/* * EEG Testbed Firmware - Board Overlay * * Target: u-blox NINA-B3 (nRF52840) * * This overlay configures: * - USB CDC ACM for console * - SPI1 bus with 4 devices: FRAM, ADC, Accelerometer, Function Generator * - Custom GPIO outputs: Status LEDs, Lead-off switches, Reference control */ #include / { chosen { /* USB CDC ACM for console/shell */ zephyr,console = &cdc_acm_uart0; zephyr,shell-uart = &cdc_acm_uart0; zephyr,uart-mcumgr = &cdc_acm_uart0; }; aliases { /* Status LEDs */ lc-red = &lc_red; lc-green = &lc_green; lc-blue = &lc_blue; /* Lead-off switches */ sw-lod-vin = &sw_lod_vin; lo-1 = &lo_1; lo-2 = &lo_2; lo-3 = &lo_3; lo-4 = &lo_4; lo-5 = &lo_5; lo-6 = &lo_6; lo-7 = &lo_7; lo-8 = &lo_8; /* External reference control */ ref-switch = &ref_switch; ref-power = &ref_power; }; /* ======================================== * Status LEDs (Active Low) * ======================================== */ output_leds { compatible = "gpio-leds"; status = "okay"; lc_red: lc_red { gpios = <&gpio1 14 GPIO_ACTIVE_LOW>; label = "LC_RED"; }; lc_green: lc_green { gpios = <&gpio0 26 GPIO_ACTIVE_LOW>; label = "LC_GREEN"; }; lc_blue: lc_blue { gpios = <&gpio0 6 GPIO_ACTIVE_LOW>; label = "LC_BLUE"; }; }; /* ======================================== * Lead-Off Detection Switches (Active Low) * ======================================== */ output_leadoff_sw { compatible = "gpio-leds"; status = "okay"; sw_lod_vin: sw_lod_vin { gpios = <&gpio0 30 GPIO_ACTIVE_LOW>; }; lo_1: lo_1 { gpios = <&gpio0 14 GPIO_ACTIVE_LOW>; }; lo_2: lo_2 { gpios = <&gpio0 15 GPIO_ACTIVE_LOW>; }; lo_3: lo_3 { gpios = <&gpio0 16 GPIO_ACTIVE_LOW>; }; lo_4: lo_4 { gpios = <&gpio0 24 GPIO_ACTIVE_LOW>; }; lo_5: lo_5 { gpios = <&gpio0 25 GPIO_ACTIVE_LOW>; }; lo_6: lo_6 { gpios = <&gpio0 3 GPIO_ACTIVE_LOW>; }; lo_7: lo_7 { gpios = <&gpio0 28 GPIO_ACTIVE_LOW>; }; lo_8: lo_8 { gpios = <&gpio0 2 GPIO_ACTIVE_LOW>; }; }; /* ======================================== * External Reference Control (Active Low) * ======================================== */ output_external_reference { compatible = "gpio-leds"; status = "okay"; ref_switch: ref_switch { gpios = <&gpio0 4 GPIO_ACTIVE_LOW>; }; ref_power: ref_power { gpios = <&gpio0 5 GPIO_ACTIVE_LOW>; }; }; /* ADC channels for zephyr,user node */ zephyr,user { io-channels = <&ad4130 1>, <&ad4130 2>, <&ad4130 3>, <&ad4130 4>, <&ad4130 5>, <&ad4130 6>, <&ad4130 7>, <&ad4130 8>; }; }; /* ============================================================================ * Peripheral Configuration * ============================================================================ */ &uart0 { status = "okay"; }; &gpio0 { status = "okay"; }; &gpio1 { status = "okay"; }; /* ============================================================================ * SPI1 Bus Configuration * * Shared bus with 4 devices: * CS1 (P1.02): ADC (AD4130) - 5MHz * CS2 (P1.03): Accelerometer (BMA400) - 5MHz * CS3 (P0.17): Function Generator (AD9833) - 5MHz (uses FSYNC) * CS4 (P1.11): FRAM (CY15B108QN) - 5MHz * ============================================================================ */ &spi3 { compatible = "nordic,nrf-spim"; status = "okay"; pinctrl-0 = <&spi3_default>; pinctrl-1 = <&spi3_sleep>; pinctrl-names = "default", "sleep"; /* CS index: 0=AD4130, 1=BMA400, 2=AD9833, 3=FRAM */ cs-gpios = <&gpio1 2 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>, /* idx 0: AD4130 */ <&gpio1 3 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>, /* idx 1: BMA400 */ <&gpio0 17 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>, /* idx 2: AD9833 */ <&gpio1 11 (GPIO_ACTIVE_LOW)>; /* idx 3: FRAM */ /* ADC - Analog Devices AD4130-8 (24-bit Sigma-Delta) */ ad4130: ad4130@0 { compatible = "adi,ad4130-custom"; reg = <0>; /* CS index 0 */ spi-max-frequency = <5000000>; status = "okay"; #address-cells = <1>; #size-cells = <0>; #io-channel-cells = <1>; adc-mode = <0>; clock-type = <0>; /* 8 differential channels: AIN0-7 vs AIN8 (common reference) */ channel@1 { reg = <1>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = ; zephyr,resolution = <24>; zephyr,input-positive = ; zephyr,input-negative = ; }; channel@2 { reg = <2>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = ; zephyr,resolution = <24>; zephyr,input-positive = ; zephyr,input-negative = ; }; channel@3 { reg = <3>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = ; zephyr,resolution = <24>; zephyr,input-positive = ; zephyr,input-negative = ; }; channel@4 { reg = <4>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = ; zephyr,resolution = <24>; zephyr,input-positive = ; zephyr,input-negative = ; }; channel@5 { reg = <5>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = ; zephyr,resolution = <24>; zephyr,input-positive = ; zephyr,input-negative = ; }; channel@6 { reg = <6>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = ; zephyr,resolution = <24>; zephyr,input-positive = ; zephyr,input-negative = ; }; channel@7 { reg = <7>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = ; zephyr,resolution = <24>; zephyr,input-positive = ; zephyr,input-negative = ; }; channel@8 { reg = <8>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = ; zephyr,resolution = <24>; zephyr,input-positive = ; zephyr,input-negative = ; }; }; /* Accelerometer - Bosch BMA400 (3-axis) */ accelerometer: accelerometer@1 { compatible = "custom,bma400"; reg = <1>; /* CS index 1 */ spi-max-frequency = <5000000>; status = "okay"; }; /* Function Generator - Analog Devices AD9833 */ funcgen: funcgen@2 { compatible = "adi,ad9833"; reg = <2>; /* CS index 2 */ spi-max-frequency = <5000000>; fsync-gpios = <&gpio1 10 GPIO_ACTIVE_LOW>; status = "okay"; }; /* FRAM - Infineon CY15B108QN (1MB SPI F-RAM) */ fram: fram@3 { compatible = "infineon,cy15b108qn"; reg = <3>; /* CS index 3 */ spi-max-frequency = <2000000>; status = "okay"; }; }; /* ============================================================================ * USB CDC ACM (Virtual COM Port) * ============================================================================ */ &zephyr_udc0 { cdc_acm_uart0: cdc_acm_uart0 { compatible = "zephyr,cdc-acm-uart"; }; cdc_acm_uart1: cdc_acm_uart1 { compatible = "zephyr,cdc-acm-uart"; }; }; /* ============================================================================ * Pin Control (SPI1 Pins) * ============================================================================ */ &pinctrl { spi3_default: spi1_default { sck { psels = ; }; data { psels = , ; }; }; spi3_sleep: spi1_sleep { sck { psels = ; low-power-enable; }; data { psels = , ; low-power-enable; }; }; }; /* ============================================================================ * Disable Unused Board Defaults * ============================================================================ */ &led0 { status = "disabled"; }; &led1 { status = "disabled"; }; &led2 { status = "disabled"; }; &button0 { status = "disabled"; }; &button1 { status = "disabled"; }; &red_pwm_led { status = "disabled"; }; &blue_pwm_led { status = "disabled"; }; &green_pwm_led { status = "disabled"; }; &pwm0 { status = "disabled"; }; &i2c0 { status = "disabled"; }; &spi0 { status = "disabled"; }; &spi1 { status = "disabled"; }; &spi2 { status = "disabled"; };