Want to make an Arduino Mini-kinda Clone?

There is only one board. That's why I wondered if I should do it on the board. Instead of

I'll have a button that will control a couple solenoids and possibly make some decisions based on other sensors.

I just don't want the solenoids doing anything they shouldn't.

Until I want them to.

I am interested to modify the Arduino Mini to use Atmega328 and also make use of the two extra pins on the PCB. Since I am new to Arduino, I would like to take suggestion from all of you and publish it in the open source after it is done. Thanks in advance.

Kan.

Was your reply a question or a statement?

What two extra pins are you trying to use?

You should be able to ninja from the eagle files on the main site. Then modify those to what you need.

I'm assuming that if you use this for commerical purposes, you have to meet the licensing requirements... Which I think amounts to giving credit on where the original came from.

Thanks for your reply. It is a question since I am getting suggestion. The Mini board I had in mind will be the same form factor as the Mini and Pro-Mini. I have everything figured out and I also want to use the two extra pins, pin 19, 22 and attached LED and push switch on these two pins on the pcb. I also thinking of removing the regulator so that to reduce cost. The finished PCB will plug into a standard 24 pins DIP socket. Can this be feasible?

Thanks,

Kan.

I suspose anything is feasible. I'm not sure that you will be able to fit two more switchs and an extra LED plus 2 pin outs in the same formfactor of the mini-pro.

It's fairly type as it is.

I haven't tried to put one into a dip24, since that isn't want I wanted. I'm not using most of the pins.

The smallest I had my eagle files and was able to successfully route all the wires was .7x1.2" or so. My current layout is .8x2", because I added the pinouts to be able to burn the bootloader and program via usb programmer.

This is my Rev, I want to make sure it is going to work. Before I start subtracting parts to make it smaller. The smallest that I think that I can make it. While staying on a 2 layer board and keeping the connector I want. Is about .7x1".

Pins 19 and 22 are ADC-only. They do not function as digital I/O pins, so you can't run leds with them, and you would have to use analogRead to use a switch with them.

As for your pin 13 weirdness, I can confirm that the bootloader treats pin 13 uniquely, defaulting it to output mode and blinking it on startup.

Thanks for your answers and I almost make a big mistake. I am surprise to see Atmel didn't get a port properly and make them ADC only.
I am going to modify the design and should make it final. I will remove the regulator circuit and just pull out the pins of 19 and 22. I am not going to add any more LED nor switch on it. It will fairly comfortable under one buck.
My board will be the same size as the Pro Mini and that is 0.7x1.3".
I'll put the ICSP socket outside so that I can also program the bootloader/program if needed.
The remaining question is whether I should use 6 pins or I can use 5 pins for the serial/power/DTR port? Any idea about the CTS pin? Should I leave it or I need to keep it? If I use a 5 pins one, then I can make the board 0.7x1.2", I hope.

On the mini, the CTS pin is connected to ground. The only reason it's there is for compatibility with TTL-232r cables. Other UART devices like Sparkfun's FTDI Basic Breakout use the same pinout so that they can be used interchangeably. You can get rid of it if you want, but you'll be making it a lot more difficult to connect a serial cable for programming.

Thanks for your quick reply.
Can you tell me what a TTL-232r cables? I am planning to build a USB to serial FT232RL Mini USB adapter that fit this board.
Thanks,

It's the cable that the FTDI Basic Breakout pinout is based on. The mini is designed to use either of these for programming.

Thanks for your quick informative replies.
On the document, they said that FTDI use RTS to generate the reset and Spark Fun uses the DTR for reset. If there is any preference?
Thanks again.

DTR seems to generally be preferred if it is available. Recent versions of the Arduino IDE assert both pins when it is trying to reset the Arduino. I thought I read somewhere that RTS could possibly be pulled low at other times (causing unexpected resets), but I can't find the reference, and if there ever was such a problem, it may have been fixed. From what I can find, it looks like the choice of DTR over RTS is a historical one. It was chosen for reasons that are no longer relevant, and RTS support was added later to make it fully compatible with the TTL-232R cable.

Thanks for the quick replies again.
OK, I'll select DTR as the reset generator.
I am happy and comfortable for my design now.
I hope I can fit it in a 0.7x1.2" board.

I did some more research. Apparently, RTS works out-of-the-box on OSX and linux, but requires a configuration option to be set to work under windows.

RTS auto reset has never worked for me on linux.

That's why I've retired my FTDI cable and switched to the BUB, which provides DTR.

Thanks for your help. I think I will settle for Windows only.
I will use only 5 pins including DTR and the board should be able to fit in 0.7x1.2".
Thanks for your support again and will keep you posted.

Well I jumped in with both feet.

Ordered the components. Will order the boards tomorrow.

Hopefully, I won't have a pile of melted bits when I get done.

Ok....

So I got my boards from batchpcb.com, took about 2-3 weeks.

They are soooo cute. muhahhah

Anyway, I ordered 5, they sent me 10. Which is cool.

Now my question.

Do I need to do anything to prep these? Do I have apply solder to the shiny solder mask area things.

I have extras, so I can screw up. But I would prefer not to.

I watched the pcb solder tutorials, so I think I have the soldering under control. I just need to know what prep work needs to be done.

Thanks.

The silver spots have a thin layer of solder already applied to prevent the copper from oxidizing, but it is not enough to hold your components on. You will have to add solder as you place components, and don't forget the flux.