moving from Uno to Mini Pro, vcc

Other Hardware General Electronics
1

Hi,

I'm inexperienced so please forgive me if the answer to this question is too obvious.

I'm moving a project I was prototyping from my Uno to a mini pro. I was using a breadboard with the Uno and had an RFID reader and a photoresistor both drawing power from the 3.3v pin and it was working as i wanted.

I will be soldering wires now and have no idea if I solder a patch for each of the RFID and photoresistor into the vcc pin (so, two wires on one pin) or, if i need to achieve this differently.

I'd be grateful for some advice or a link to where I might learn more. Everything else seems more or less straightforward to me.

thanks

2

Is the promini running at 5V? Where will 3.3V come from?
If running at 3.3V, the regulator is only good for 150mA.

3

i can get a 5V mini if that's preferable.

I appreciate your response here, CrossRoads. If i did have a 5v? what would my next best step be?

Please and thanks

4

If it's a 3.3v pro mini, use Vcc - BUT be aware of the 150mA limit.

If it's 5v, or you need more than 150mA, you need an external LDO regulator.

5

If you mean you are going to solder components to the Pro-Mini I don't advise it. The standard convention for uP is to have a connector (preferably a Phoenix screw connector) and an interface cable and a separate prototype perf board. Everything that is not part of the factory made Pro-Mini gets installed on the prototype perf board (or custom PCB) and the interface cable from the peripheral board (the added board) is a ribbon cable that has female headers that simply plug into the male header pins already on the Pro-Mini (assuming you installed them) . You should start your post with a photo of your Pro-Mini and a list of what you want to add to it and how you planned to do that (where you planned to install the added components).

6

DrAzzy and Raschemmel,

Thanks for these posts. I will receive my pro-mini in the mail soon i hope. I can then add more info but perhaps I can start this convo by adding a pic of what i have working on my Uno. I just want to solidify connections so I can ultimately compact and protect things. It's for an art installation that has to run all night so, from my understanding, a pro-mini is a better choice for that kind of job than an Uno.

As well, i'll likely make a back-up or two. I can see staging the piece again at some point but, for sure it must be able to run for 24 hrs connected to a PC.

thanks

7

Interesting point.

We are telling people you cannot use the auxiliary regulated 3.3V from Unos, USB to TTL converters and the like to power sub-assemblies such as the ESP8266 or RC-522 RFID boards, yet I see YouTube videos demonstrating exactly that with apparent success.