diff --git a/project/Giomba/Makefile b/project/Giomba/Makefile
index 7af95bd48..a0f4d2c20 100644
--- a/project/Giomba/Makefile
+++ b/project/Giomba/Makefile
@@ -1,5 +1,5 @@
 CONTIKI_PROJECT = cart
-PROJECT_SOURCEFILES += sendrecv.c status.c
+PROJECT_SOURCEFILES += sendrecv.c status.c batmon.c leds.cart.c
 PLATFORMS_ONLY = cc26x0-cc13x0
 
 all: $(CONTIKI_PROJECT)
diff --git a/project/Giomba/batmon.c b/project/Giomba/batmon.c
new file mode 100644
index 000000000..92e606b3e
--- /dev/null
+++ b/project/Giomba/batmon.c
@@ -0,0 +1,34 @@
+#include "batmon.h"
+
+void batmon(void) {
+
+    /* read battery monitor sensor -- hey where's the battery? */
+    /* actually this is a simulation, isn't it? =) */
+
+    switch (status) {
+        /* charge */
+        case NOT_ASSOCIATED:
+        case ASSOCIATED:
+            battery_charge += 5;
+            if (battery_charge > 100) battery_charge = 100;
+            led_heartbeat(NULL);
+        break;
+
+        /* discharge */
+        default:
+            battery_charge -= 1;
+            if (battery_charge < 0) battery_charge = 0;
+        break;
+    }
+
+    /* turn on red led if battery charge is low */
+    if (battery_charge < 48) {  /* TODO */
+        leds_on(LEDS_RED);
+    } else {
+        leds_off(LEDS_RED);
+    }
+
+    etimer_reset(&battery_timer);
+
+    printf("[I] updated battery status: %d %%\n", battery_charge);
+}
diff --git a/project/Giomba/batmon.h b/project/Giomba/batmon.h
new file mode 100644
index 000000000..ab4ea93cb
--- /dev/null
+++ b/project/Giomba/batmon.h
@@ -0,0 +1,9 @@
+#ifndef BATMON_H
+#define BATMON_H
+
+#include "leds.cart.h"
+#include "status.h"
+
+void batmon(void);
+
+#endif
diff --git a/project/Giomba/cart.c b/project/Giomba/cart.c
index 3bb1bf108..6b6513009 100644
--- a/project/Giomba/cart.c
+++ b/project/Giomba/cart.c
@@ -1,29 +1,26 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "os/dev/leds.h"
-#include "batmon-sensor.h"
-
 #include "../common/supermarket_net.h"
+#include "batmon.h"
 #include "event.h"
 #include "log.h"
 #include "sendrecv.h"
 #include "status.h"
 
-//static linkaddr_t destination_address = {{ 0x00, 0x12, 0x4b, 0x00, 0x0f, 0x8f, 0x18, 0x11 }};
-
 PROCESS(cart_main_process, "Cart Process");
 AUTOSTART_PROCESSES(&cart_main_process);
 
 PROCESS_THREAD(cart_main_process, ev, data) {
 	PROCESS_BEGIN();
-    //	SENSORS_ACTIVATE(batmon_sensor);
 
     /*** Variables initialization ***/
-    // status = NOT_ASSOCIATED; // TODO DEBUG
-    status = SHOPPING;
+    status = NOT_ASSOCIATED; // TODO DEBUG
+    //status = SHOPPING;
 
-    etimer_set(&broadcast_timer, 5 * CLOCK_SECOND);
+    /*** Timer initialization ***/
+    etimer_set(&assigner_timer, 5 * CLOCK_SECOND);
+    etimer_set(&battery_timer, 10 * CLOCK_SECOND);
 
     /*** Subsystem initialization ***/
     net_init();
@@ -34,6 +31,8 @@ PROCESS_THREAD(cart_main_process, ev, data) {
 	while (true) {
         PROCESS_WAIT_EVENT();
 
+        if (ev == PROCESS_EVENT_TIMER && etimer_expired(&battery_timer)) batmon();
+
 		switch(status) {
 			case NOT_ASSOCIATED: s_not_associated(ev, data); break;
 			case ASSOCIATED: s_associated(ev, data); break;
diff --git a/project/Giomba/leds.cart.c b/project/Giomba/leds.cart.c
new file mode 100644
index 000000000..43e2f3a17
--- /dev/null
+++ b/project/Giomba/leds.cart.c
@@ -0,0 +1,29 @@
+#include "leds.cart.h"
+
+void led_blink(void* ptr) {
+    printf("[I] led blink\n");
+    if (! (leds_get() & LEDS_GREEN)) {
+        leds_on(LEDS_GREEN);
+        ctimer_set(&led_timer, CLOCK_SECOND, led_blink, NULL);
+    } else {
+        leds_off(LEDS_GREEN);
+    }
+    return;
+}
+
+
+void led_heartbeat(void* ptr) {
+    printf("[I] led heartbeat\n");
+
+/*
+    static uint8_t times = 4;
+
+    if (times == 4) leds_off(LEDS_GREEN);
+    if (--times != 0) {
+        leds_toggle(LEDS_GREEN);
+        ctimer_set(&led_timer, 20, led_heartbeat, NULL);
+    } else {
+        times = 4;
+    }
+*/
+}
diff --git a/project/Giomba/leds.cart.h b/project/Giomba/leds.cart.h
new file mode 100644
index 000000000..f2db7353b
--- /dev/null
+++ b/project/Giomba/leds.cart.h
@@ -0,0 +1,10 @@
+#ifndef LEDS_CART_H
+#define LEDS_CART_H
+
+#include "status.h"
+#include "os/dev/leds.h"
+
+void led_blink(void*);
+void led_heartbeat(void*);
+
+#endif
diff --git a/project/Giomba/sendrecv.c b/project/Giomba/sendrecv.c
index 32a633804..a296d43ed 100644
--- a/project/Giomba/sendrecv.c
+++ b/project/Giomba/sendrecv.c
@@ -58,6 +58,7 @@ void net_recv(const void* data, uint16_t len, const linkaddr_t* src, const linka
 }
 
 void net_send(const void* data, uint16_t len, const linkaddr_t* dst) {
+    printf("[I] sending msg type %d\n", ((msg*)data)->msg_type);
     memcpy(net_buffer, data, len);
     nullnet_len = len;
     NETSTACK_NETWORK.output(dst);
diff --git a/project/Giomba/status.c b/project/Giomba/status.c
index 5eb3bc09e..7b793d967 100644
--- a/project/Giomba/status.c
+++ b/project/Giomba/status.c
@@ -3,7 +3,10 @@
 #define MAX_PRODUCT 20
 
 enum CartStatus status;
-struct etimer broadcast_timer;
+struct etimer assigner_timer;   /* timer to periodically make a report to the assigner */
+struct etimer battery_timer;    /* timer to periodically read battery status */
+struct ctimer led_timer;        /* timer to shortly blink leds */
+int8_t battery_charge = 50;
 linkaddr_t assigner_address;
 linkaddr_t cash_address;
 uint32_t customer_id = 1234;
@@ -16,20 +19,24 @@ product_t list[MAX_PRODUCT];
 void s_not_associated(process_event_t ev, process_data_t data) {
     if (ev == PROCESS_EVENT_TIMER) {
         /* at time expiration, send broadcast message to request association with assigner */
-        if (etimer_expired(&broadcast_timer)) {
+        if (etimer_expired(&assigner_timer)) {
             printf("[I] Sending association request msg\n");
             msg m;
             m.msg_type = ASSOCIATION_REQUEST_MSG;
             net_send(&m, sizeof(m), NULL);
-            etimer_reset(&broadcast_timer);
+            etimer_reset(&assigner_timer);
         }
     }
     else    /* if a msg is received from network and represents an association event, then associate */
     if (ev == PROCESS_EVENT_MSG && event == CART_EVENT_ASSOCIATED) {
         printf("[I] Associated with Assigner\n");
+
         assigner_address = pkt.src;
         nprod = 0;
         status = ASSOCIATED;
+
+        /* blink led */
+        led_blink(NULL);
     }
 }
 
@@ -39,14 +46,15 @@ void s_associated(process_event_t ev, process_data_t data) {
         printf("[I] Sending battery level\n");
         struct battery_msg m;
         m.msg_type = BATTERY_STATUS_MSG;
-        m.battery_percentage = 77;
+        m.battery_percentage = battery_charge;
         net_send(&m, sizeof(m), &assigner_address);
-        etimer_reset(&broadcast_timer);
+        etimer_reset(&assigner_timer);
     }
     if (ev == PROCESS_EVENT_MSG && event == CART_EVENT_ASSIGNED) {
         /* cart has been assigned to a new customer */
         customer_id = ((assign_msg*)pkt.data)->customer_id;
         printf("[I] Assigned to customer id %d\n", (int)customer_id);
+        leds_on(LEDS_GREEN);
         status = SHOPPING;
     }
 }
@@ -84,6 +92,7 @@ void s_shopping(process_event_t ev, process_data_t data) {
     }
     if (ev == button_hal_release_event) {   /* any button will do */
         /* ask product to send items to me */
+        printf("[I] Dear product Launchpad, please send items to me\n");
         msg m;
         m.msg_type = START_SHOPPING_MSG;
         net_send(&m, sizeof(m), NULL);
@@ -135,9 +144,10 @@ void s_cash_out_send_list(process_event_t ev, process_data_t data) {
         memset(&cash_address, 0, sizeof(cash_address));
 
         printf("[I] List END. Go back to ASSOCIATED status\n");
-        etimer_restart(&broadcast_timer);
-        // status = ASSOCIATED; // TODO DEBUG
-        status = SHOPPING;
+        etimer_restart(&assigner_timer);
+        leds_off(LEDS_GREEN);
+        status = ASSOCIATED;
+        // status = SHOPPING; // TODO DEBUG
     }
 
 }
diff --git a/project/Giomba/status.h b/project/Giomba/status.h
index 27915b340..b7d10f862 100644
--- a/project/Giomba/status.h
+++ b/project/Giomba/status.h
@@ -6,9 +6,11 @@
 #include "sys/process.h"
 
 #include "os/dev/button-hal.h"
+#include "batmon-sensor.h"
 
 #include "../common/supermarket_net.h"
 #include "event.h"
+#include "leds.cart.h"
 #include "sendrecv.h"
 
 enum CartStatus {
@@ -20,7 +22,11 @@ enum CartStatus {
 };
 
 extern enum CartStatus status;
-extern struct etimer broadcast_timer;
+extern struct etimer assigner_timer;
+extern struct etimer battery_timer;
+extern struct ctimer led_timer;
+
+extern int8_t battery_charge;
 
 void s_not_associated(process_event_t ev, process_data_t data);
 void s_associated(process_event_t ev, process_data_t data);
diff --git a/project/product/product.c b/project/product/product.c
index c441697f7..820edad84 100644
--- a/project/product/product.c
+++ b/project/product/product.c
@@ -17,7 +17,7 @@
 #define LOG_LEVEL LOG_LEVEL_INFO
 
 /* MAC Address for cart -- This emulates the RFID tag */
-static linkaddr_t dest_addr = {{0x00, 0x12, 0x4b, 0x00, 0x0f, 0x82, 0x00, 0x04}};
+static linkaddr_t dest_addr = {{0xca, 0xfe, 0xba, 0xbe, 0xde, 0xad, 0xbe, 0xef}};
 
 product_t product_list[] = {
 	{ 1, "21/12/19", 105 },