zephyr/boards: Add XIAO BLE NRF52840 SENSE board.

This commit adds Zephyr support for the XIAO BLE NRF52840 SENSE board from
Seeed Studio.

It also provides a good example of a richer Zephyr port than the default,
adding:
- Frozen modules (including asyncio, upysh, aioble and aiorepl).
- Enough MicroPython features to support using aioble (at least for the
  `temp_sensor.py` example).
- JSON, random, re, struct, etc.

Signed-off-by: Ned Konz <[email protected]>

Author: bikeNomad

ports/zephyr/boards/xiao_ble_nrf52840_sense.conf

@@ -0,0 +1,51 @@
+# Kconfig configuration for Seeed Studio's XIAO nRF52840 Sense
+
+CONFIG_NETWORKING=n
+CONFIG_CONSOLE_SUBSYS=n
+
+# for PDM microphone, set these three to y
+# and also enable in overlay
+CONFIG_AUDIO=n
+CONFIG_AUDIO_DMIC=n
+CONFIG_AUDIO_DMIC_NRFX_PDM=n
+
+# Enable Bluetooth
+CONFIG_BT=y
+CONFIG_BT_PERIPHERAL=y
+CONFIG_BT_CENTRAL=y
+CONFIG_BT_DEVICE_NAME="XIAO BLE nRF52840 Sense"
+CONFIG_BT_GATT_DYNAMIC_DB=y
+CONFIG_BT_DEVICE_NAME_DYNAMIC=y
+CONFIG_BT_GATT_CLIENT=y
+CONFIG_BT_L2CAP_TX_MTU=252
+CONFIG_BT_BUF_ACL_RX_SIZE=256
+CONFIG_BT_GATT_ENFORCE_SUBSCRIPTION=n
+
+CONFIG_MICROPY_HEAP_SIZE=98304
+CONFIG_MAIN_STACK_SIZE=8192
+
+# Enable drivers for peripherals
+CONFIG_GPIO=y
+CONFIG_I2C=y
+CONFIG_SPI=y
+CONFIG_PWM=y
+CONFIG_ADC=y
+
+CONFIG_FLASH=y
+CONFIG_FLASH_MAP=y
+CONFIG_FLASH_PAGE_LAYOUT=y
+
+CONFIG_DISK_ACCESS=n
+
+CONFIG_MICROPY_FROZEN_MODULES=y
+CONFIG_MICROPY_FROZEN_MANIFEST="boards/xiao_ble_nrf52840_sense/manifest.py"
+CONFIG_MICROPY_CONFIGFILE="boards/xiao_ble_nrf52840_sense/mpconfigport.h"
+
+# CONFIG_DYNAMIC_THREAD=y
+CONFIG_THREAD_CUSTOM_DATA=y
+CONFIG_THREAD_MONITOR=y
+CONFIG_THREAD_STACK_INFO=y
+
+CONFIG_LOG=n
+CONFIG_FP16=n
+CONFIG_BOOT_BANNER=n

ports/zephyr/boards/xiao_ble_nrf52840_sense.overlay

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2025 NED KONZ <[email protected]>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+// Replace default on-chip flash with external flash
+/delete-node/ &storage_partition;
+
+// 16Mib (2MiB) flash, mount as /flash
+&p25q16h {
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		storage_partition: partition@0 {
+			label = "storage";
+			reg = <0x00000000 0x200000>;
+		};
+	};
+};
+
+/ {
+	zephyr,user {
+		io-channels = <&adc 0>, <&adc 1>, <&adc 4>, <&adc 5>, <&adc 7>;
+	};
+};
+
+&adc {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	channel@0 {
+		reg = <0>;
+		zephyr,gain = "ADC_GAIN_1_6";
+		zephyr,reference = "ADC_REF_INTERNAL";
+		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
+		zephyr,input-positive = <NRF_SAADC_AIN0>; /* P0.02 */
+		zephyr,resolution = <12>;
+	};
+
+	channel@1 {
+		reg = <1>;
+		zephyr,gain = "ADC_GAIN_1_6";
+		zephyr,reference = "ADC_REF_INTERNAL";
+		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
+		zephyr,input-positive = <NRF_SAADC_AIN1>; /* P0.03 */
+		zephyr,resolution = <12>;
+	};
+
+	channel@4 {
+		reg = <4>;
+		zephyr,gain = "ADC_GAIN_1_6";
+		zephyr,reference = "ADC_REF_INTERNAL";
+		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
+		zephyr,input-positive = <NRF_SAADC_AIN4>; /* P0.28 */
+		zephyr,resolution = <12>;
+	};
+
+	channel@5 {
+		reg = <5>;
+		zephyr,gain = "ADC_GAIN_1_6";
+		zephyr,reference = "ADC_REF_INTERNAL";
+		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
+		zephyr,input-positive = <NRF_SAADC_AIN5>; /* P0.29 */
+		zephyr,resolution = <12>;
+	};
+
+	// AIN7: battery reading
+	channel@7 {
+		reg = <7>;
+		zephyr,gain = "ADC_GAIN_1_6";
+		zephyr,reference = "ADC_REF_INTERNAL";
+		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
+		zephyr,input-positive = <NRF_SAADC_AIN7>; /* P0.31 */
+		zephyr,resolution = <12>;
+	};
+};

ports/zephyr/boards/xiao_ble_nrf52840_sense/manifest.py

@@ -0,0 +1,7 @@
+include("$(MPY_DIR)/extmod/asyncio")
+
+freeze("$(PORT_DIR)/modules")
+
+require("upysh")
+require("aioble")
+require("aiorepl")

ports/zephyr/boards/xiao_ble_nrf52840_sense/mpconfigport.h

@@ -0,0 +1,27 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#define MICROPY_CONFIG_ROM_LEVEL (MICROPY_CONFIG_ROM_LEVEL_EXTRA_FEATURES)
+
+#include "../mpconfigport.h"