I'm wondering if a small handheld device exists that can upload Arduino code via USB?
(Note this is not about installing the boot loader on an Atmel chip.)
Say I have a bunch of Arduino based devices in a room and they are in awkward locations and I need to load them all with new versions of my app software. Rather than walking around the room with a laptop and using the standard IDE I'd like a small black box device where I just plug in the USB cable, hit a button, and then disconnect the cable. Presumably the code would first be compiled on a PC and then the binaries transferred to the black box, maybe via SD card or USB.
Anyone seen such a device?
You might be able to use an android device, depends on the boards.
Not USB but there are many standalone ISP programmer around. But you will need ICSP access to your Arduinos. So if you can get access to the ICSP pins then this should be a good way to go.
Actually, gammon's standalone programmer does require a serial terminal access to select menu options. It could be modified to run completely standalone.
Here is another example of a completely standalone serial programmer with LCD screen. But this is not a USB programmer, it uses serial FTDI type connections.
You need something that can be a USB host, that also works with the bootloader program. That's why you'll need a PC if you are not programming via the ICSP header.
If a USB host shield is added to an arduino and programmed to do what Avrdude does to interact with the bootloader, then you could program via the USB connecter.
Android device, OTG USB adapter and Upload Sketch app. You can develop & compile on Android too.