Newbie help need for production

Hi I am brand new to Arduino and my apologies if this is already covered elsewhere. I am not very familier with microchips and their requirements.
Inhave completed my project on a UNO board. I want to know if there is a cost effective board I can buy ± 25 that I can deliver with my product. An Uno would be too expensive.
All the board nees is Power, 2 analog inputs, 1 button input and the ability to write to a 4 character LCD

I would want to put this into an enclosure powerd by 9vdc battery.
Any help would be appreciated.


What's the interface (or model #) of the LCD?

Unless I am just missing the intent, take the 328P out of the UNO, put it on a board with an LDO Voltage regulator (and associated components) and you are in business. You will need the LDO because a 9V battery will only let you use a small percentage of it before the regulator will no longer convert the voltage. The LDO will greaty increase your battery usage.

You already know what pins are needed for what since it is all working with the UNO. For somthing this simple, you don't need to have a custom board made. Just use wires to connect everything. I would recommend getting a socket for the chip in case you run into programming issues. It would suck to have it hard soldered to a board and have to re-program it. While it is possible usng the Arduino as a programmer, the socket just makes it easier.

When you are done, buy another chip from Sparkfun, they have them already loaded with the Bootloader for $5.50. Stick it in the UNO and you still have your rather expensive UNO for your next project development.

I am convinced that this is a major misconception about AVR chips and the Arduino. I am an absolute newb at Arduino having come from a PIC background and I avoided Arduino for the longest time for exactly this reason. I was always convinced that you have to have the Arduino board in your finished project. You don't.



This little board will do the trick for you. Can buy the needed components from pretty inexpensively. they have bootloaded processors too. Get an FTDI basic for the USB/serial adapter for downloading sketches.

When you are done, buy another chip from Sparkfun, they have them already loaded with the Bootloader for $5.50.

Just a note on that - you can get blank chips much cheaper, Digikey has qty 25 for $2.47 ea:

and it's really easy to burn the bootloader yourself with Westfw's excellent Optiloader:

Good luck!

I think it's even possible using an atiny and controlling the LCD via I²C. there are examples of how to program the atiny using your arduino.

Yes they can be had cheaper but Bootloading for the novice (read me) can be a confusing topic that's why I find it worth the extra couple of bucks to get the one that is pre-bootloaded without having to yet learn those extra pieces of the puzzle.

As far as the ATTiny. You run into a couple of the same problems. For the beginner, programming the ATTiny is not quite as obvious as sticking a 328 in the UNO. Also, unless you buy the serial 7 segment display you are not going to be able to I2C it. And the cost difference between the Parallel and Serial displays is profound when you consider the minimal cost savings of going from a 328 to a tiny.

So for the absolute beginner as the OP (and myself) claim to be, the 328 is the way to go. Simple, yet elegant and CHEAP! Almost any enclosure that will hold the 4 digit 7 segment display will be big enough for the 328 and its peripherals.

I am developing on the UNO right now (I have had it for exactly 3 days but have researched it for a long time now) but due to size constraints will ultimately move to the TQFP package so all of these things will soon become very important to me but for now, as a novice, simple is better.

If you need a little board with minimal parts for the TQFP, take a look at the Mini-uino at my signature link.

Thanks Imagree, simple is better and 2 bucks is no big issue. I ordered them and the boards which were $1.75 each. Thanks for the help..

Well the money saved by installing the boot loader yourself depends upon your business model, but do you really need the boot loader? It is possible to take the HEX file generated by the compiler and burn that directly into the processor. It will run your code every time you power it up. You won't be able to update the code using AVRDUDE, you would need a programmer. But you seemed to indicate you won't have a USB interface anyhow, so why not just deploy your product without a boot loader at all?

Crossroads, even your board is too big. I have to fit a lot of components into a very small space. This includes a tactile switch with a cap, an Xbee and a Coin cell battery. even going 2 sided I am struggling to cram it all in. The XBee is killing me so I have been looking for other, more cost effective solutions for wireless comms.

In fact, I bought one of these to make this a lot easier. I actually bought the last one they had in stock. Could not beat $25.

For the OP. Sorry to hijack. Keep us updated on your project.


1.3" x 1.3" is too big?
Well, The extra grounds can be deleted, 0.5" pins can be used, the xtal can go surface mount, the parts can go down to 0603.
Instead of TQFP, the even smaller leadless package can be used for the '328.
I don’t see how that huge socket helps.

The socket is merely to build a programmer. Sorry that was misleading. I was struggling with the challenge of having to program the TQFP package off board. I was going to build the ISP into the board until I ran across a post on the Jeenode site where he uses that socket for a programmer. Even a 2x3 header on my board was a lot of real estate I couldn't afford. I toyed with the idea of bringing the ISP out to a mini A usb connector but had the same problem and wasn't sure I could pull that off due to pin counts. It would have been nice to have the option of updated the software but it wasn't critical.

How many of these are you building? You can buy your processors already programmed from DigiKey.

If you are bringing the pins out to IOs that you can access, you can make an adapter cable & connect your programmer up that way also - as long as whatever you have on D11,12,13 are not outputs that will interfere with the programmer.

skyjumper: You won't be able to update the code using AVRDUDE, you would need a programmer.

This is incorrect. The programmer uses avrdude to upload code (and to do things like burn a bootloader).

Perhaps you meant you'd be unable to upload code without a programmer?

I think for a newbie who's realized they don't need to imbed an actual Arduino board in each project, a good step is to learn about how to use an ISP. It's not that complicated - take a look at

Not to mention you'll need to be able to do this if you want to program TQFP's. I don't think anybody sells them with a bootloader (well, I'm sure you could pay Digikey to load software for you, but probably not in the quantities you want).

Welcome to the world of the $5 "Arduino" board...Look ma, no shields!


Brad (KF7FER)

[quote author=Brad Burleson link=topic=87881.msg662090#msg662090 date=1327193320]

skyjumper: You won't be able to update the code using AVRDUDE, you would need a programmer.

Perhaps you meant you'd be unable to upload code without a programmer?


Yes, that's what I meant. He would actually need an ISP and some software to drive it, like AVRDUDE, AVR Studio or whatever.

I still don't see why he needs a bootloader.

For the OP, the idea behind buying the pre-bootloaded chips is that he already has the Arduino UNO. For him its as simple as plug and play. No bootloading, no ISP, no programmer or programming cable. He can simply pull the chip out of the UNO when he is done and stick it on a board. I have 7 different components to my project and this is exactly how I am prototyping. It is super easy and low low cost at $5.50 each.

For my purposes, I never expected to get the TQFP preloaded and always anticipated having to program them myself. Luckily the UNO serves this purpose and I bought that socket specifically so I could easily connect to all the pins I needed. What I think I will do is solder directly to the back of the board the socket comes on and bring those out to a 2x3. Not the prettiest but Frankenstein is what this is all about.

If you need to program TQFP chips, take a look at this post on the Jeenodes site. This is where I got the idea: