wow your getting way ahead of me, i was going to look into the SPI library for the coding since i have no experience with this when i got to this stage. and hey at least you have the dignity to admit when your wrong and fix it. but moving the connections down one doesnt clutter up the circuit, so im happy. and Im just glad that you actually help, unlike 90% of this forum who just seem interested in being sarcastic snobs.
so how about a 2222 npn for the anodes with a 1k resistor? (I have lots of those on hand)I think i saw somewhere that they can handle an amp? isnt the max we figured out earlier to be 720 mA?
The hardware design really needs to tie in with the software in a case like this.
Look at 2n2222 specs again, I posted it earlier - need a lot of base current to turn them fully on. I don't think thats the right transistor for turning on as many LEDs as you could have on at one time.
1K would limit base current to (5V - 0.7V)/1000 = 4.3mA
You need a lot base current with 2n2222.
Remove the pin 2 to 19 connections.
Add in 100nF caps on VCC pins to gnd. Got some fast data moving here.
Use these pins for SPI, none of that shiftout nonsense.
13 = sck
11 = mosi
10 = oe
1st one would be better.
However,
Drain to Source On Resistance (Note 2) Rds (ON), VGS= 10V, ID= 3.4A Need a Logc Level part that switche full on at <5V.
very sorry for the delay in the reply, at a school tech competition.
That looks great, im working on a final prototype, do i hook up the MOSFETs the same as i would an npn transistor? not quite sure. Is there anything else i should take into account in my final design? Thanks.
hookup mosfets the same way - 100 ohm resistor between arduino pin & gate, 10K resistor from gate to ground to ensure mosfet is off when arduino powers up.
ok so i have a final version of the board. i attached a photo of the breadboard view and pcb view. What did i miss? what needs to be changed? I also included the file if you have fritzing, i dont think those pics are very good.
Also if everything is good what is a cheap alternative to fritzings fab service? I think this board would cost something like 200 bucks, which i dont have. Ive looked at your Bobuino, what did you use? thanks.
iteadstudio.com
10 boards up to 100mm x 100cm, $24.90 + shipping (~$5)
I can't tell if you used a ground plane on both sides of the board, will make routing easier.
Same for a schematic for review - can follow the fritzing picture to a point, then can't tell what it's doing.
wow, that site is a great find. I looked forever last night and couldn't find anything for under 100 bucks. I've triple checked my connections and added 3 caps for where i hook in to the +5v. added the 100 and 10k resistors. added a few headers for the audio and button input. added those 100 nF caps at the ICs. ummm sorry just thinking on screen. anything else? Im using a power supply my dad got from Seattle City Light's junk warehouse, i have it hooked up to the +5, and it says it can provide up to 12 amps, which i think is a bit overkill, but hey it works. Do you think this is acceptable? (sorry for all the questions, im on a never ending quest for knowledge) So last minute checks? all good? thanks.
yeah sorry, fritzing displays everything on one layer, the yellow traces are the top and the orange are the bottom. I cant seem to get a nice high res pic, but this thing that i did, the ground fill, put a huge sheet of copper over the top and bottom that connect everything that needs to be to ground. it did this for both sides. this what your talking about?
are you talking about the pin 19 to 3, 18 to 4, and so on? cause they are there, just really hard to see because i have both layers showing and all of those connections are on the back, so the top obscures them.
