Bluetooth: Enable CI central_hr/peripheral_hr on bbc_microbit

Building for this target ensures we keep in mind resource-constrained
microcontrollers when making changes in Bluetooth.

Signed-off-by: Jonathan Rico <jonathan.rico@nordicsemi.no>

samples/bluetooth/central_hr/prj_minimal.conf

@@ -0,0 +1,103 @@
+CONFIG_BT=y
+CONFIG_BT_SMP=y
+CONFIG_BT_CENTRAL=y
+
+# Drivers and peripherals
+CONFIG_I2C=n
+CONFIG_WATCHDOG=n
+CONFIG_PINCTRL=n
+CONFIG_SPI=n
+CONFIG_GPIO=n
+CONFIG_SERIAL=n
+
+# Power management
+CONFIG_PM=n
+
+# Interrupts
+CONFIG_DYNAMIC_INTERRUPTS=n
+CONFIG_IRQ_OFFLOAD=n
+
+# Memory protection
+CONFIG_THREAD_STACK_INFO=n
+CONFIG_THREAD_CUSTOM_DATA=n
+CONFIG_FPU=n
+
+# Boot
+CONFIG_BOOT_BANNER=n
+CONFIG_BOOT_DELAY=0
+
+# Console
+CONFIG_CONSOLE=n
+CONFIG_UART_CONSOLE=n
+CONFIG_STDOUT_CONSOLE=n
+CONFIG_PRINTK=n
+CONFIG_EARLY_CONSOLE=n
+
+# Build
+CONFIG_SIZE_OPTIMIZATIONS=y
+
+# ARM
+CONFIG_ARM_MPU=n
+
+# In order to correctly tune the stack sizes for the threads the following
+# Configurations can enabled to print the current use:
+# CONFIG_THREAD_NAME=y
+# CONFIG_THREAD_ANALYZER=y
+# CONFIG_THREAD_ANALYZER_AUTO=y
+# CONFIG_THREAD_ANALYZER_RUN_UNLOCKED=y
+# CONFIG_THREAD_ANALYZER_USE_PRINTK=y
+# CONFIG_THREAD_ANALYZER_AUTO_INTERVAL=20
+# CONFIG_CONSOLE=y
+# CONFIG_UART_CONSOLE=y
+# CONFIG_SERIAL=y
+# CONFIG_PRINTK=y
+
+# Example output of thread analyzer
+# BT RX               : STACK: unused 576 usage 448 / 1024 (43 %); CPU: 0 %
+# BT RX pri           : STACK: unused 260 usage 188 / 448 (41 %); CPU: 0 %
+# BT ECC              : STACK: unused 256 usage 888 / 1144 (77 %); CPU: 1 %
+# BT TX               : STACK: unused 296 usage 344 / 640 (53 %); CPU: 0 %
+# thread_analyzer     : STACK: unused 128 usage 384 / 512 (75 %); CPU: 1 %
+# sysworkq            : STACK: unused 856 usage 168 / 1024 (16 %); CPU: 0 %
+# logging             : STACK: unused 232 usage 536 / 768 (69 %); CPU: 0 %
+# idle 00             : STACK: unused 208 usage 48 / 256 (18 %); CPU: 97 %
+# main                : STACK: unused 576 usage 448 / 1024 (43 %); CPU: 0 %
+CONFIG_BT_RX_STACK_SIZE=1024
+CONFIG_BT_HCI_TX_STACK_SIZE_WITH_PROMPT=y
+CONFIG_BT_HCI_TX_STACK_SIZE=640
+CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=512
+CONFIG_IDLE_STACK_SIZE=128
+CONFIG_MAIN_STACK_SIZE=640
+CONFIG_ISR_STACK_SIZE=1024
+
+# Disable features not needed
+CONFIG_TIMESLICING=n
+CONFIG_COMMON_LIBC_MALLOC=n
+CONFIG_LOG=n
+CONFIG_ASSERT=n
+
+# Disable Bluetooth features not needed
+# CONFIG_BT_DEBUG_NONE=y
+CONFIG_BT_ASSERT=n
+CONFIG_BT_DATA_LEN_UPDATE=n
+CONFIG_BT_PHY_UPDATE=n
+CONFIG_BT_GATT_CACHING=n
+CONFIG_BT_GATT_SERVICE_CHANGED=n
+CONFIG_BT_GAP_PERIPHERAL_PREF_PARAMS=n
+CONFIG_BT_SETTINGS_CCC_LAZY_LOADING=y
+CONFIG_BT_HCI_VS=n
+
+# Disable Bluetooth controller features not needed
+CONFIG_BT_CTLR_PRIVACY=n
+CONFIG_BT_CTLR_PHY_2M=n
+
+# Reduce Bluetooth buffers
+CONFIG_BT_BUF_EVT_DISCARDABLE_COUNT=1
+CONFIG_BT_BUF_EVT_DISCARDABLE_SIZE=45
+CONFIG_BT_BUF_ACL_RX_COUNT=2
+CONFIG_BT_BUF_EVT_RX_COUNT=2
+
+CONFIG_BT_L2CAP_TX_BUF_COUNT=2
+CONFIG_BT_CTLR_RX_BUFFERS=1
+CONFIG_BT_BUF_ACL_TX_COUNT=3
+CONFIG_BT_BUF_ACL_TX_SIZE=27

samples/bluetooth/central_hr/sample.yaml

@@ -5,6 +5,14 @@ tests:
     arch_allow: x86
     harness: bluetooth
     tags: bluetooth
+  sample.bluetooth.central_hr.minimal:
+    harness: bluetooth
+    platform_allow:
+      - bbc_microbit
+    integration_platforms:
+      - bbc_microbit
+    extra_args: EXTRA_CONF_FILE=prj_minimal.conf
+    tags: bluetooth
   sample.bluetooth.central_hr.bt_ll_sw_split.extended:
     harness: bluetooth
     platform_allow:

samples/bluetooth/peripheral_hr/prj_minimal.conf

@@ -103,7 +103,6 @@ CONFIG_BT_BUF_EVT_DISCARDABLE_SIZE=45
 CONFIG_BT_BUF_ACL_RX_COUNT=2
 CONFIG_BT_BUF_EVT_RX_COUNT=2
 
-CONFIG_BT_CONN_TX_MAX=2
 CONFIG_BT_L2CAP_TX_BUF_COUNT=2
 CONFIG_BT_CTLR_RX_BUFFERS=1
 CONFIG_BT_BUF_ACL_TX_COUNT=3

samples/bluetooth/peripheral_hr/sample.yaml

@@ -10,6 +10,14 @@ tests:
     integration_platforms:
       - qemu_cortex_m3
     tags: bluetooth
+  sample.bluetooth.peripheral_hr.minimal:
+    harness: bluetooth
+    platform_allow:
+      - bbc_microbit
+    integration_platforms:
+      - bbc_microbit
+    extra_args: EXTRA_CONF_FILE=prj_minimal.conf
+    tags: bluetooth
   sample.bluetooth.peripheral_hr.bt_ll_sw_split.extended:
     harness: bluetooth
     platform_allow: