diff --git a/include/led7seg.h b/include/led7seg.h
index fae28ec..39c4bb5 100644
--- a/include/led7seg.h
+++ b/include/led7seg.h
@@ -11,6 +11,7 @@ struct st_7seg {
     int digit;
     int bit;
     uint16_t datagram;
+    uint8_t buttons;
 };
 
 
diff --git a/include/proto.h b/include/proto.h
index 81ea7a5..b7abca9 100644
--- a/include/proto.h
+++ b/include/proto.h
@@ -5,8 +5,8 @@
 #include <serial.h>
 
 
-#define PROTO_RESPONSE_TIMEOUT_MS 20
-#define PROTO_UPDATE_INTERVAL_MS 200
+#define PROTO_RESPONSE_TIMEOUT_MS 5
+#define PROTO_UPDATE_INTERVAL_MS 50
 
 
 enum proto_fsm {
diff --git a/src/led7seg.c b/src/led7seg.c
index 6dad765..ac86c73 100644
--- a/src/led7seg.c
+++ b/src/led7seg.c
@@ -11,14 +11,14 @@ int bt_inputs() {
     bool bt1 = !!(GPIOB->IDR & (1<<1));
     bool bt2 = !!(GPIOB->IDR & (1<<0));
     bool bt3 = !!(GPIOB->IDR & (1<<12));
-    bool bt4 = !!(GPIOB->IDR & (1<<4));
+    bool bt4 = !!(GPIOB->IDR & (1<<3));
     bool bt5 = !!(GPIOA->IDR & (1<<15));
     return (bt5<<5) | (bt4<<4) | (bt3<<3) | (bt2<<2) | (bt1<<1) | (bt0<<0);
 }
 
 void init_7seg() {
     GPIOA->MODER |= OUT(15);
-    GPIOB->MODER |= OUT(12) | OUT(3);
+    GPIOB->MODER |= OUT(12) | OUT(3) | OUT(2);
     GPIOA->BRR = (1<<15);
     GPIOB->BRR = (1<<12) | (1<<3);
     memset(&st_7seg, 0, sizeof(st_7seg));
@@ -122,32 +122,42 @@ static uint8_t led7seg_font_lut[] = {
 void step_7seg() {
     GPIOA->BSRR = BSRR_CLEAR(15);
 
-    if (st_7seg.bit&1) {
-        GPIOB->BSRR = BSRR_SET(3);
-        st_7seg.datagram <<= 1; 
-    } else {
-        GPIOB->BSRR = BSRR_VALUE(12, st_7seg.datagram&0x8000) | BSRR_CLEAR(3);
+    if (st_7seg.bit < 16*2) {
+        if (st_7seg.bit&1) {
+            GPIOB->BSRR = BSRR_SET(3);
+            st_7seg.datagram <<= 1; 
+        } else {
+            GPIOB->BSRR = BSRR_VALUE(12, st_7seg.datagram&0x8000) | BSRR_CLEAR(3);
+        }
     }
 
     st_7seg.bit++;
-    if (st_7seg.bit == 16*2) {
-        st_7seg.bit = 0;
+    if (st_7seg.bit >= 16*2) {
+        if (st_7seg.bit == 16*2+1) {
+            st_7seg.bit = 0;
+            st_7seg.buttons = bt_inputs();
+            GPIOB->BSRR = (1<<2); /* Disable buttons */
+            GPIOB->MODER |= OUT(3) | OUT(12);
 
-        st_7seg.module++;
-        if (st_7seg.module == 3) {
-            st_7seg.module = 0;
-            GPIOA->BSRR = BSRR_SET(15);
+            st_7seg.module++;
+            if (st_7seg.module == 3) {
+                st_7seg.module = 0;
+                GPIOA->BSRR = BSRR_SET(15);
 
-            st_7seg.digit++;
-            if (st_7seg.digit == 8) {
-                st_7seg.digit = 0;
+                st_7seg.digit++;
+                if (st_7seg.digit == 8) {
+                    st_7seg.digit = 0;
+                }
             }
+            
+            uint8_t dp = (st_7seg.dp[st_7seg.module] & (1<<st_7seg.digit)) ? 0x80 : 0x00;
+            st_7seg.datagram = ((st_7seg.digit+1)<<8) |
+                led7seg_font_lut[st_7seg.data[st_7seg.module][st_7seg.digit]] |
+                dp;
+        } else {
+            GPIOB->BRR = (1<<2); /* Enable buttons */
+            GPIOB->MODER &= ~(CLEAR(3) | CLEAR(12));
         }
-        
-        uint8_t dp = (st_7seg.dp[st_7seg.module] & (1<<st_7seg.digit)) ? 0x80 : 0x00;
-        st_7seg.datagram = ((st_7seg.digit+1)<<8) |
-            led7seg_font_lut[st_7seg.data[st_7seg.module][st_7seg.digit]] |
-            dp;
     }
 }
 
diff --git a/src/main.c b/src/main.c
index bcb2af9..aa4ee44 100644
--- a/src/main.c
+++ b/src/main.c
@@ -150,7 +150,9 @@ int main(void) {
                      (3<<GPIO_OSPEEDR_OSPEEDR15_Pos);
     GPIOB->PUPDR |= PULLUP(0) | /* BT2 */
                     PULLUP(1) | /* BT1 */
-                    PULLUP(2);  /* BT0 */
+                    PULLUP(2) | /* BT0 */
+                    PULLUP(3) | /* BT4 */
+                    PULLUP(12); /* BT3 */
     GPIOB->OTYPER = (1<<12) | (1<<3);
 
     /* GPIOC:
@@ -161,11 +163,12 @@ int main(void) {
 
     led_init();
     led_set_global_brightness(2);
-    adc_init();
     lcd_init();
 
     if (st_lcd.has_lcd) {
-        uart_dma_init(USART3, DMA1_Channel7, BADDR_DISPLAY);
+        SYSCFG->CFGR1 |= SYSCFG_CFGR1_USART3_DMA_RMP;
+        uart_dma_init(USART3, DMA1_Channel2, BADDR_DISPLAY);
+
         const char *lines[4] = {"Display initialized ",
                                 "                    ",
                                 "Waiting for         ",
@@ -183,6 +186,8 @@ int main(void) {
         blank_7seg(2);
 
     } else {
+        adc_init();
+
         int bt = bt_inputs();
         if (bt&1) {
             uart_dma_init(USART3, DMA1_Channel7, BADDR_MOTOR);
diff --git a/src/proto.c b/src/proto.c
index 32c409d..9e84e2b 100644
--- a/src/proto.c
+++ b/src/proto.c
@@ -1,6 +1,7 @@
 
 #include <proto.h>
 #include <adc.h>
+#include <led7seg.h>
 
 static void tx_time_sync(void);
 static ErrorCode tx_fetch_adc(int index);
@@ -8,6 +9,7 @@ static void proto_handle_host(bool timeout);
 static void proto_update_lcd_strings(void);
 static ErrorCode tx_update_display(void);
 static void tx_adc_data(void);
+static void tx_button_state(void);
 
 
 struct proto_state st_proto;
@@ -55,7 +57,7 @@ void uart_handle_user_packet(struct ll_pkt *pkt, size_t len) {
         
     } else if (board_config == BCFG_DISPLAY) {
         if (pkt->type == PK_DISPLAY_UPDATE) {
-            /* ... */
+            tx_button_state();
         }
     } else if (board_config == BCFG_MEAS) {
         if (pkt->type == PK_FETCH_ADC) {
@@ -114,7 +116,7 @@ void tx_adc_data() {
             .src = uart_st.addr,
             .dst = SER_ADDR_BROADCAST,
             .pid = 0,
-            .type = PK_TIME_SYNC,
+            .type = PK_FETCH_RESPONSE,
         },
         .timestamp = sync_time_us,
         .sampling_interval_us = st_adc.sampling_interval_us,
@@ -148,6 +150,24 @@ void tx_adc_data() {
     }
 }
 
+void tx_button_state() {
+    struct pkt_button_state pk = {
+        .ll_pkt = {
+            .src = uart_st.addr,
+            .dst = SER_ADDR_BROADCAST,
+            .pid = 0,
+            .type = PK_BUTTON_STATE,
+        },
+        .buttons = st_7seg.buttons,
+    };
+
+    ErrorCode rc = uart_send_packet_nonblocking(&pk.ll_pkt, sizeof(pk));
+    if (rc) {
+        st_proto.error = rc;
+        st_proto.last_error = sys_time_us;
+    }
+}
+
 void tx_time_sync() {
     struct pkt_time_sync pk = {
         .ll_pkt = {