anil08607/Smartwatch

hardware-contract.json

{
	"name": "Anil nRF52810 Smartwatch V1",
	"owner": "anil08607",
	"mcu": {
		"mpn": "NRF52810-QFAA-R",
		"flash_bytes": 196608,
		"ram_bytes": 24576,
		"supply_mode": "internal LDO; DCC unconnected; DCDCEN must remain zero",
		"pins": {
			"1": "NRF_DEC1",
			"2": "LF_X1",
			"3": "LF_X2",
			"4": "BAT_ADC",
			"5": "BUTTON1",
			"6": "BUTTON2",
			"7": "MOTOR_EN",
			"8": "CHG_INT",
			"9": "LCD_CS",
			"10": "LCD_SCK",
			"11": "LCD_MOSI",
			"12": "LCD_DC",
			"13": "V3V0",
			"14": "LCD_RESET",
			"15": "LCD_BL",
			"16": "I2C_SCL",
			"17": "I2C_SDA",
			"18": "BMA_INT1",
			"19": "BMA_INT2",
			"20": "RTC_INT",
			"21": "DEBUG_GPIO",
			"24": "NRST",
			"25": "SWCLK",
			"26": "SWDIO",
			"30": "RF_ANT",
			"31": "GND",
			"32": "NRF_DEC2",
			"33": "NRF_DEC3",
			"34": "HF_X1",
			"35": "HF_X2",
			"36": "V3V0",
			"45": "GND",
			"46": "NRF_DEC4",
			"48": "V3V0",
			"49": "GND"
		},
		"no_connect_pins": [22, 23, 27, 28, 29, 37, 38, 39, 40, 41, 42, 43, 44, 47]
	},
	"board": {
		"width_mm": 46,
		"height_mm": 46,
		"corner_radius_mm": 8,
		"thickness_mm": 1,
		"layers": 4,
		"copper_oz": 1,
		"minimum_trace_mm": 0.1,
		"minimum_clearance_mm": 0.1,
		"via_diameter_mm": 0.4,
		"via_drill_mm": 0.2,
		"copper_edge_clearance_mm": 0.2,
		"finish": "ENIG",
		"soldermask": "black",
		"silkscreen": "white",
		"stackup_status": "fabricator confirmation required"
	},
	"interfaces": {
		"J1": "USB-C 5 V charging only; USB data NC",
		"J2": {
			"1": "protected pack positive",
			"2": "GND"
		},
		"J3": {
			"1": "V3V0 reference",
			"2": "SWDIO",
			"3": "GND",
			"4": "SWCLK",
			"5": "NRST",
			"6": "P0.18 service GPIO"
		},
		"J4": "ER-TFT1.28-3 no-touch 15-way FPC",
		"J5": {
			"1": "pack thermistor TS",
			"2": "GND"
		},
		"M1": {
			"1": "V3V0 motor positive",
			"2": "MOSFET switched return"
		}
	},
	"electrical": {
		"main_rail_net": "V3V0",
		"main_rail_nominal_v": 3.05,
		"feedback_upper_ohm": 510000,
		"feedback_lower_ohm": 100000,
		"resistor_tolerance": 0.01,
		"reference_tolerance_assumed": 0.015,
		"input_pd_request_v": 5,
		"battery_cells": 1,
		"battery_charge_v": 4.2,
		"initial_charge_current_ma": 100,
		"battery_capacity_mah": 400,
		"battery_ntc": "SEMITEC 103AT-2, 10 kohm, B25/85 3435 K",
		"display_framebuffer_bytes": 115200
	},
	"rf": {
		"antenna": "RFANT3216120A5T",
		"matching_inductor_nh": 3.9,
		"matching_shunt_pf": 0.8,
		"antenna_series_start_nh": 6.8,
		"feed_width_mm": 0.34,
		"target_ohm": 50,
		"antenna_window": {
			"xmin": 2.3,
			"xmax": 9.3,
			"ymin": -23,
			"ymax": -17
		},
		"validation": "VNA tuning and final-enclosure radio tests required",
		"reference_corridor": {
			"xmin": 4.3,
			"xmax": 6.8,
			"ymin": -17,
			"ymax": -2
		}
	},
	"mechanical": {
		"case_width_mm": 54,
		"case_height_mm": 54,
		"case_thickness_mm": 18,
		"pcb_capture": "edge ledge with screwed top retainer; no PCB mounting holes",
		"strap_width_mm": 22,
		"water_resistance": "not rated",
		"controls": {
			"usb_side": "left (-X), centred at Y=0",
			"button_side": "right (+X)",
			"button_centres_mm": [[20.2, 3.5], [20.2, -3.5]],
			"button_cap_z_mm": 0.5,
			"usb_plug_body_envelope_mm": [20, 12, 6],
			"usb_plug_body_front_x_mm": -24.5
		}
	}
}