You can see that not all my soldered joints look good, and certainly I'm not proud of them, but they work. I find the best way to hold the header pins at the right angle for soldering is to insert them in a breadboard and then mount the board on them, see my photos.
* Without a little soldering work these boards are useless. In my view they are a better introduction to Arduino programming than the Uno precisely because they can be mounted on a breadboard, and getting three for nine quid is pretty awesome too. * These are excellent value boards that give you small and breadboard-friendly (when you've soldered the header pins) equivalents of the Arduino Uno. I downloaded and installed CH341SER_MAC.zip note that even though in System Preferences/Security & Privacy I had selected to allow apps from App Store and identified developers it was still necessary to specifically authorise installation of the driver from (chip maker) Jiangsu Qinheng Co. It did not have a driver for the CH340 and thus could not recognise the Nano board as connected.
If you don't have a driver installed then the CH340 will not show under Ports and the Nano will be invisible to the Arduino IDE and in fact to the entire computer system do note that an invisible board can also be caused by a rogue USB lead as stated above.* The Arduino IDE, either the app or the web editor, will flag up if you haven't selected the correct board selected under Tools > Board, but once you've sorted that everything is exactly the same as working with the Uno.MacOS* My Mac runs High Sierra 10.13.3. I attach a screenshot showing where the CH340 can be found under Ports in Control Panel-System/Security-System/Device Manager.
There was actually no need for that on my Windows 10 laptop because it installed a CH340 driver automatically, I cannot speak for other versions of Windows. Fortunately a desperate rummage turned up a USB-A to USB-Mini lead wired for data also, and then I was in business.* On the box there is a legend to the effect that a driver for the CH340 serial-to-USB chip must be downloaded. With the first two USB-A to USB-Mini leads I tried my computer didn't recognise anything connected to the USB port, apparently those had been supplied as charging leads for things such as lanterns and cameras and were wired for power only. The USB socket is Mini, not the much more common Micro, and that caused me some perplexity. The bootloader has been fine for me with Arduino Nano as the selected board in the Arduino IDE and ATmega328P as the selected processor.* No USB lead is supplied. This is handy because as soon as you power them you see the LED flashing and know you've got a working board. The ICSP pins are easily retro-fitted if the need arises.* The boards were supplied with a bootloader installed and the Blink program in memory.
Some of my Nano boards have the ICSP pins fitted, some don't I've not yet needed to flash a bootloader.
The pin spacing is wide enough that accidentally bridging two pins seems most unlikely, so even if you've never soldered before I would encourage you to give it a go.* The separate block of six pins is for ICSP (In Circuit Serial Programming) and unless you intend to replace the bootloader you don't have to fit it.
In my view they are a better introduction to Arduino programming than the Uno precisely because they can be mounted on a breadboard, and getting three for nine quid is pretty awesome too.* Without a little soldering work these boards are useless. Reviewed in the United Kingdom on 14 February 2018