next topic »

[Reply #120 on:]

So one could hook up independent devices and be sure to have a ground connection available for it.
That's one of my peeves with the Promini; connect up power/gnd, Rx/Tx/Gnd out to a connector, and you're down to 1 gnd for anything else.
What good is a small processor if you have to do all kinds of wiring fooling around to connect to it?

[Reply #121 on:]

ah makes sense - anyway i have some ideas on how to use the boards but ill have to wait for the atmega328 to arrive

[Reply #122 on:]

Won't the '8A do what a '328 can do, you just have less memory to do it in?

[Reply #123 on:]

yeah pretty much the same but im running low on atmega8 too the board i assembled today uses atmega8

[Reply #124 on:]

@CrossRoads,

 I bought some reset switches but, although small they are too big. Can you tell me what to use for these boards?

I have 2 built to the point that I think they are ready to program but, it maybe a day or two.

[Reply #125 on:]

The board wasn't intended to have a switch installed on it - just wired to one off board if needed.
Reset is mainly there to allow programming via AVR ISP programmer, or via serial download using USB/Serial adapter.

[Reply #126 on:]

I just thought I'd share this board I've been sharing in other threads of the community:
http://arduino.cc/forum/index.php/topic,71375.0.html

Given that this initial post was about "Very Small Arduino", I thought I would also share it with you here too.

The arduCHIP is a small compact board and breadboard-friendly based on the ATmega328. It has more or less the same functionality of the Arduino, but in a very small and compact package (20.6mm x 25.8mm).

It requires a 4.5-5.5V, or 1.8 to 4.2 if you run it at 8MHz, regulated power source making it the perfect companion for the arduSTAMP. The serial interface is fully compatible with the USB breakout board of the arduSTAMP or with sparkFun's FTDI basic. It also has a reset push button when prototyping and downloading.

The arduCHIP is meant for users that are familiar with the Arduino environment and are looking for a cost effective bare bones board to use on a space and budget constraint project (less than 7€ BOM including PCB). If you are not familiar with the Arduino environment it is recommend that you first go for the Arduino Duemilanove, the ONE (they are great boards and a very good starting point) or even the arduSTAMP. arduCHIP does not come with header connectors assembled (only the ISP and UART header) so that you can solder in any connector with the orientation you need for your application.

Here is an image of the IO mapping and PCB.


The entire project is opensouce, Eagle CAD files and an Eagle library file (to simplify using the board in any project) can be downloaded from:
Wiki page: https://bitbucket.org/fmalpartida/arduchip/wiki/Home
Download page: https://bitbucket.org/fmalpartida/arduchip/downloads

I have currently run out of boards but there is a new batch coming.

If any one is interested in the PCBs, I've currently run out off but will be receiving an additional batch soon. I am sending them for:
- 2,2€ - bare board
- 13€ - fully assembled board

This includes shipping using regular snail mail.

Here are some images of an assembled unit.

[Reply #127 on:]

The arduSTAMP Rev A.2 have arrived today. The boards look great and are working like a wonder.

Surprisingly surface finish of the boards have been done ENIG (Electroless Nickel Immersion Gold)! The quality of this batch is extremely good.

Hear are some pictures of the boards.

For all of you waiting for Rev A.2 to arrive, they are now available.

[Reply #128 on:]

The arduSTAMP Rev A.2 have arrived today.

 How much would it be for 3 shipped to USA 62246? In US dollars please.

[Reply #129 on:]

Bare boards are going for 2€ each + registered mail to the USA 3,10€. Current exchange rates today: 1 Euro = 1.3795 U.S. dollars.

[Reply #130 on:]

I'm sorry but I don't quite understand why you would need more than 1 ground pin? 
Why can't you just connect them to the same pin?

[Reply #131 on:]

I'm sorry but I don't quite understand why you would need more than 1 ground pin? 
Why can't you just connect them to the same pin?

I would assume for flexibility. You will likely have several components that would need a connection to ground, so allowing multiple connection points to the ground plane means not having to solder more than one lead to the same hole. I know I would do that, if I was ever designing a board.

[Reply #132 on:]

oh that makes sense

[Reply #133 on:]

Yep, that is correct, the reason behind putting extra GND pins was to give users a bit more flexibility. Most projects tend to use the ground plane pin often, so... Also, if you are using a USB to UART you would have to share that pin with the rest of the project, making it a bit un-friendly, ... By having multiple ground pins you can leave a ground pin dedicated to that  UART to USB (for example).

[Reply #134 on:]

So there are multiple connections, but only one ground plane