Circuit Design from UNO board to ATMega328 without board

I am, for some reason, having a problem when taking my ATMega328 chip off the UNO board. I am guessing my pinouts are wrong or I am just unsure which go where. :frowning: I am using Pins (digital pins): 4, 8, -10, -11, 13. That’s it! It’s a pretty simple shift register, can someone help me figure out how to place the 328 directly on the breadboard to get rid of the UNO board?

Attached is the simple design. May not look pretty because I am no layout designer… but it should serve the purpose :slight_smile:

In addition to Power, Ground and several bypass capacitors the UNO provides a 16 MHz ceramic resonator (required) and a pull-up resistor on the Reset pin (should be optional). Did you provide a resonator or crystal when you took the ATmega328P out of the UNO?

I put power and ground, but added nothing else :( I thought I read that it had an internal oscillator. Can you point me to a schematic that might show this? I will have to purchase the oscillator, but have everything else.

Thanks for the reply.. I was thinking that could be the case, but haven't found anything supporting that thought (probably not searching well enough)

Need the 16 MHz crystal/caps or resonator if the part is to be used as an Uno.

Makes sense. I may have to make this my second revision :slight_smile: I’m running out of time!

What would you suggest to wire up RGB LED’s remotely? Example: I will have the RGB’s 12-24 inches away from the circuit. I would LOVE to have the RGB wires pretty much covered so that I could place them in some sort of clear tube all together, but wired out one side (hope that made sense). I drew it up and attached in case it was unclear :slight_smile:


Use some ribbon cable to go from shift registers over to the LEDs.

3 of these
few lengths of this
and split it up as needed to the individual LEDs

ok, that sounds easy enough on the shift register side of things. What would help on the ring side of things? I am not quite sure how to get these wired without the RGB leads touching each other inside the ring. I think that's where I am confused most after hours of searching :(

The LED leads are pretty stiff once cut short - cut them to the length needed, and solder the wires on to the pins. Can also put shrink wrap over each pin. Slide a length down each wire, solder the pins, slide shrinkwrap up & heat it up.

------------------------------------------- LED1 R ------------------------------------------- LED1 B ------------------------------------------- LED1 G ------------------------------------------- LED1 CA ---------------------------- LED2 R ---------------------------- LED2 B ---------------------------- LED2 G ---------------------------- LED CA ---------- LED3 R ---------- LED3 B next wire ---------- LED3 G ---------- LED3 CA ----- LED4 R ----- LED4 B ----- LED4 G ----- LED4 CA - LED5 R - LED5 B - LED5 B - LED5 CA

next wire, etc.

Thanks! Just picked up shrinkwire, actually... only because I saw it in the store, have a heat gun, and thought to myself I can't believe I didn't figure that out already. Thanks again for all of your help!

No problem. Post a pic when you get it working.

Your "off/on dip", assuming that is a switch, is wired incorrectly. You need to add a 10K resistor between pin 4 and GND so the input is not left "floating".

Enabling the internal pullup means the input will be HIGH unless the switch is pressed to make it LOW. No external resistor needed.

I am so slow at this. It's a pain in the butt to solder the ribbon cable to the RGBs and then heat-shrink properly. I think I need more tools :) And a magnifying glass now that I'm semi-old (42). Now I wish I would have been 'on top of' this project when I started it. I would have had a real PCB created and some connectors to make this much easier!

Live & learn. Plan better next project.

Good advice :)

Question: I have soldered and wrapped all the RGB's. It is possible while soldering that i burn out RGB's? None are working, I'll have to go through the circuit again to make sure I have it wired - but wanted to check. I assume, yes.

It could also be the ribbon cable as I elected to go with the plug: It doesn't clamp down well, so possible that a wire isn't properly exposed to the pins. Gotta check that too.

Possible, yes, you'd have to keep the iron on the pins for more than a few seconds to do that.

Have small vise? Use that, with a spacer on the pin side, to squeeze it together well. Buzz the connections from pins to LED leg, make sure you have good connections. Also possible your breadboard connections are just on the opposite side of the clamp-on connector.

ok, got everything working :) I've attached the circuit image again and was hoping I could have some help determining powering options. I need to power this circuit via battery.

I have 7 RGB LED's ( I have 3 74HC595 ( I have 1 DFRobot switch (

I was trying to compute max current, so came up with this:

7 RGB * 120mA (peak) = 840mA 3 74HC595 * 160uA = 480 uA 1 DFRobot Switch = 100mA Arduino UNO Board = ?

Is this how I would sum it up? And then once I got the sum, how do I determine the right power for continuous load?

thanks again!

forgot to attach :slight_smile:

Okay you need current limiting resistors between the LEDs and the 74HC595.

The 74HC595 is only good for 70mA total, so if you were to turn on all 8 LEDs at once connected to a HC595, you’d want to limit the current to each to <8.75mA.

24 * 8.75mA = 210mA total for LEDs max.
Arduino, 20-30mA
IR switch,100mA if you say so link is not opening for me.

So a 1A wallwart would fit your needs easily.

or a 2A, looks like its less:

ok, that makes sense.

However - I need to calculate the max load and determine how long a battery pack (and what battery pack I need) would last :)