diff --git a/Tools/AP_Periph/AP_Periph.cpp b/Tools/AP_Periph/AP_Periph.cpp
index 832868d75e..ce00b9e43e 100644
--- a/Tools/AP_Periph/AP_Periph.cpp
+++ b/Tools/AP_Periph/AP_Periph.cpp
@@ -61,8 +61,8 @@ void AP_Periph_FW::init()
 
     stm32_watchdog_pat();
 
-    hal.uartA->begin(AP_SERIALMANAGER_CONSOLE_BAUD, 32, 128);
-    hal.uartB->begin(115200, 32, 128);
+    hal.uartA->begin(AP_SERIALMANAGER_CONSOLE_BAUD, 32, 32);
+    hal.uartB->begin(115200, 128, 256);
 
     load_parameters();
 
diff --git a/Tools/AP_Periph/can.cpp b/Tools/AP_Periph/can.cpp
index 85bed2cf3f..92efcb7406 100644
--- a/Tools/AP_Periph/can.cpp
+++ b/Tools/AP_Periph/can.cpp
@@ -55,8 +55,12 @@
 extern const AP_HAL::HAL &hal;
 extern AP_Periph_FW periph;
 
+#ifndef HAL_CAN_POOL_SIZE
+#define HAL_CAN_POOL_SIZE 4000
+#endif
+
 static CanardInstance canard;
-static uint32_t canard_memory_pool[3000/4];
+static uint32_t canard_memory_pool[HAL_CAN_POOL_SIZE/sizeof(uint32_t)];
 #ifndef HAL_CAN_DEFAULT_NODE_ID
 #define HAL_CAN_DEFAULT_NODE_ID CANARD_BROADCAST_NODE_ID
 #endif
@@ -67,6 +71,10 @@ static uint8_t transfer_id;
 #define CAN_APP_NODE_NAME                                               "org.ardupilot.ap_periph"
 #endif
 
+#ifndef CAN_PROBE_CONTINUOUS
+#define CAN_PROBE_CONTINUOUS 0
+#endif
+
 /*
  * Variables used for dynamic node ID allocation.
  * RTFM at http://uavcan.org/Specification/6._Application_level_functions/#dynamic-node-id-allocation
@@ -788,7 +796,7 @@ static void processTx(void)
     }
 }
 
-static ObjectBuffer<CANRxFrame> rxbuffer{16};
+static ObjectBuffer<CANRxFrame> rxbuffer{32};
 
 static void can_rxfull_cb(CANDriver *canp, uint32_t flags)
 {
@@ -1061,7 +1069,7 @@ void AP_Periph_FW::can_mag_update(void)
 {
 #ifdef HAL_PERIPH_ENABLE_MAG
     compass.read();
-#if 1
+#if CAN_PROBE_CONTINUOUS
     if (compass.get_count() == 0) {
         static uint32_t last_probe_ms;
         uint32_t now = AP_HAL::millis();
@@ -1279,6 +1287,7 @@ void AP_Periph_FW::can_baro_update(void)
 void AP_Periph_FW::can_airspeed_update(void)
 {
 #ifdef HAL_PERIPH_ENABLE_AIRSPEED
+#if CAN_PROBE_CONTINUOUS
     if (!airspeed.healthy()) {
         uint32_t now = AP_HAL::millis();
         static uint32_t last_probe_ms;
@@ -1287,6 +1296,7 @@ void AP_Periph_FW::can_airspeed_update(void)
             airspeed.init();
         }
     }
+#endif
     uint32_t now = AP_HAL::millis();
     if (now - last_airspeed_update_ms < 50) {
         // max 20Hz data