 # define ADC_RSSI			5
 
-#endif
-
 #define BUTTON_SAFETY		px4_arch_gpioread(GPIO_BTN_SAFETY)
 
 #define CONTROL_PAGE_INDEX(_group, _channel) (_group * PX4IO_CONTROL_CHANNELS + _channel)
diff --git a/src/modules/px4iofirmware/registers.c b/src/modules/px4iofirmware/registers.c
index c5ffc6eee1..afc47f3973 100644
--- a/src/modules/px4iofirmware/registers.c
+++ b/src/modules/px4iofirmware/registers.c
@@ -64,11 +64,7 @@ bool update_mc_thrust_param;
  */
 static const uint16_t	r_page_config[] = {
 	[PX4IO_P_CONFIG_PROTOCOL_VERSION]	= PX4IO_PROTOCOL_VERSION,
-#ifdef CONFIG_ARCH_BOARD_PX4IO_V2
 	[PX4IO_P_CONFIG_HARDWARE_VERSION]	= 2,
-#else
-	[PX4IO_P_CONFIG_HARDWARE_VERSION]	= 1,
-#endif
 	[PX4IO_P_CONFIG_BOOTLOADER_VERSION]	= PX4IO_BL_VERSION,
 	[PX4IO_P_CONFIG_MAX_TRANSFER]		= PX4IO_MAX_TRANSFER_LEN,
 	[PX4IO_P_CONFIG_CONTROL_COUNT]		= PX4IO_CONTROL_CHANNELS,
@@ -156,23 +152,15 @@ uint16_t		r_page_direct_pwm[PX4IO_SERVO_COUNT];
  * Setup registers
  */
 volatile uint16_t	r_page_setup[] = {
-#ifdef CONFIG_ARCH_BOARD_PX4IO_V2
 	/* default to RSSI ADC functionality */
 	[PX4IO_P_SETUP_FEATURES]		= PX4IO_P_SETUP_FEATURES_ADC_RSSI,
-#else
-	[PX4IO_P_SETUP_FEATURES]		= 0,
-#endif
 	[PX4IO_P_SETUP_ARMING]			= (PX4IO_P_SETUP_ARMING_OVERRIDE_IMMEDIATE),
 	[PX4IO_P_SETUP_PWM_RATES]		= 0,
 	[PX4IO_P_SETUP_PWM_DEFAULTRATE]		= 50,
 	[PX4IO_P_SETUP_PWM_ALTRATE]		= 200,
 	[PX4IO_P_SETUP_SBUS_RATE]		= 72,
-#ifdef CONFIG_ARCH_BOARD_PX4IO_V1
-	[PX4IO_P_SETUP_RELAYS]			= 0,
-#else
 	/* this is unused, but we will pad it for readability (the compiler pads it automatically) */
 	[PX4IO_P_SETUP_RELAYS_PAD]		= 0,
-#endif
 #ifdef ADC_VSERVO
 	[PX4IO_P_SETUP_VSERVO_SCALE]		= 10000,
 #else
@@ -194,14 +182,11 @@ volatile uint16_t	r_page_setup[] = {
 	[PX4IO_P_SETUP_THERMAL] = PX4IO_THERMAL_IGNORE
 };
 
-#ifdef CONFIG_ARCH_BOARD_PX4IO_V2
 #define PX4IO_P_SETUP_FEATURES_VALID	(PX4IO_P_SETUP_FEATURES_SBUS1_OUT | \
 		PX4IO_P_SETUP_FEATURES_SBUS2_OUT | \
 		PX4IO_P_SETUP_FEATURES_ADC_RSSI | \
 		PX4IO_P_SETUP_FEATURES_PWM_RSSI)
-#else
-#define PX4IO_P_SETUP_FEATURES_VALID	0
-#endif
+
 #define PX4IO_P_SETUP_ARMING_VALID	(PX4IO_P_SETUP_ARMING_FMU_ARMED | \
 		PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE_OK | \
 		PX4IO_P_SETUP_ARMING_INAIR_RESTART_OK | \
@@ -650,18 +635,6 @@ registers_set_one(uint8_t page, uint8_t offset, uint16_t value)
 			pwm_configure_rates(r_setup_pwm_rates, r_setup_pwm_defaultrate, value);
 			break;
 
-#ifdef CONFIG_ARCH_BOARD_PX4IO_V1
-
-		case PX4IO_P_SETUP_RELAYS:
-			value &= PX4IO_P_SETUP_RELAYS_VALID;
-			r_setup_relays = value;
-			POWER_RELAY1((value & PX4IO_P_SETUP_RELAYS_POWER1) ? 1 : 0);
-			POWER_RELAY2((value & PX4IO_P_SETUP_RELAYS_POWER2) ? 1 : 0);
-			POWER_ACC1((value & PX4IO_P_SETUP_RELAYS_ACC1) ? 1 : 0);
-			POWER_ACC2((value & PX4IO_P_SETUP_RELAYS_ACC2) ? 1 : 0);
-			break;
-#endif
-
 		case PX4IO_P_SETUP_VBATT_SCALE:
 			r_page_setup[PX4IO_P_SETUP_VBATT_SCALE] = value;
 			break;