diff --git a/src/common/mode_config.h b/src/common/mode_config.h
index c514117..93249e7 100644
--- a/src/common/mode_config.h
+++ b/src/common/mode_config.h
@@ -98,6 +98,7 @@ typedef struct {
 	uint8_t dev_polarity;
 	uint8_t dev_phase;
 	uint8_t dev_bit_lsb_msb;
+	uint8_t dev_bidir;
 } spi_config_t;
 
 typedef struct {
diff --git a/src/drv/stm32cube/bsp_spi.c b/src/drv/stm32cube/bsp_spi.c
index f9a1ca1..24dbfca 100644
--- a/src/drv/stm32cube/bsp_spi.c
+++ b/src/drv/stm32cube/bsp_spi.c
@@ -186,7 +186,12 @@ bsp_status_t bsp_spi_init(bsp_dev_spi_t dev_num, mode_config_proto_t* mode_conf)
 	/* SW NSS user shall call bsp_spi_select()/bsp_spi_unselect() */
 	hspi->Init.NSS = SPI_NSS_SOFT;
 	hspi->Init.BaudRatePrescaler = ((7 - mode_conf->config.spi.dev_speed) * SPI_CR1_BR_0);
-	hspi->Init.Direction = SPI_DIRECTION_2LINES;
+	/* Half-duplex / bidirectional or normal 2-line */
+	if(mode_conf->config.spi.dev_bidir == 0) {
+		hspi->Init.Direction = SPI_DIRECTION_2LINES;
+	} else {
+		hspi->Init.Direction = SPI_DIRECTION_1LINE;
+	}
 
 	if(mode_conf->config.spi.dev_phase == 0)
 		cpha = SPI_PHASE_1EDGE;
@@ -221,6 +226,11 @@ bsp_status_t bsp_spi_init(bsp_dev_spi_t dev_num, mode_config_proto_t* mode_conf)
 	/* Enable SPI peripheral */
 	__HAL_SPI_ENABLE(hspi);
 
+	/* Enable TX mode to avoid spurious clock output */
+	if(mode_conf->config.spi.dev_bidir == 1) {
+		SPI_1LINE_TX(hspi);
+	}
+
 	return status;
 }
 
@@ -351,9 +361,21 @@ bsp_status_t bsp_spi_write_read_u8(bsp_dev_spi_t dev_num, uint8_t* tx_data, uint
 	hspi = &spi_handle[dev_num];
 
 	bsp_status_t status;
-	status = (bsp_status_t) HAL_SPI_TransmitReceive(hspi, tx_data, rx_data, nb_data, SPIx_TIMEOUT_MAX);
-	if(status != BSP_OK) {
-		spi_error(dev_num);
+	if(hspi->Init.Direction == SPI_DIRECTION_1LINE) {
+		status = (bsp_status_t) HAL_SPI_Transmit(hspi, tx_data, nb_data, SPIx_TIMEOUT_MAX);
+		if(status != BSP_OK) {
+			spi_error(dev_num);
+			return status;
+		}
+		status = (bsp_status_t) HAL_SPI_Receive(hspi, rx_data, nb_data, SPIx_TIMEOUT_MAX);
+		if(status != BSP_OK) {
+			spi_error(dev_num);
+		}
+	} else {
+		status = (bsp_status_t) HAL_SPI_TransmitReceive(hspi, tx_data, rx_data, nb_data, SPIx_TIMEOUT_MAX);
+		if(status != BSP_OK) {
+			spi_error(dev_num);
+		}
 	}
 	return status;
 }
diff --git a/src/hydrabus/commands.c b/src/hydrabus/commands.c
index 8cc29db..575e036 100644
--- a/src/hydrabus/commands.c
+++ b/src/hydrabus/commands.c
@@ -168,6 +168,7 @@ const t_token_dict tl_dict[] = {
 	{ T_POKE, "poke" },
 	{ T_SWIO, "swio" },
 	{ T_CONTINUITY, "continuity" },
+	{ T_BIDIR, "bidir" },
 	/* Developer warning add new command(s) here */
 
 	/* BP-compatible commands */
@@ -1065,7 +1066,10 @@ t_token tokens_i2c[] = {
 	{ T_MSB_FIRST, \
 		.help = "Send/receive MSB first" }, \
 	{ T_LSB_FIRST, \
-		.help = "Send/receive LSB first" },
+		.help = "Send/receive LSB first" }, \
+	{ T_BIDIR, \
+		.arg_type = T_ARG_UINT, \
+		.help = "Bidir mode (0/1)" }, \
 
 t_token tokens_mode_spi[] = {
 	{
diff --git a/src/hydrabus/commands.h b/src/hydrabus/commands.h
index 46bdefd..996b977 100644
--- a/src/hydrabus/commands.h
+++ b/src/hydrabus/commands.h
@@ -160,6 +160,7 @@ enum {
 	T_POKE,
 	T_SWIO,
 	T_CONTINUITY,
+	T_BIDIR,
 	/* Developer warning add new command(s) here */
 
 	/* BP-compatible commands */
diff --git a/src/hydrabus/hydrabus_bbio_spi.c b/src/hydrabus/hydrabus_bbio_spi.c
index fc2fc99..32321a3 100644
--- a/src/hydrabus/hydrabus_bbio_spi.c
+++ b/src/hydrabus/hydrabus_bbio_spi.c
@@ -302,6 +302,9 @@ void bbio_mode_spi(t_hydra_console *con)
 					} else {
 						bsp_spi_select(proto->dev_num);
 					}
+					//Set bidir mode
+					proto->config.spi.dev_bidir = (bbio_subcommand & 0b100)?1:0;
+
 					//Set AUX[0] (PC4) value
 					bbio_aux_write((bbio_subcommand & 0b10)>>1);
 
diff --git a/src/hydrabus/hydrabus_mode_spi.c b/src/hydrabus/hydrabus_mode_spi.c
index f546ad1..3ee1c52 100644
--- a/src/hydrabus/hydrabus_mode_spi.c
+++ b/src/hydrabus/hydrabus_mode_spi.c
@@ -26,10 +26,16 @@ static int exec(t_hydra_console *con, t_tokenline_parsed *p, int token_pos);
 static int show(t_hydra_console *con, t_tokenline_parsed *p);
 
 static const char* str_pins_spi1= {
-	"CS:   PA15\r\nSCK:  PB3\r\nMISO: PB4\r\nMOSI: PB5\r\n"
+	"CS:   PA15\r\nSCK:  PB3\r\n"
 };
 static const char* str_pins_spi2= {
-	"CS:   PC1 (SW)\r\nSCK:  PB10\r\nMISO: PC2\r\nMOSI: PC3\r\n"
+	"CS:   PC1 (SW)\r\nSCK:  PB10\r\n"
+};
+static const char* str_pins_spi1_io= {
+	"MISO: PB4\r\nMOSI: PB5\r\n"
+};
+static const char* str_pins_spi2_io= {
+	"MISO: PC2\r\nMOSI: PC3\r\n"
 };
 static const char* str_prompt_spi1= { "spi1" PROMPT };
 static const char* str_prompt_spi2= { "spi2" PROMPT };
@@ -75,6 +81,7 @@ static void init_proto_default(t_hydra_console *con)
 	proto->config.spi.dev_polarity = 0;
 	proto->config.spi.dev_phase = 0;
 	proto->config.spi.dev_bit_lsb_msb = DEV_FIRSTBIT_MSB;
+	proto->config.spi.dev_bidir = 0;
 }
 
 static void show_params(t_hydra_console *con)
@@ -82,13 +89,14 @@ static void show_params(t_hydra_console *con)
 	uint8_t i, cnt;
 	mode_config_proto_t* proto = &con->mode->proto;
 
-	cprintf(con, "Device: SPI%d\r\nGPIO resistor: %s\r\nMode: %s\r\n"
+	cprintf(con, "Device: SPI%d\r\nGPIO resistor: %s\r\nMode: %s\r\nBidir: %s\r\n"
 		"Frequency: ",
 		proto->dev_num + 1,
 		proto->config.spi.dev_gpio_pull == MODE_CONFIG_DEV_GPIO_PULLUP ? "pull-up" :
 		proto->config.spi.dev_gpio_pull == MODE_CONFIG_DEV_GPIO_PULLDOWN ? "pull-down" :
 		"floating",
-		proto->config.spi.dev_mode == DEV_MASTER ? "master" : "slave");
+		proto->config.spi.dev_mode == DEV_MASTER ? "master" : "slave",
+		proto->config.spi.dev_bidir == 0 ? "off" : "on");
 
 	print_freq(con, spi_speeds[proto->dev_num][proto->config.spi.dev_speed]);
 	cprintf(con, " (");
@@ -242,6 +250,17 @@ static int exec(t_hydra_console *con, t_tokenline_parsed *p, int token_pos)
 				return t;
 			}
 			break;
+		case T_BIDIR:
+			/* Integer parameter. */
+			t += 2;
+			memcpy(&arg_int, p->buf + p->tokens[t], sizeof(int));
+			if (arg_int > 1 ) {
+				cprintf(con, "Bidir must be 0 or 1.\r\n");
+				return t;
+			}
+			proto->config.spi.dev_bidir = arg_int;
+			bsp_spi_init(proto->dev_num, proto);
+			break;
 		default:
 			return t - token_pos;
 		}
@@ -357,10 +376,21 @@ static int show(t_hydra_console *con, t_tokenline_parsed *p)
 	tokens_used = 0;
 	if (p->tokens[1] == T_PINS) {
 		tokens_used++;
-		if (proto->dev_num == 0)
+		if (proto->dev_num == 0) {
 			cprint(con, str_pins_spi1, strlen(str_pins_spi1));
-		else
+			if (proto->config.spi.dev_bidir == 0) {
+				cprint(con, str_pins_spi1_io, strlen(str_pins_spi1_io));
+			} else {
+				cprintf(con, "IO:   %s\r\n", proto->config.spi.dev_mode == DEV_MASTER ? "PB5" : "PB4");
+			}
+		} else {
 			cprint(con, str_pins_spi2, strlen(str_pins_spi2));
+			if (proto->config.spi.dev_bidir == 0) {
+				cprint(con, str_pins_spi2_io, strlen(str_pins_spi2_io));
+			} else {
+				cprintf(con, "IO:   %s\r\n", proto->config.spi.dev_mode == DEV_MASTER ? "PC3" : "PC2");
+			}
+		}
 	} else {
 		show_params(con);
 	}
diff --git a/src/hydrabus/hydrabus_serprog.c b/src/hydrabus/hydrabus_serprog.c
index b4e7f91..02919be 100644
--- a/src/hydrabus/hydrabus_serprog.c
+++ b/src/hydrabus/hydrabus_serprog.c
@@ -37,6 +37,7 @@ void bbio_serprog_init_proto_default(t_hydra_console *con)
 	proto->config.spi.dev_polarity = 0;
 	proto->config.spi.dev_phase = 0;
 	proto->config.spi.dev_bit_lsb_msb = DEV_FIRSTBIT_MSB;
+	proto->config.spi.dev_bidir = 0;
 }
 
 void bbio_mode_serprog(t_hydra_console *con)