CHANGE LOG

2015-02-17 Joined with update page

2015-02-14 first version

INTRODUCTION

So I designed a circuit, without making a pcb and sending it to OSHPark today. First I want to make sure, if what I've done is correct or not and right now I'm too confused and tired to tell. And if so, I'm going to breadboard it and use some perfboard or design the pcb and try to etch it myself. I'm too spoiled. There is so much BS on the web, how you would have to connect an ULN2803 to LEDs and so on. Has anyone any complaints or hints for me? My plan is to loop through each column and set the shift registers. Latch off while switching the rows. This is supposed to be the prototype controller for the displays I made in:

• 0x01 notes for the future - can anyone have too many displays? - Introduction of pcbs
• 0x02 notes for the future [UPDATE] - soldering with a toaster oven

SCHEMATICS

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UPDATE

BC548 is not a PNP, even if I write BC548 next to a PNP :D Fail. So I switched it with an BC516 - PNP darlington transistor - had to buy it, though :( I think there is an eagle library fail, where pins 12 and 10 are swapped, but the shiftout function of the arduino libraries is software based, so I can swap that back. I hope this will etch well, some jumper wires and heavy drilling should make this a nice little arduino / 74hc595 / uln2803 / BC516 demo board. The switch is supposed to trigger the interrupt later - plan here is to put the arduino in sleep mode, trigger it on when pressed, so you can read the time and it goes off after 3-5 seconds. I think I will use the 3D files of #Stargate Atlantis Scanner Remote for the case, once it's done.

THOUGHTS

- I re-evaluated the power consumption of this board, I never thought of resistors. Kind of weird, seems like I'm missing some basics I could have learned already, but I never had an education in electronics, so... yeah. I should start a "revisiting" basics video log or something.

- http://www.ti.com/lit/ds/symlink/tlc5916.pdf - I should check the prices of those and against 74hc595+ULN2803A+8LEDs instead. First look on eBay gave 2,65eur each for buying 10. http://www.ebay.de/itm/10-pcs-TLC5916IN-TEXAS-LED-Treiber-Linear-DIP16-NEW-/331457350079?pt=Bauteile&hash=item4d2c65c9bf

- SHIT. That did not happen! I didn't check for the spacing of the displays, I designed the whole board on the assumption, that the displays would be 0.2" longer. Gaaaah. Phew, that deescalated quickly.