diff --git a/main/ble.c b/main/ble.c
index eba7a83..a440a2b 100644
--- a/main/ble.c
+++ b/main/ble.c
@@ -198,13 +198,15 @@ static int svc_access_system(uint16_t conn_handle, uint16_t attr_handle, struct
 }
 
 static int barback_ble_char_access(uint16_t conn_handle, uint16_t attr_handle, struct ble_gatt_access_ctxt *ctxt, void *arg) {
-  uint16_t uuid16 = ble_uuid_u16(ctxt->chr->uuid);
-  uint8_t idx = uuid16 - (BLE_SERVICE_PUMP_ENABLED + 1);
+  uint16_t chr_uuid = ble_uuid_u16(ctxt->chr->uuid);
+
+  // match the UUID against 0b111
+  uint8_t idx = (chr_uuid & 0x07) - 1;
   uint8_t value = 0;
 
   barback_ble_access_t *access = (barback_ble_access_t *)arg;
 
-  ESP_LOGI(TAG, "conn_handle: %d	attr_handle: %d	char: 0x%02X	op: %s", conn_handle, attr_handle, uuid16, (ctxt->op == 0 ? "read" : ctxt->op == 1 ? "write" : "unknown"));
+  ESP_LOGI(TAG, "conn_handle: %d	attr_handle: %d	char: 0x%02X	op: %s", conn_handle, attr_handle, chr_uuid, (ctxt->op == 0 ? "read" : ctxt->op == 1 ? "write" : "unknown"));
 
   if(ctxt->op == BLE_GATT_ACCESS_OP_WRITE_CHR) {
     gatt_svr_chr_write(
@@ -216,24 +218,35 @@ static int barback_ble_char_access(uint16_t conn_handle, uint16_t attr_handle, s
 
     struct ble_gap_conn_desc notifiee;
 
+    // TODO
+    // this could needs to be verified, it might actually be needed
+    // NiBLE could be passing notifications itself on chr_handler changes
     for (uint16_t i = 0; i < CONFIG_NIMBLE_MAX_CONNECTIONS; i++) {
       if(ble_gap_conn_find(i, &notifiee) == ESP_OK) {
         ble_gattc_notify_custom(i, attr_handle, ctxt->om);
       }
     }
 
-    if(access->write != NULL)
+    if(access == NULL) {
+      ESP_LOGI(TAG, "no read/write functions defined");
+      return 0;
+    }
+
+    if(access->write != NULL) {
+      ESP_LOGI(TAG, "calling BLE write function: %d %d", idx, value);
+
       access->write(idx, value);
-  } else if(ctxt->op == BLE_GATT_ACCESS_OP_READ_CHR) {
+    }
+  } else if(access != NULL && ctxt->op == BLE_GATT_ACCESS_OP_READ_CHR) {
     if(access->read == NULL) {
       ESP_LOGW(TAG, "Attempted read without defining access.read");
       return 1;
     }
 
-    uint8_t enabled = access->read(idx);
+    uint8_t value = access->read(idx);
 
-    ESP_LOGI(TAG, "pumps_enabled[%d] = %d", idx, enabled);
-    os_mbuf_append(ctxt->om, &enabled, sizeof enabled);
+    ESP_LOGI(TAG, "returning read idx: %d value: %d", idx, value);
+    os_mbuf_append(ctxt->om, &value, sizeof value);
   }
 
   return 0;