Step 5 - Map & Pick : 無料・フリー素材/写真
Step 5 - Map & Pick / Aleks J Clark
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
|---|---|
| 説明 | After all components that are going to be removed have been removed, you'll need to map the membrane switches to contact points.First, remove the membrane from the switchNext, using a voltmeter set to continuity mode, test for continuity between each side of the membrane switch's pad and one of the daughterboard solder points. At this point, you'll probably figure out that ALL of the inputs mapped to solder points for the daughter board, including the ribbon cables and the other wires you removed. I was tempted to try to connect everything via the daughterboard pads, but a problem arose: multiplexing!As I explored the main pcb, I found that the membrane switches shared inputs, so that K15 used pads 7 and 15, while K16 used pads 7 and 16, and K10 used pads 16 and 21. This in itself is not a problem, it is a common way to reduce the number of inputs in a given electronics layout. However, the keyboard PCB also uses multiplexing, so attempting to merge the two would require the use of diodes and a lot of thinking/diagramming/etc.To avoid this, I did picked membrane buttons that did not have wildly overlapping pad numbers, for example K17 (p21 & p15) and K16 (p18 & p15). This way, I can connect p15 to keyboard row 1, and p18 and p21 to keyboard columns 4 and 5. The important part is that keys that will be pressed simultaneously should all be on the same keyboard row (not necessarily the actual key row on the keyboard row, eg qwerty, but actually the row pad on the keyboard PCB). |
| 撮影日 | 2009-11-16 04:34:31 |
| 撮影者 | Aleks J Clark , Murfreesboro, TN |
| タグ | |
| 撮影地 | |
| カメラ | Canon PowerShot S5 IS , Canon |
| 露出 | 0.25 sec (1/4) |
| 開放F値 | f/2.7 |
| 焦点距離 | 6 mm |