RandomKey

Pictures:http://anykey0x.de/

Status

Started: September 21 2013
Status: Active
Goal: experiment with Eagle and making pcb's and ending with an awesome thingy.
Who: Ardillo

Description

Thanks to the guys of puscii. I found out that there is/was an event at Ordina Nieuwegein and thanks of that I found the open source project of Tim Becker.

AnyKey0x.de

Tim designed the AnyKey0x.de which is a small development board. As an enthousiast of small-and-capable-of-a-lot hardware I really wanted one, and with me a couple others. Since Tim made his project completely open source, I would like to thank Tim for sharing such an awesome project. All the kudo's (or base) belong to you.

RandomKey

The only change I made for now is just the text on the board, but it would be nice if we made some major changes to it. That depends a little on the enthusiasm we get from it. So at the moment it's just a fork of the original with no enhancements what so ever.

Building

Skills

Before doing this I needed to refresh my skills with Eagle. I used a simple howto guide on the sparfun website.
SMD-Soldering
Eagle: Schematics
Eagle: PCB Layout
In the end you'll have a fully (Sparkfun modified) Eagle setup and the knowledge to make a Serial to USB converter, because it's the training object of the tutorial.

PCB

Get the board printed by a company like smart-prototyping.com and search for the needed hardware. It is actually better to look for the parts first, but we'll see. Zarya from hackerspace Bitlair pointed me to some PCB fabhouses. I pasted their URL's in the reference. For this prototype I'm going to use smart-prototyping.com, but they need 10 gerber files instead of the normal 7. Which can be found on their website.

All Files: no offset, no mirror,no rotate, no upside down

Use EXCELLON
.TXT (Drill & Holes)

Use Gerber_RS274X:
.GML (Outline)
.GTP (Solder Paste Top)
.GBP (Solder Paste Bottom)
.GTS (Solder Mask Top)
.GBS (Solder Mask Bottom)
.GTO (Silk Screen Top)
.GBO (Silk Screen Bottom)
.GTL (Top layer)
.GBL (Bottom Layer)

Because the normal CAM processor only generates 7 of 10 Gerber files, I made a special .cam file which can be downloaded here. This will generate the asked 10 Gerber files. No guarantee, I'll let you know when the boards arrive.

Check Gerber Files

You can check the files with a free viewer downloadable here. This tool is Windows only :( I ran it in an Win7 VM, works fine.

Costs of parts

Some parts are bought at the farnell webshop others at RSonline. This was done because farnell sells resistors and capacitors only by big amounts. We don't need 500 resistors for this project. Buying parts in small amounts is more expensive for each part but in the end it was almost €50 cheaper than buying the parts in big amounts. So maybe for the future, when we decide to make 500 handmade RandomKeys, this will be a solution ;) NOTE: for every part I ordered a bit more then the amount of PCB's we have, so we have some spare parts if some noob lets the magic smoke escape.

part	url	amount	total price
Printing PCB (10x package) + shipping	Smart Prototyping	10	€18.18 incl. taxes + shipping
(Farnell) C&K components KMR241G - pushbutton	C&K components KMR241G - pushbutton	25	€13,50
(Farnell) Abracon - ABM8G - 25MHz Crystal	Abracon - ABM8G - 25MHz Crystal	12	€13,32
(Farnell) FCI micro USB B, receptacle, SMT, RA, 5WAY	FCI micro USB B, receptacle, SMT, RA, 5WAY	12	€6,00
(RSonline) MCU 32-Bit ARM Cortex M3 - LPC1343FBD48	MCU 32-Bit ARM Cortex M3 - LPC1343FBD48	12	€39,60
(RSonline) OSRAM LED 0603 blue	OSRAM LED 0603 blue	20	€2,76
(RSonline) Schottky Diode 3-Pin SOT-23 - BAT54C	Schottky Diode 3-Pin SOT-23 - BAT54C	20	€2,80
(RSonline) MOSFET 3-Pin SOT-23 - BSS84	MOSFET 3-Pin SOT-23 - BSS84	20	€3,30
(RSonline) MCP1801T 5-Pin SOT-23	MCP1801T 5-Pin SOT-23	20	€6,60
(RSonline) Capacitor 0603 100nF	Capacitor 0603 100nF	50	€3,75
(RSonline) Capacitor 0603 1uF	Capacitor 0603 1uF	50	€3,50
(RSonline) Capacitor 0603 18pF	Capacitor 0603 18pF	50	€1,45
(RSonline) Resistor 0603 33 Ohm	Resistor 0603 33 Ohm	50	€1,05
(RSonline) Resistor 0603 100 Ohm	Resistor 0603 100 Ohm	50	€1,40
(RSonline) Resistor 0603 1.5k Ohm	Resistor 0603 1.5k Ohm	50	€1,05
(RSonline) Resistor 0603 10k Ohm	Resistor 0603 10k Ohm	50	€1,05
		crazy Dutch taxes (21%)	€21,24
		Total incl. spares	€140,55

Costs of one RandomKey

Like I said above we calculated some spare parts incase you fry them, but it's a little odd to pay for spare parts when you don't use them. So if somebody wants a kit, what would be the cost of that. Without soldering mistakes that is.

part	amount	each	total
RandomKey PCB	1	€1,82	€1,82 incl. taxes
C&K components KMR241G - pushbutton	2	€0,54	€1,08
Abracon - ABM8G - 25MHz Crystal	1	€1,11	€1,11
FCI micro USB B, receptacle, SMT, RA, 5WAY	1	€0,50	€0,50
MCU 32-Bit ARM Cortex M3 - LPC1343FBD48	1	€3,30	€3,30
OSRAM LED 0603 blue	1	€0,138	€0,138
Schottky Diode 3-Pin SOT-23 - BAT54C	1	€0,14	€0,14
MOSFET 3-Pin SOT-23 - BSS84	1	€0,165	€0,165
MCP1801T 5-Pin SOT-23	1	€0,33	€0,33
Capacitor 0603 100nF	2	€0,075	€0,15
Capacitor 0603 1uF	2	€0,07	€0,14
Capacitor 0603 18pF	2	€0,029	€0,058
Resistor 0603 33 Ohm	2	€0,021	€0,042
Resistor 0603 100 Ohm	1	€0,028	€0,028
Resistor 0603 1.5k Ohm	2	€0,021	€0,042
Resistor 0603 10k Ohm	3	€0,021	€0,063
		again taxes (21%)	€1,53
		total	€10,64

Reference

AnyKey0x.de -- the one and only original
AnyKey0x.de Github -- all the files including sdk
Post @knutsel.org -- making cheap PCB's
MakePCB.com -- for making PCB's off course
iTead -- if <10, cheap one
Smart Prototyping -- cheapest one by far

Software

EAGLE PCB Software -- Eagle PCB designer
viewplot -- Free viewer of gerber files (last check before sending it to fabhouse)

Pictures