Add ZannenDongle_UF2

.github/workflows/workflow.yml

@@ -2,9 +2,12 @@ on:
   pull_request:
     branches:
       - main
+      - dev
   push:
     branches:
       - main
+      - dev
+  create:
   workflow_dispatch:
 
 concurrency:
@@ -189,15 +192,16 @@ jobs:
       fail-fast: false
       matrix:
         boards: [
-                  {boardname: "nrf52840dongle/nrf52840", fileformat: "hex", filename: "SlimeNRF_Nordic_eByte_Dongle_Receiver"}, 
-                  {boardname: "holyiot_21017/nrf52840", fileformat: "hex", filename: "SlimeNRF_Holyiot_Dongle_Receiver"}, 
-                  {boardname: "promicro_uf2/nrf52840", fileformat: "uf2", filename: "SlimeNRF_ProMicro_Receiver"}, 
-                  {boardname: "xiao_ble/nrf52840", fileformat: "uf2", filename: "SlimeNRF_XIAO_Receiver"}, 
-                  {boardname: "etee_dongle_uf2/nrf52840", fileformat: "uf2", filename: "SlimeNRF_etee_Receiver"}, 
-                  {boardname: "nrf52840dk/nrf52840", fileformat: "hex", filename: "SlimeNRF_nRF52840dk_Receiver"}, 
-                  {boardname: "butterfly_p1_uf2/nrf52833", fileformat: "uf2", filename: "SlimeNRF_Butterfly_P1_Receiver"}, 
-                  {boardname: "butterfly_p2_uf2/nrf52833", fileformat: "uf2", filename: "SlimeNRF_Butterfly_P2_Receiver"}, 
-                  {boardname: "butterfly_p3/nrf52820", fileformat: "hex", filename: "SlimeNRF_Butterfly_P3_Receiver"},
+                  #{boardname: "nrf52840dongle/nrf52840", fileformat: "hex", filename: "SlimeNRF_Nordic_eByte_Dongle_Receiver"}, 
+                  #{boardname: "holyiot_21017/nrf52840", fileformat: "hex", filename: "SlimeNRF_Holyiot_Dongle_Receiver"}, 
+                  #{boardname: "promicro_uf2/nrf52840", fileformat: "uf2", filename: "SlimeNRF_ProMicro_Receiver"}, 
+                  #{boardname: "xiao_ble/nrf52840", fileformat: "uf2", filename: "SlimeNRF_XIAO_Receiver"}, 
+                  #{boardname: "etee_dongle_uf2/nrf52840", fileformat: "uf2", filename: "SlimeNRF_etee_Receiver"}, 
+                  #{boardname: "nrf52840dk/nrf52840", fileformat: "hex", filename: "SlimeNRF_nRF52840dk_Receiver"}, 
+                  #{boardname: "butterfly_p1_uf2/nrf52833", fileformat: "uf2", filename: "SlimeNRF_Butterfly_P1_Receiver"}, 
+                  #{boardname: "butterfly_p2_uf2/nrf52833", fileformat: "uf2", filename: "SlimeNRF_Butterfly_P2_Receiver"}, 
+                  #{boardname: "butterfly_p3/nrf52820", fileformat: "hex", filename: "SlimeNRF_Butterfly_P3_Receiver"},
+                  {boardname: "zannendongle_uf2/nrf52840", fileformat: "uf2", filename: "SlimeNRF_ZannenDongle_Receiver"},
                 ]
     runs-on: ubuntu-latest
     steps:

boards/zannen/zannendongle_uf2/CMakeLists.txt

@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+zephyr_library_sources(board.c)

boards/zannen/zannendongle_uf2/Kconfig.zannendongle_uf2

@@ -0,0 +1,5 @@
+# Copyright (c) 2025 SlimeVR Contributors
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_ZANNENDONGLE_UF2
+	select SOC_NRF52840_QIAA

boards/zannen/zannendongle_uf2/board.c

@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2025 SlimeVR Contributors.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Board initialization for ZannenDongle with RFX2401C FEM.
+ *
+ * The nRF52840's internal REG0 (LDO/DCDC stage for 1.8V radio supply)
+ * must be configured correctly for the RFX2401C FEM to operate.
+ * We set REG0 to 3.0V (VOUT_3V0) on first boot to ensure proper
+ * FEM supply voltage. This is written to UICR so it persists.
+ */
+
+#include <zephyr/init.h>
+#include <hal/nrf_power.h>
+
+static int board_zannendongle_uf2_init(void)
+{
+
+	/*
+	 * The RFX2401C FEM is typically powered from the nRF52840's
+	 * VDD_nRF (REG0 output) or an external LDO at 3.0V-3.3V.
+	 *
+	 * If the main regulator is in HIGH mode and REGOUT0 is still
+	 * at its POR default (1.8V), we reprogram it to 3.0V and
+	 * trigger a system reset so the change takes effect.
+	 *
+	 * This is a one-time initialization; after the reset,
+	 * REGOUT0 will already be at 3.0V and this code becomes a no-op.
+	 */
+	if ((nrf_power_mainregstatus_get(NRF_POWER) ==
+	     NRF_POWER_MAINREGSTATUS_HIGH) &&
+	    ((NRF_UICR->REGOUT0 & UICR_REGOUT0_VOUT_Msk) ==
+	     (UICR_REGOUT0_VOUT_DEFAULT << UICR_REGOUT0_VOUT_Pos))) {
+
+		NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen << NVMC_CONFIG_WEN_Pos;
+		while (NRF_NVMC->READY == NVMC_READY_READY_Busy) {
+			;
+		}
+
+		NRF_UICR->REGOUT0 =
+		    (NRF_UICR->REGOUT0 & ~((uint32_t)UICR_REGOUT0_VOUT_Msk)) |
+		    (UICR_REGOUT0_VOUT_3V0 << UICR_REGOUT0_VOUT_Pos);
+
+		NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren << NVMC_CONFIG_WEN_Pos;
+		while (NRF_NVMC->READY == NVMC_READY_READY_Busy) {
+			;
+		}
+
+		/* A reset is required for the REGOUT0 change to take effect */
+		NVIC_SystemReset();
+	}
+
+	return 0;
+}
+
+SYS_INIT(board_zannendongle_uf2_init, PRE_KERNEL_1,
+	 CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);

boards/zannen/zannendongle_uf2/board.cmake

@@ -0,0 +1,9 @@
+# Copyright (c) 2025 SlimeVR Contributors
+# SPDX-License-Identifier: Apache-2.0
+
+board_runner_args(jlink "--device=nrf52840_xxaa" "--speed=4000")
+board_runner_args(pyocd "--target=nrf52840" "--frequency=4000000")
+
+include(${ZEPHYR_BASE}/boards/common/nrfjprog.board.cmake)
+include(${ZEPHYR_BASE}/boards/common/jlink.board.cmake)
+include(${ZEPHYR_BASE}/boards/common/pyocd.board.cmake)

boards/zannen/zannendongle_uf2/board.yml

@@ -0,0 +1,8 @@
+# Copyright (c) 2025 SlimeVR Contributors
+# SPDX-License-Identifier: Apache-2.0
+
+board:
+  name: zannendongle_uf2
+  vendor: zannen
+  socs:
+    - name: nrf52840

boards/zannen/zannendongle_uf2/zannendongle_uf2.dts

@@ -0,0 +1,126 @@
+// Copyright (c) 2025 SlimeVR Contributors
+// SPDX-License-Identifier: Apache-2.0
+
+/dts-v1/;
+#include <nordic/nrf52840_qiaa.dtsi>
+
+// PWM pin assignment for RGB status LED
+// Red:   P0.12, Green: P0.08, Blue:  P1.09
+&pinctrl {
+	pwm0_default: pwm0_default {
+		group1 {
+			psels = <NRF_PSEL(PWM_OUT0, 0, 12)>,
+				<NRF_PSEL(PWM_OUT1, 0, 8)>,
+				<NRF_PSEL(PWM_OUT2, 1, 9)>;
+			nordic,drive-mode = <NRF_DRIVE_D0S1>;
+			nordic,invert;
+		};
+	};
+
+	pwm0_sleep: pwm0_sleep {
+		group1 {
+			psels = <NRF_PSEL(PWM_OUT0, 0, 12)>,
+				<NRF_PSEL(PWM_OUT1, 0, 8)>,
+				<NRF_PSEL(PWM_OUT2, 1, 9)>;
+			low-power-enable;
+		};
+	};
+};
+
+/ {
+	model = "ZannenDongle_uf2";
+	compatible = "zannendongle_uf2";
+
+	chosen {
+		zephyr,sram = &sram0;
+		zephyr,flash = &flash0;
+		zephyr,console = &cdc_acm_uart0;
+		zephyr,shell-uart = &cdc_acm_uart0;
+	};
+
+	// RFX2401C FEM: simple 2-control-pin front-end module
+	// Uses nRF21540 GPIO-only driver via MPSL for TX/RX switching.
+	// The nRF21540 driver is MPSL-native and correctly handles ESB
+	// radio events to toggle TXEN/RXEN automatically.
+	// TXEN = P1.00, RXEN = P0.24
+	nrf_radio_fem: rfx2401c_fem {
+		compatible = "nordic,nrf21540-fem";
+		tx-en-gpios = <&gpio1 0 GPIO_ACTIVE_HIGH>;    // RFX2401C TXEN (P1.00)
+		rx-en-gpios = <&gpio0 24 GPIO_ACTIVE_HIGH>;   // RFX2401C RXEN (P0.24)
+	};
+
+	// PWM-driven RGB LED
+	pwmleds {
+		compatible = "pwm-leds";
+		pwm_led0: pwm_led_0 {
+			pwms = <&pwm0 0 PWM_MSEC(1) PWM_POLARITY_INVERTED>;
+		};
+		pwm_led1: pwm_led_1 {
+			pwms = <&pwm0 1 PWM_MSEC(1) PWM_POLARITY_INVERTED>;
+		};
+		pwm_led2: pwm_led_2 {
+			pwms = <&pwm0 2 PWM_MSEC(1) PWM_POLARITY_INVERTED>;
+		};
+	};
+
+	aliases {
+		pwm-led0 = &pwm_led0;
+		pwm-led1 = &pwm_led1;
+		pwm-led2 = &pwm_led2;
+	};
+
+	// Simple GPIO LED (fallback indicator on Red channel)
+	zephyr,user {
+		led-gpios = <&gpio0 12 (GPIO_ACTIVE_LOW | GPIO_OPEN_DRAIN)>;
+	};
+};
+
+// nRF52840 internal main regulator (REG1) — use LDO mode by default.
+// DCDC mode requires external LC components; use LDO for guaranteed stability.
+// If the PCB includes the DCDC inductor/capacitor, change to NRF5X_REG_MODE_DCDC.
+&reg1 {
+	regulator-initial-mode = <NRF5X_REG_MODE_LDO>;
+};
+
+&gpio0 {
+	status = "okay";
+};
+
+&gpio1 {
+	status = "okay";
+};
+
+&gpiote {
+	status = "okay";
+};
+
+&pwm0 {
+	status = "okay";
+	pinctrl-0 = <&pwm0_default>;
+	pinctrl-1 = <&pwm0_sleep>;
+	pinctrl-names = "default", "sleep";
+};
+
+// USB peripheral with CDC ACM UART console
+zephyr_udc0: &usbd {
+	compatible = "nordic,nrf-usbd";
+	status = "okay";
+	cdc_acm_uart0: cdc_acm_uart0 {
+		compatible = "zephyr,cdc-acm-uart";
+	};
+};
+
+// CryptoCell not needed for receiver firmware
+&cryptocell {
+	status = "disabled";
+};
+
+// NFC not used, disable to free GPIO pins
+&nfct {
+	status = "disabled";
+};
+
+// Link the FEM to the radio peripheral
+&radio {
+	fem = <&nrf_radio_fem>;
+};

boards/zannen/zannendongle_uf2/zannendongle_uf2.yaml

@@ -0,0 +1,14 @@
+# Copyright (c) 2025 SlimeVR Contributors
+# SPDX-License-Identifier: Apache-2.0
+
+identifier: zannendongle_uf2
+name: ZannenDongle_uf2
+vendor: zannen
+type: mcu
+arch: arm
+ram: 256
+flash: 1024
+toolchain:
+  - zephyr
+  - gnuarmemb
+  - xtools

boards/zannen/zannendongle_uf2/zannendongle_uf2_defconfig

@@ -0,0 +1,15 @@
+# Copyright (c) 2025 SlimeVR Contributors
+# SPDX-License-Identifier: Apache-2.0
+
+CONFIG_ARM_MPU=y
+CONFIG_HW_STACK_PROTECTION=y
+
+CONFIG_USB_DEVICE_MANUFACTURER="Zannen"
+CONFIG_USB_DEVICE_PRODUCT="SlimeNRF Receiver ZannenDongle"
+
+# RGB LED color mode
+CONFIG_LED_RGB_COLOR=y
+
+# Generate UF2 file for Adafruit UF2 bootloader flashing
+CONFIG_BUILD_OUTPUT_UF2=y
+CONFIG_FLASH_LOAD_OFFSET=0x1000

boards/zannendongle_uf2.conf

@@ -0,0 +1,7 @@
+# ZannenDongle_uf2 board-specific Kconfig fragment (applied on top of defconfig)
+
+CONFIG_USB_DEVICE_MANUFACTURER="Zannen"
+CONFIG_USB_DEVICE_PRODUCT="SlimeNRF Receiver ZannenDongle"
+
+# RGB LED color mode
+CONFIG_LED_RGB_COLOR=y

pm_static_zannendongle_uf2_nrf52840.yml

@@ -0,0 +1,12 @@
+# Partition Manager static configuration for ZannenDongle_uf2 (nRF52840)
+# Uses Adafruit UF2 bootloader at 0x1000 offset
+bootloader:
+  address: 0x0
+  end_address: 0x1000
+  region: flash_primary
+  size: 0x1000
+uf2_bootloader:
+  address: 0xf4000
+  end_address: 0x100000
+  region: flash_primary
+  size: 0xc000

sample.yaml

@@ -5,4 +5,5 @@ tests:
       - nrf52840dk/nrf52840
       - nrf52840dongle/nrf52840
       - xiao_ble/nrf52840
+      - zannendongle_uf2/nrf52840
     sysbuild: true

src/connection/esb.c

@@ -314,11 +314,9 @@ static void esb_deinitialize(void)
 		esb_initialized = false;
 		LOG_INF("Deinitializing ESB");
 		k_msleep(10); // wait for pending transmissions
-		if (esb_initialized)
-		{
-			LOG_INF("ESB denitialize cancelled");
-			return;
-		}
+		// Always call esb_disable() — do NOT re-check esb_initialized.
+		// The re-check races with esb_pair()'s hot loop which
+		// calls esb_initialize() during the 10ms sleep window.
 		esb_disable();
 	}
 	esb_initialized = false;
@@ -492,7 +490,9 @@ void esb_pair(void)
 
 void esb_reset_pair(void)
 {
-	esb_deinitialize(); // make sure esb is off
+	esb_pairing = false;      // Signal current pairing loop to exit
+	k_msleep(20);             // Wait for loop exit + its internal esb_deinitialize()
+	esb_deinitialize();       // Now safe: no concurrent ESB operations
 	esb_paired = false;
 }
 

src/console.c

@@ -168,21 +168,22 @@ static inline void strtolower(char *str) {
 
 static void print_help(void)
 {
-	printk("\nhelp                         Display this help text\n");
-
-	printk("\ninfo                         Get device information\n");
-	printk("uptime                       Get device uptime\n");
-	printk("list                         Get paired devices\n");
-	printk("reboot                       Soft reset the device\n");
-	printk("\nadd <address>                Manually add a device\n");
-	printk("remove                       Remove last device\n");
-	printk("pair                         Enter pairing mode\n");
-	printk("exit                         Exit pairing mode\n");
-	printk("clear                        Clear stored devices\n");
+	printk(
+		"\nhelp                         Display this help text\n"
+		"\ninfo                         Get device information\n"
+		"uptime                       Get device uptime\n"
+		"list                         Get paired devices\n"
+		"reboot                       Soft reset the device\n"
+		"\nadd <address>                Manually add a device\n"
+		"remove                       Remove last device\n"
+		"pair                         Enter pairing mode\n"
+		"exit                         Exit pairing mode\n"
+		"clear                        Clear stored devices\n"
 #if DFU_EXISTS
-	printk("\ndfu                          Enter DFU bootloader\n");
+		"\ndfu                          Enter DFU bootloader\n"
 #endif
-	printk("\nmeow                         Meow!\n");
+		"\nmeow                         Meow!\n"
+	);
 }
 
 static void console_thread(void)