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I have built several boxes using a Coridium Pro Plus or Super Pro board. A point of difficulty has always been when I need to reprogram the board. It's not too bad, if I am in the development stage, but once the unit is in situ, it means nearly complete disassembly.

I would like to add a connector to the end panel of the box, and use a plugin cable that connects at the other end to a FTDI dongle. That FTDI dongle could be a stand alone unit or housed in another small box. The USB cable would plug into the FTDI dongle. The remote unit would also house a toggle switch, that supplies the ground connection to the programming pin on the Coridium board.

A panel mount Ethernet connector and a common Ethernet cable should do the job.

Has anyone done anything along this line?

This is quite easy in BASIC, your program only has to END and it is ready to download a new program. The BASIC firmware has a bootloader that reads a modified Intel hex file and programs the Flash. You can use BASICtools to create a new program or the program link included below to load a pre-compiled BASIC program.

http://www.coridium.us/files/BASICloaders.zip

You can do this a number of ways in C. It mostly depends on how you want to accomplish the download. If you run 5 pins out (the serial lines and 2 controls and GND), you can do a normal ISP download. If you want to just run 2 out, then you will have to write a bootloader or call the ISP from C (which can be launched with an IAP call).

I have decided to use mating DB9 connectors. I won't need a cable. I'll plug the programming box into the host. I can also eliminate the toggle switch, if I just ground the Boot pin in the programmer.

I built it, and it works. I included a toggle switch to short the Load pin on the Super Pro board to ground. I might need to open that connection to reset the board, or for any PRINTF statements in the code. Here is the pinout that I used on the DB9 connectors.

1 - 5 Volts
2 - RXD
3 - TXD
4 - DTR
5 - GND
6 - GND (for LOAD pin)
7 - LOAD (Boot)
8 - CTS
9 - unused

The USB to serial I/F that I used is a CP2104 USB-to-Serial Adapter Carrier. It has a DTR pin available. I didn't jumper DTR to RTS, I just wired the DB9-4 pin directly to the DTR pin, and bypassed RTS. I used a separate Ground for the LOAD pin, because it made my wiring of the toggle switch easier.

I intend to use this device as a direct plug-in to my Coridium based controller. I could also use a DB9 straight cable, or by swapping TX & RX pins, I could use a Null Modem Cable, since I kept the RS232 pinout for TX, & RX.