Arduino Nano v3.0 - $7.59

[pixel5]

http://arduino.cc/en/Main/ArduinoBoardNano

This looks like it could do the same thing as the teensy I just paid $15 for... Am I right?

mod edit: vendor link edited out -- that particular vendor has been harassing members on the site and is banned.

[SpAmRaY]

I can't get to that website at work but I believe there was some discussion on either this controller or a similar one recently. I can't seem to find it at the moment however.

[regack]

The main difference that I recall is the atmega32u4 has native USB support and the atmega328p does not...

[pixel5]

The main difference that I recall is the atmega32u4 has native USB support and the atmega328p does not...

Then why would it have a mini USB port built into it?

[Soarer]

http://www.banggood.com/Wholesale-Mini-USB-V3_0-ATmega328P-AU-Microcontroller-Board-Arduino-compatible-p-68535.html

This looks like it could do the same thing as the teensy I just paid $15 for... Am I right?

No.

The main difference that I recall is the atmega32u4 has native USB support and the atmega328p does not...

Then why would it have a mini USB port built into it?

It can run USB emulation in software. Not as good as having USB hardware!

For a controller, software USB might be OK, but for a converter it's really not ideal. A converter has to respond quickly to both its input and the USB, and that's hard to do if they are both in software.

[mkawa]

yah, so it depends on your application. atmel makes so many different freaking micros agh!

for some very large application types, this is enough, and a teensy is overkill. another way to look at what soarer is saying is that for say, his protocol converter, the ardnano is no good.

imo the major difference is not really the micro platform but actually the libraries supported. the teensy library is particularly nice. the arduino library is good, but the teensy library adds a bit of nice abstraction over it for those new to embedded programming. and further, the fact that teensy code can be compiled to either the 8-bit atmels or their sweet new arm cortex-based soc is pretty cool.

[oaklandishh]

I have used  nanos before and they were VERY temperamental. Sometimes I couldn't get the sketches to upload, sometimes it  wouldn't detect the arduino, and  sometimes it would just stop  the serial connection randomly.  I wouldn't recommend them, but it might have just been my bad luck. oh and of the 3 I used one was DOA.

[Soarer]

I haven't got them yet, but I ordered a few Arduino Pro Micro from HK (via abay) - currently the cheapest way to get an ATmega32U4. Downsides are the Arduino loader, and not having all pins broken out, but still a good choice for converter use or as a controller for a small keyboard.

[bcg]

I haven't got them yet, but I ordered a few Arduino Pro Micro from HK (via abay) - currently the cheapest way to get an ATmega32U4. Downsides are the Arduino loader, and not having all pins broken out, but still a good choice for converter use or as a controller for a small keyboard.

Hi Soarer I've built your converter from the Pro Micro, it works great.  Thanks for all your work and making it available to us, its really incredible!!!

Anyhow I documented the pinouts in case you're curious.  Also I *highly* recommend you use cyanoacrylate super glue to really tack down the micro USB connector as it comes off with very little pressure.  I used super glue and also added one of these for extra stress relief - http://www.ebay.com/itm/For-Motorola-Mini-USB-To-Micro-Adapter-Charger-Convert-/200489257975

[Soarer]

Nice diagram! Can I put it in my thread & docs?

Thanks for the tip about the socket. It's a shame, they spent time making the micro socket more robust inside and able to handle many more insertions than the mini socket, but then manufacturers make them so they fall off the PCB

My Pro Micros arrived, but I haven't tried one out yet. Took about 2 weeks to get here (from Shenzhen), and a couple of days ago the price was reduced by about 30%... now £3.77 shipped (about $5)... bah! Might just order some more to average down

[bcg]

For sure, you can definitely use the diagram for anything.  I put that together late at night and haven't tried the LED or AUX pins so its possible some could be labeled wrong, but I did double check the schematic so I think its ok.  I am attaching the layered GIMP file of that image in case you want to change anything

I agree about the micro connector... its really bad too because I know I've seen them with 4 mechanical solder points, definitely a design flaw to use this one on this board.

In case anyone comes across this thread and is wondering how to program this board.  After you plug it in to USB, it may not jump to the bootloader, even if there is no sketch loaded.  You might need to take a piece of wire to short the RESET and GRND pins and then "double tap" it.  Once you do that it switches to bootloader mode for 8 seconds and you can run avrdude or whatever to load your program (on Linux for some reason I have to sudo in order for this to work):

Code: [Select]

sudo avrdude -pm32u4 -cavr109 -Uflash:w:Soarer_at2usb_v1.12_atmega32u4.hex -P/dev/ttyACM0
I found the device name (/dev/ttyACM0) by using

Code: [Select]

dmesg | grep tty after plugging in the board and looking at the last entry.

On Windows you can try this:

Code: [Select]

format c:
j/k... don't do that... however replace /dev/ttyACM0 with something like com9, or whatever is shown as "Arduino Leonardo Bootloader" in device manager.

HTH

[Soarer]

Cool, thanks! I might add labels for the rest of the pins' normal names (e.g. PB6).

One option for holding the connector might be to cut the tracks to RAW and TXD pins, and then use some solid core wire to anchor the back of the connector to them. Might even work using the two closest GND pins - it probably wouldn't need much extra rigidity to make it significantly more robust!

[bcg]

Interesting, thanks for the tip... I have a couple boards where the connector is off already, but I can solder the connector back to the two mechanical pads and try the reinforcement as you suggested to test out the strength. 

On the plus side even if the connector breaks off these are still really useful... I presume they can be programmed over serial, so I'm planning to play around with using one to drive Adafruit's new bluetooth HID device when they have them back in stock:  http://www.adafruit.com/products/1535

[jorgenslee]

For sure, you can definitely use the diagram for anything.  I put that together late at night and haven't tried the LED or AUX pins so its possible some could be labeled wrong, but I did double check the schematic so I think its ok.  I am attaching the layered GIMP file of that image in case you want to change anything

I agree about the micro connector... its really bad too because I know I've seen them with 4 mechanical solder points, definitely a design flaw to use this one on this board.

In case anyone comes across this thread and is wondering how to program this board.  After you plug it in to USB, it may not jump to the bootloader, even if there is no sketch loaded.  You might need to take a piece of wire to short the RESET and GRND pins and then "double tap" it.  Once you do that it switches to bootloader mode for 8 seconds and you can run avrdude or whatever to load your program (on Linux for some reason I have to sudo in order for this to work):

Code: [Select]

sudo avrdude -pm32u4 -cavr109 -Uflash:w:Soarer_at2usb_v1.12_atmega32u4.hex -P/dev/ttyACM0
I found the device name (/dev/ttyACM0) by using

Code: [Select]

dmesg | grep tty after plugging in the board and looking at the last entry.

On Windows you can try this:

Code: [Select]

format c:
j/k... don't do that... however replace /dev/ttyACM0 with something like com9, or whatever is shown as "Arduino Leonardo Bootloader" in device manager.

HTH

Sorry for necroing this thread but I would like to add something on to this. I've spent hours trying to find the device name of Pro Micro on my mac but to no avail using dmemsg and the system profile, and also there is no COM8. After some searching, I found and use this:

Code: [Select]

ls /dev/cu.*
Run that during bootloader mode, and after 8 seconds.
When in bootloader this is the list:
/dev/cu.Bluetooth-Incoming-Port   /dev/cu.Bluetooth-Modem
/dev/cu.usbmodem1441
After 8 seconds:
/dev/cu.Bluetooth-Incoming-Port   /dev/cu.Bluetooth-Modem

So now, you are sure that /dev/cu.usbmodem1441 is the device name and use it in flashing.

Code: [Select]

sudo avrdude -patmega32u4 -cavr109 -P/dev/ttyACM0 -Uflash:w:Hexfile.hex
Note: you only have 8 seconds to initiate the flashing before it returns to regular mode. Continually shorting the RESET and GND would not work.