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Component Layout

With around two dozen total components its hard to go wrong.  The chorder can be built on perfboard, stripboard, wirewrap or your can etch a pcb board.  If you create a layout, please send it to us, your layout may be just what someone else needs to help them build their board!  Please be sure to clearly state how you want to be listed when we post it.  From Name and email address (obfuscated by the wiki) to total anonymity, we will do our best to accommodate your request. Component numbers should match the ones used on the hardware page.

Here is a layout for a Seven key chorder with no LEDs or ISP. This is what Greg uses. The layout is for perfboard and wire but could be adapted to other methods.

click or select to enlarge
For the largest version of the above graphic, select it to enlarge, then select it again.
Component names and numbers match those used on the hardware page.

The layout below uses two 28 pin DIP wirewrap sockets and no breadboard. The IC uses one of the sockets. The components are all soldered into the other socket. Then the sockets are connected using wirewrap. In practice all ground lines are brought togther and solderd to the ground line of the USB cable and all VCC lines are brought together and soldered to the VCC line of the USB cable. In like fashion, the lines for the keyswitches are brought out to and soldered to one side of each of the switches and a ground line is run to the other. While a graphic is provided for referance, the wireing chart below should be used when doing the wraping. Check off each connection on the chart as you go.

click or select to enlarge
Component names and numbers match those used on the hardware page.

First, insert and then solder the following components into a 28pin DIP as indicated.

28 pin dip for use as
component socket
pincomponentpin
1 X1 28
2 27
3 C1 26
4 C2 25
5 24
6 C5 23
7 R4 22
8 D2 21
9 R3 20
10 D1 19
11 R2 18
12 R1 17
13 C3 16
14 C4 15

Warning I have not yet wired up the wirewrap board, once I have (and as such confirmed that the wire chart below is correct) I will remove this warning -Greg

Next use a wirewrap tool to connect the following pins. Remember to take into account that you are turning the socket upside down when you wrap. Check your pin numbers carefully. I will post photos with lables once I make this version of the chorder.

key
CS-# component socket pin number, 28 pin dip holding the circut components
IC-# IC socket socket pin number, 28 pin dip holding the AVR atmega168 ic
SW-# Switch number, each switch has 2 pins. One pin is wired to the IC, the other to Ground
USB-# The four lines of the usb cable (see hardware)
VCC power from line one of the usb cable
GND Ground line from line 4 of the usb cable
wired components tested
[ ] CS-1 CS-4 [ ]
[ ] CS-5 CS-23 [ ]
[ ] CS-6 VCC [ ]
[ ] CS-8 GND [ ]
[ ] CS-10 GND [ ]
[ ] CS-11 GND [ ]
[ ] CS-12 VCC [ ]
[ ] CS-13 CS-14 [ ]
[ ] CS-14 VCC [ ]
[ ] CS-15 GND [ ]
[ ] CS-16 CS-15 [ ]
[ ] CS-18 CS-17 [ ]
[ ] CS-18 USB-2 [ ]
[ ] CS-19 CS-18 [ ]
[ ] CS-20 CS-19 [ ]
[ ] CS-21 USB-3 [ ]
[ ] CS-22 CS-21 [ ]
[ ] CS-23 GND [ ]
[ ] CS-25 GND [ ]
[ ] CS-26 GND [ ]
[ ] CS-28 CS-3 [ ]
[ ] IC-2 CS-9 [ ]
[ ] IC-4 CS-7 [ ]
[ ] IC-7 CS-6 [ ]
[ ] IC-8 CS-5 [ ]
[ ] IC-9 CS-1 [ ]
[ ] IC-10 CS-28 [ ]
[ ] IC-12 SW-7 [ ]
[ ] IC-14 SW-1 [ ]
[ ] IC-15 SW-2 [ ]
[ ] IC-16 SW-3 [ ]
[ ] IC-17 SW-4 [ ]
[ ] IC-18 SW-5 [ ]
[ ] IC-19 SW-6 [ ]
[ ] SW-1-7(GND) GND [ ]
[ ] USB-1 VCC [ ]
[ ] USB-4 GND [ ]