.Net MF File transfer, is there a better way?

NETMF & Gadgeteer
1

My application generates many large-ish (several MByte) data files stored onto a SD card that I need to off load regularly. Unfortunately, my system is sealed inside a pressure housing so physical acess (like pulling the SD card and plugging it into a PC) is not really an option. I have 2 ways to do this now. 1) I have some code in my app that allows me to do XMODEM transfers using a slightly modified version of Iggmoe’s XMODEM library over a bluetooth dongle connected to one of the Raptor’s serial ports… 2) Download a program that makes the Raptor look like a mass storage device using GHI’s Mass Storage Class.

Both of these work but the Bluetooth way is slow (115 kbaud) and the MSC way is awkward since I need to put the Raptor in serial debug mode with a jumper connector that has to be plugged into a connector on the bulkhead of my pressure housing. Is there a better way?

It turns out I can get the bluetooth signal through my pressure housing just using the rubber ducky antenna on the bluetooth dongle insde the housing, no external antenna. I’m guessing I can get a WiFi connection at least over short range also using an antenna inside the pressure housing. I’m not a particularly experienced programmer so I don’t know how much is involved in getting a WiFi file transfer functionality up and running. Even if I get WiFi running, do I need some kind of FTP library? If so, is there a solid FTP library available that I can make work without too much effort or a detailed knowledge of networking?

Thanks - Gene

2

Hi, you could use Reinhard Ostermeier’s Ftp Server together with the WiFi RS21 Module. The max. Transmission Speed was reported to be 19KBytes/sec. What kind of Bluetooth dongle did you use and which transmission protocol?

3

If it’s just a couple files, you could make your own trivial protocol over TCP or UDP socket. No big deal. However, ~120kBps is just about the best result you can expect from Raptor.

4

I’ve been using a Sena SD1000 with pretty good success http://www.senaindustrial.com/products/industrial_bluetooth/sd1000.php .
The Bluetooth and serial port run at 110 kBaud and I get about half that for throughput using XMODEM (I think, I’ll have to check again). 120 kBps or even 19 kBytes/sec might not be a big enough improvement to justify the work,