Any solderable proto board that fits the Pro Mini

Using Arduino Project Guidance
1

Hello, it's been a long time since I've posted here. Many things in life getting in the way, but finally a real life job involves using Arduino.

I got a gig working for an "escape room" and I want to use a Pro Mini in a couple of spots. I have need to solder the board down, but I can't find any solderable prototyping circuit boards that properly fit the footprint of the board. Does anyone know of a protoboard that is set up for a wide footprint and allows several pads on each side to be used? Everything I can find pretty much is set up for .3" width chips, but the pro mini is .6 or .7 wide. I don't really have a need for the holes at the end or the odd ones for the extra analog pins. I just want to have 3 or 4 holes open along the sides, just like what you get when you plug a .3" DIP in a solderless breadboard.

I don't have knowledge, time or even inclination to have custom boards made. I'm just hoping someone else has already done it.

2

The great thing about the Pro Mini is that, unlike the idiotic Arduino Uno style headers, all the pins other than A6 and A7 are on the standard 0.1 inch grid. So any prototyping board will work. My favorite style is this stripboard with the solder mask over the strips to prevent solder from creeping down the traces, making everything look super messy:
http://www.ebay.com/itm/282029976127
that seller is on vacation right now(maybe Chinese New Year?) but you could probably find another listing for the same thing if you search around a bit.

If you're going to work with stripboard I recommend you buy a stripboard tool also, something like:
www.ebay.com/itm/290941443967

You can make your own from a drill bit or cut the tracks with a utility knife too but when you're using stripboard a lot it's nice to have an easy to use tool for this.

3

I bought this ridiculously cheap lot just yesterday.

4

My favourite kind is called tripad board. It's like strip board but the strips are broken up into groups of 3 holes. It takes some thinking to use it in the best way, but you don't need break the strips yourself. It's not easy to find but you can get it in Maplin or Clas Ohlson in the UK.

tripad-board.jpg
tripad-board.jpg515×515 42.5 KB

5

Get a suitable IC socket for holding the Pro Mini - in case you change your mind :slight_smile:

...R

6

I'm not sure an IC socket is such a good idea, but standard pin strip would be fine and my Pro Mini came with the pins.

7

Yes, it has already been done, and well too. I've found these pro-mini specific proto boards from one of our regular contributors here to be a real time saver:

While it may be a dollar more than a blank board, it will pay for itself many times over in the time saved when it comes to mounting and wiring all the typical parts you'll want in addition to the pro-mini. Dr Azzy's stuff is very well thought out and of good quality. Highly recommended.

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Nick_Pyner:
I'm not sure an IC socket is such a good idea, but standard pin strip would be fine and my Pro Mini came with the pins.

I'm curious as to why not?

I am assuming you would solder the pins on the Pro-Mini in the usual way and then plug it into a suitably sized IC socket?

...R

9

IC sockets are made for ICs. I have never seen an IC that has pins like a standard Arduino header, or a header with pins like an IC, so it might not be a surprise if an Arduino header pin will not fit in an IC socket. What I can tell you is that an IC will fit in a pinrow but don't bother turning it upside down because it will probably fall straight out, hence the caution.

10

Nick_Pyner:
but don't bother turning it upside down because it will probably fall straight out, hence the caution.

I just tried some of the legs of a Pro Micro in an IC socket and they seemed to be gripped securely. I admit that is not an extensive test :slight_smile:

...R

11

Any problem might be more apparent after you have pushed in for the fourth time....

12

I'll add that I've never seen an ic socket that could withstand the .025" square pins used for connecting the Arduino type boards. A .100" center female header yes, but never an ic socket. Now if you're using strips of .020" round pins for interconnects, then yes, they work very well together with round female machine pin ic sockets. The only standard socket compatible pin I've ever seen is this rather pricey but very clever and robust design:

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avr_fred:
.100" center female header yes,

Probably a wiser choice :slight_smile:

...R

14

avr_fred:
Yes, it has already been done, and well too. I've found these pro-mini specific proto boards from one of our regular contributors here to be a real time saver:

https://www.tindie.com/products/DrAzzy/project-board-for-arduino-pro-mini-/

While it may be a dollar more than a blank board, it will pay for itself many times over in the time saved when it comes to mounting and wiring all the typical parts you'll want in addition to the pro-mini. Dr Azzy's stuff is very well thought out and of good quality. Highly recommended.

That's a pretty impressive board. It's a bit more capable than I really need, but the price is decent. I'm not into surface mount parts, but I know plenty of people are. If they just made an SB300 type board with a wider stance, it'd be perfect for me.

I don't mind soldering the board down as long as I can still flash it in circuit. This brings up a noob type question. Is there a tutorial explaining what I need to know and observe when it comes to flashing the board in circuit where the board will already have a 5V regulated supply available? I'm wondering if I should disable that power and power the board through the horizontal pins that you flash it with, or just leave the Vcc pin on the flash header disconnected from the USB to serial adapter and leave the other power applied. In case you can't tell, I haven't touched this stuff for a few years now and I've forgotten a lot of these kinds of details.

Basically, what I'm doing is using the Arduino to handle a bunch of pushbuttons and then when the user puts in the correct sequence, I'll drive an output pin high that goes to the base of a 2n4401 transistor that enables a 12V automotive relay. The relay will have a protection diode added to prevent spiking the collector of the transistor when it turns off.

All I have available is a 12V DC supply coming into the cabinet. I was thinking of using a 7805 regulator on the board to create the 5V supply I need for the Arduino. I'm a little leery of connecting the 12V supply directly to the RAW input of the Arduino, should I be? I mean I know that the "official" pro mini is supposed to tolerate 16V, but my boards are made by Inland (Micro Center purchase) and I'm unsure if their regulator is okay with that much voltage, they only specify up to 12V. Of course a 12V wall wart tends to run a little above that, and I'm always one to treat maximum specs as something you should never reach, much less exceed, even if it is just a tiny amount.

If I feed a regulated 5V into the Vcc pin, can that harm the onboard regulator if nothing is connected to RAW pin? A 7805 can suffer greatly from doing something like that, so I'd rather not have to include my own regulator if I don't need to. I guess I should just try feeding 12V into the RAW pin of one of my boards and see what happens.

Here is the board I'm using:
http://www.microcenter.com/product/431996/arduino_pro_mini_board

15

afremont:
I don't mind soldering the board down as long as I can still flash it in circuit. This brings up a noob type question. Is there a tutorial explaining what I need to know and observe when it comes to flashing the board in circuit where the board will already have a 5V regulated supply available?

power is not usually a problem. What is a problem is if you have anything else connected to pin 0 and 1 (the serial programming pins.) If your circuit uses those pins then you need a way of disconnecting the Mini from the circuit when programming.
(Reset is also required but it's rare to use the reset pin in any Arduino circuit.)

All I have available is a 12V DC supply coming into the cabinet. I was thinking of using a 7805 regulator on the board to create the 5V supply I need for the Arduino. I'm a little leery of connecting the 12V supply directly to the RAW input of the Arduino, should I be? I mean I know that the "official" pro mini is supposed to tolerate 16V, but my boards are made by Inland (Micro Center purchase) and I'm unsure if their regulator is okay with that much voltage, they only specify up to 12V. Of course a 12V wall wart tends to run a little above that, and I'm always one to treat maximum specs as something you should never reach, much less exceed, even if it is just a tiny amount.

If I feed a regulated 5V into the Vcc pin, can that harm the onboard regulator if nothing is connected to RAW pin? A 7805 can suffer greatly from doing something like that, so I'd rather not have to include my own regulator if I don't need to. I guess I should just try feeding 12V into the RAW pin of one of my boards and see what happens.

Well, if you need to know what components were used for the regulator, then you need to buy from an official source instead of a knockoff. It's probably OK to feed 12V straight to the Mini and it's also probably OK to feed 5V in without disconnecting the old regulator. The reason for choosing either method is the power dissipation in the regulator when all power-hungry outputs (relays and LEDs) are turned on.

16

I'm thinking I'll just put one or two 1n4148 diodes in series with the 12V before it gets to the Arduino to protect against reverse voltage and to drop the 12V down a little. The pro mini will only be dissipating a tiny amount of power (just what it takes to run it and its onboard LEDs). I'm going to use a logic level mosfet for the output pin which will more than handle the switching of the 12V automotive LED light panels (not using a relay now). The 3 12V light panels each need about 190mA (yes they're ridiculously bright). Since this is a one-off, I'm not concerned about overkill on some of the parts, I'm more concerned about reliability and idiot proofing it to some extent.