dutky's Journal: Hacker's Handheld, part VI

I've got the LCD and SBC that I ordered. There was a slight delay on the SBC, due to a miscommunication between the reseller, Microcross, and Cogent, but the reseller was very nice, once I infromed them of the problem, and overnighted the package to me at no extra charge.

I might have brought some of this on myself, since I changed my order between the time I talked with the folks at Cogent and when I placed the order with Microcross: the Cogent folks were expecting an order for a CSB336 and I orderd the CSB335 instead. I went with the 335 because it was cheaper and slower (I want to see just what the worst case would be) and lacked some of the peripherals I need (I want to get my hands dirty with some custom electronics. This is, at least partly, a hobby, and what fun is a hobby unless you get to build stuff?). I'll go back and get the 336 or 337 in a few months, when I'm comfortable with the development process.

Speaking of the development process: I've only played around with the board for a few hours, but it's pretty impressive. It comes with a JTAG port but you can do everything via the serial or ethernet ports and the built-in micromonitor (which is good, since I don't have a JTAG interface cable for my Linux box). The micromonitor is pretty nice, at least as good as the boot monitor on my old PDP-11/44. You can set and examine memory, download stuff via xmodem or tftp, run executables either from memory or from on-board FlashRAM, and save things into the on-board FlashRAM as if it were a disk drive. The only time I might need JTAG is if I want to update the micromonitor: you can update the micromonitor just fine over serial or ethernet, but if you screw up, you need JTAG to recover!

I also bought the CSB300 breakout board. The boards were shipped together, preassembled into a single unit. The breakout board has two 9-pin D-shell serial ports, two 9-pin D-shell CAN ports, a reset button, three user defined sense switches, two user defined LEDs, an ethernet port w/ activity LEDs, a USB device port (not supported by the CSB335) and a 5V power jack. Along with the two boards, the shipment included an ethernet cable, a null-modem cable, a 5 volt 2 Amp external power supply and a print-out of the CSB335 Hardware Reference Manual (available for download as a PDF from the Cogent website). If I'd had things together on my end, I would have been all set to start development (I didn't have minicom, or the ARM cross-compiler, installed on my Linux box).

My next tasks are, probably, to get Linux booting on the SBC, and then to build an adapter from the SBC's LCD interface pins to the cable on my LCD. Beyond that, I need to build boards to 1) poll the touchscreen and present the data to the SBC (I have found an article that describes how to do this with a PIC microcontroller, as well as another article that presents a pretty good overview of resistive touchscreens), 2) adds USB host and device controllers to the system via the memory/system bus and 3) add an IDE interface to the system bus (there are some reasonable references for this on the net). In the short term, however, I'm just going to play around with the micromonitor and try to get the ARM cross-compiler working.