nightingale

nightingale is the production microcontroller board for the coquette keyboard. note that this project, this board, the associated keyboard shields, and all firmware, is untested and provided with no guarantees or liability for failures, safety hazards, reguatory compliance, and/or injuries and/or losses in any form.

the LICENSE only applies to original work here. some design files, 3D models, footprints, etc are from other sources like manufacturers and libraries and their license applies

bill of materials

qty	part	description
1	Raytac MTBT53-1M nRF5340 module	this is the microcontroller that runs the keyboard
1	TI TPS62842DGRR DCDC converter	chosen for its 60nA quiescent current, this powers it
1	TI BQ25186 lipoly charger	charges the battery
1	Sharp memory-in-pixel LCD	Pick one that fits on top and has the 10-pin connection that matches the pinout, a few sizes should work
1	TI TPS22917DBV	high side load switch for addressable RGB power. the quiescent on those things is soooooo high relative to the keeb you'll probably want to turn off power completely on battery
1	32.768KHz 9pF 3215 2-pin SMD crystal	external LFXO to reduce power use compared to internal oscillator
1	TI TSD05C TVS diode	protects USB VBUS input from ESD events
4	TI TPD4E1U06 TVS diode arrays	protects exposed data pins + USB data lines from ESD events
1	390pF NP0 ceramic capacitor	used to set ARGB power switch slew rate
1	560pF NP0 ceramic capacitor	the sharp memory display wants it, idk why
5	10nF 0603 ceramic capacitors	two for USB power RC filter, one for battery voltage sampling, two for button debounce
8	0.1uF 0603 ceramic capacitors	used for decoupling
9	1uF 0603 ceramic capacitors	used for decoupling
2	1uF 0805 tantanlum polymer capacitors	decoupling, ceramic may be okay but I wanted to reduce ringing risk
3	4.7uF 0805 ceramic capacitors	used for decoupling
2	10uF 0805 ceramic capacitors	decoupling, but more power!
1	R2.2 0805 thick film resistor	VBUS input surge protection
1	0805 1% resistor for DCDC vset	0R - 1.8V, 1.74k - 2.2V, 21.5k - 3V, 28.7k - 3.1V, 38.3k - 3.2V, 52.3k - 3.3V – use 52.3k if you want accessories that use power to work, but 1.8-2.2V is probably the most efficient if no screen, no add-ons, no display, and no UV underglow on גחלילית או פרפר
2	R374 0805 thick film resistors	one for current limiting LED data output, one for current limiting status LED
2	5.1k 0805 resistors	identify USB-C device
1	7.5M 0805 1% or better resistor	one leg of battery level voltage divider
1	10M 0805 1% or better resistor	the other leg of battery level voltage divider
2	10k*4 4x0603 resistor arrays	a few uses, mostly pulling up or down pins
1	R33*4 4x0603 convex resistor array	terminating i2c and SWD
2	10uH 0603	nRF internal DCDC
1	2.2uH 1008/2520 inductor	DCDC inductor
1	1206 ferrite - 60-120 Ohm or so	USB power filtering
2	0805 ferrites - 240 Ohm or so	LCD analog power filtering
2	TSC4A	side mount tactile switches for power and reset buttons
1	SMD USB 2.0 USB-C connector	the most common top-mount USB-C connector there is. take your pick, seriously, they almost all will fit but the GCT USB4105 is the one the footprint's actually meant for
1	2-pin horizontal PicoBlade connector	battery input
1	28-pin 0.5mm pitch FFC SMD connector	output to keyboard, be sure the mounting legs will fit
1	10-pin 0.5mm pitch FPC SMD connector	output to LCD, be sure the mounting legs will fit
1	JST_SH_SM03B-SRSS-TB_1x03 or similar	ARGB output
1	JST_SH_SM04B-SRSS-TB_1x04 or similar	Adafruit Stemma QT-like i2c output
1	JST_SH_SM08B-SRSS-TB_1x08 or similar	Pimoroni SP/CE-like SPI and PWM output
6	Mill-Max 0295-0-15-15-06-27-10-0	for Hackaday v1.69bis shitty add ons
4	SK6805D-EC3227 ARGB LEDs	picked for the 0.25mA quiescent, still even at 0% brightness the 1mA total will drain a 240mAh battery in a day. be sure you use the load switch wisely
1	0805 LED	for a status light. have fun!