global open time

use kicad 8, 9 still has some problems have 2 leds: power & debugging debugging: run a blink program and make sure your mcu is still alive. how to use the pin with the led? just solder pin header before or after the led. 2 layers put pin through the board -> bam, 2 layers you can connect then the two pins on the backside with a cable. there is no shame in that btw. suggestion: use labels. makes your design a bit easier. use disconnected mark in kicad if pins are not connected use power flags if you get errors regarding power you need to tell kicad where power is coming into the board hit p on keyboard use electrical rules checker pull-up & pull-down: check adrians doc if you do not connect the open switch directly to pin, there will be noise due to internal processes in the chip add pulldown resistor with low resastance so that noise rather goes to ground. how big pulldown resistors to be? (ricardo marques) for buttons you can use lke 5k, LEDs between 500 and 1k i2c depends on a few variables but between 900 and 5k. for 3.3v logic don't go over 2.5k getting started with electronics pgase 6 to 41. for this weeks assignment make beautiful pcb, not a square. it is the design week check ccc talk make power lines of fatter thickness on a pcb you see it better signal lines you want to be thin thick power lines can handle more current some more about pullup/pulldown by ricardo marques if you dont use pulldown pullup, there a tristate. its not defined what voltage is on the pin. internals of mC. this is explained further by neil in input devices only use bat gnd and bat vin if usb is not used. otherwise they will conflict. (source: rico)