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1  Using Arduino / Project Guidance / A customized Arduino Nano breakout board on: June 03, 2011, 11:05:10 pm
Hi there,
I need to create a dedicated 'break-out' board for the Arduino Nano.

It needs to connect to:

8 digital switch connections - some are two way toggles- some are three way toggles.
4 leds
4 analog pots
1 battery (for purposes of reading the voltage)

I have decided to use screw terminals to connect the various components to a PCB.

One 8 point screw terminal for 5v feed to the digital switches and the analog pots. This would not be enough if all digital switches were two way, but some are three way, and therefore have three connectors, with only one 5v common.

One 8 point screw terminal for Ground to connect the analog pots and the LEDs.

One 8 point screw terminal for the 8 Nano digital switch connections.

One 8 point screw terminal for the Nano digital connections to the four LEDs and the Nano analog connections to the four analog pots.

One 2 point connector to the battery.

The battery gives out a maximum of 16v. I am using a simple two resistor voltage divider to feed the divided voltage into an analog Nano input.

The LEDs are all connected to 5v resistors.

The digital switches are all connected to resistors. I had intended to use 4.7k resistors.

It ends up being quite a complex circuit.
I've mapped in in Fritzing, and will order a PCB.

Obviously I don't want to order PCBs made, and then find I've made a stupid mistake.

I think I've got it all right, and attach a circuit diagram. I'm afraid the Fritzing schematics are not the cleanest, but I hope it makes sense.

Does anybody see any problems with this?
Am I right to use 4.7k resistors, or would the standard 10k be better?
Can the Arduino Nano handle this many connections?
Will my voltage divider be okay, and not fry the Arduino?

I would be most grateful for any feedback. This is the first time I've used the Nano.

Thanks a lot.

Paul


2  Using Arduino / Interfacing w/ Software on the Computer / Re: Standard Firmata with blink on: May 29, 2011, 06:40:35 am
Thank you.
That makes sense.

Since the VB.net program is going to be doing a lot of other things, I wanted to reduce the processing burden as much as possible.
That's why I liked the idea of the blink timing being done by the Arduino.

I wonder which is the more efficient way of doing it - using the Firmata protocol, with VB.net controls, and put a timer in the program, or do it via Serial control and put the timer on the Arduino?

Paul


3  Using Arduino / Interfacing w/ Software on the Computer / Standard Firmate with blink on: May 29, 2011, 05:04:04 am
Hi,
I need to access switches and control LEDs from within VB.net.

So got an Arduino Nano.

I am a totally new Arduino user, and so am still a bit ignorant.

I had thought I would use the Serial Control, and create my own sketch.
I have got switches to send messages to the Serial Monitor, and I can send triggers from the serial monitor to switch LEDs off and on.

I was particularly proud of myself, when I managed also to incorporate a blink loop, so that the LED could be set to flicker when triggered on.

But then I found Firmata.
This would seem to take a lot of the programming work away, giving a control that will drop straight into VB.net.

So I tried this, and sure enough, I can control LEDs, and read switches using the Firmata Standard sketch.

But...

I can't even vaguely work out how to use Firmata to set the LED not to just stay on constantly, but to blink/flicker at a preset rate.

I thought I might be able to take my blink routine from the original sketch, and stick it somewhere in the Standard Firmata sketch to control the flicker on the digitalWrite line.

However, I can't even find a digitalWrite line in the Standard Firmata sketch.
I can't find any line which is switching on the LEDs.
So I have no idea how to make an LED blink.

Is it possible? Is it complicated? Is it worth it?

Or should I go back to my original idea of coding my own sketch and communicating via Serial?

Any help gratefully received.

Thanks.

Paul

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