HW1 - Microcontroller Kit

Overview

You will solder headers onto an mbed microcontroller kit, mount it to a laser-cut breadboard holder, create a developer account and verify that everything works by uploading a simple program to the microcontroller.

Instructions

• Once you are officially enrolled in the class, you will receive a mbed KL25Z microcontroller kit from us - it consists of a pre-populated printed circuit board, some headers, a breadboard, mounting hardware, and a mini USB cable. You will receive your kit at the beginning of the Soldering Lab. If you're not taking the soldering lab, you can pick up the kit in class.
• Attend the Soldering Lab this week to pick up the necessary skills and get started on this task (the lab is optional).
• Assemble and solder the kit following the step-by-step instructions below.
• Sign up for an mbed user account and learn how to program your board over USB. Become familiar with mbed terminology by looking at some of the provided example code and reading mbed in a Nutshell.
• Modify the the hello world example that blinks the on-board RBG LED so it alternates between red and green LEDs such that the LED is green for 400ms, then red for 100ms, then repeat, to convince yourself that your board works. Show your mounted board with running code to the GSI to get credit.

Step By Step Assembly Instructions

First solder the headers one by one. It's a good idea to first tack a single corner pin to check the alignment of the header before soldering all the other pins.

(Mbed-headers-presolder.jpg Download Mbed-headers-presolder.jpg, Mbed-headers-3-4s.jpg Download Mbed-headers-3-4s.jpg )

• Laser cut the breadboard carrier from Econowood. Start with a test cut on paper. (we have wood set aside for you - ask the lab managers).
• Illustrator source file: kl25z-breadboard-plate-single-layer-2015.ai Download kl25z-breadboard-plate-single-layer-2015.ai 
• Note: This file is set up for the large laser cutter; you may also have to move the position of the design if you are working with a partially used sheet of material. Again, the lab managers can help.
• Modify the file by adding your name in a place that will not be obscured by the microcontroller or breadboard.
• Optional: Instead of the design above, we also have a two-layer board design that's a bit more involved as you have to glue two layers on top of each other - kl25z-breadboard-plate-two-layer-2015.ai Download kl25z-breadboard-plate-two-layer-2015.ai . It's up to you which one you'd like to cut.

• Place and adhere the breadboard on its slot on the carrier by peeling off the backing from the foam adhesive.

• Remove the four rubber feet from the bottom of the KL25Z board.

• Place the KL25Z board on top of the laser cut carrier and fasten it with 4 nylon screws and nuts (nuts on top, screws on bottom as the screws are a bit too long)
  
  Mbed-nylon-hardware.jpg Download Mbed-nylon-hardware.jpg

• Add rubber feet (either the ones you took off, or new ones) to the bottom of the carrier board.
  
  Mbed-carrier-backside.jpg Download Mbed-carrier-backside.jpg

What to Submit

This is a short assignment. You should be able to finish the soldering part during your soldering lab; but you'll have to do the laser cutting separately (after completing safety training). If you are done by Wednesday, bring your completed board to class and show the running blinking LED code to Mark, Chris, Joanne, or Bjoern. Otherwise, bring your board in during lab hours this week and show the working board to a Mark, Chris, or Joanne, who can check you off.

Contents for one kit

1x mbed board: Freescale FRDM KL25Z from Mouser
Female 0.1" header:
1x Double row, 10 pos per row: Digikey PPPC102LFBN-RC
2x Double row, 8 pos: Digikey PPPC082LFBN-RC
1x Double row, 6 pos: Digikey PPPC062LFBN-RC
1x Mini USB Cable 3': Digikey Qualtek 3021003
1x Half-size breadboard: Digikey 377-2094-ND or Sparkfun
4x Nylon Screws 4-40 1/2" Keystone Electronics 9329 at Mouser
4x Nylon Hex Nuts Keystone Electronics 9605 at Mouser
5x Rubber feet 3M 0.3" bumpers at Digikey
Mounting Plate: Students self-cut mounting plate from Econowood

• Bulk items (distributed later):

• 1x Breadboarding wire bundle Adafruit 153
  10x Momentary Tactile Switch TE FSM6JH at Mouser
  Low Current LED 5mm through-hole:
  Red: Digikey Avago HLMP-4700 (buy 100)
  Green: Digikey Avago HLMP-4740 (buy 100)
  Yellow: Digikey Avago HLMP-4719 (buy 100)
  470 Ohm through-hole resistors for LEDs Yageo at Digikey (buy 300)