Zoid wrote:
Mark (or others), has this ISP pinout been confirmed yet?
Mark (or others), has this ISP pinout been confirmed yet?
Yes. We definitely use the SPI interface + reset to program and hack our CM5, and incidentally the AX-12 board too. Just use a multimeter to buzz the J5 connector back to the MCU if you want to double-check the pinout.
pepperm wrote:
Maybe the Bootloaded is pretty standard and could be replaced by something in the public domain. Bootloaders are pretty simple, they have to be because they only have a small amount of space to live in so a public domain one could be modified if meeds be.
Matt wrote a Bioloid-bus-compatible bootloader in a few days. We're probably going to release this as binary-only but to install it you'd need to chip-erase the CM5. This isn't hard and can be done with a parallel port and some soldering.
Alternatively just leave the Robotis bootloader alone. It's not THAT broken...
Miamicanes wrote:
I suspect the fact that the Mega128 is SMD-only has a bit to do with it. The pins on the "big" one are .8mm apart. The pins on the "small" one are .5mm apart. That's pretty dense. Even with a little experience and the right tools, those are hard chips to solder with hot air, and just about impossible to solder with a "normal" iron. Now... removing bridges isn't as hard as it sounds (with a solder wick, it's actually pretty easy to do), but finding them in the first place can be a major pain (problem #1 -- the probes on most multimeters are too big and bulky to easily test adjacent pins for shorts).
I hand soldered the Mega 164 SMD (0.8mm pitch) and the line driver (0.5mm pitch) we're using on the PSX board. With a steady hand, a good light and a decent wick it's actually quite easy. A magnifying glass is also helpful but not actually necessary.
Getting the bootloader firmware off the original chip and onto the new one could be a problem, too, if Robotis set the protection fuse when they burned them (AVRs have a fusebit that enables you to protect them from casual ripping). It would be pretty stupid if they did, since their firmware would be almost completely useless without Robotis's own servos anyway, but never underestimate the grief and mischief paranoid lawyers can cause when they start influencing otherwise-sane members of upper management...)
We managed to get the Robotis bootloader image off the CM5 and servos in about 5 minutes. They HAVE set the lock bits to prevent reading of the image but they didn't put any sane protection in their own bootloader. You can ask the bootloader to read the flash and then dump it to disk. We've got backups of all the firmwares and bootloaders now, just in case something goes horribly wrong. As I put in another thread I'm NOT prepared to distribute these. I'm happy to help with how it's done but I'm not distributing someone elses intellectual property.
djmartins wrote:
Which makes me wonder why no one is working on a Mega128 replacement board that uses essentially the same pinout as the CM5, but brings out more of the IO pins for other uses.
Couldn't one then use it exactly like a CM5 if one wanted to with all the Robotis supplied software?
We're working on a drop-in replacement for the CM5. Details are still sketchy (still on the drawing board) but it likely to be a 32-bit system capable of running Linux, we're targeting 150MHz and pin-for-pin/screw-for-screw compatibility with the CM5 so that it can go into the same chest cavity.
For our uses we're not planning to run Linux at all (too much overhead for too little gain) but for those wishing to have more intuitive scripting languages (e.g. python) and aren't concerned about 100Hz sampling rates it's likely to be a good solution. More info may be coming, ETA is probably about a year.
Statistics: Posted by StuartL — Tue Dec 16, 2008 10:24 pm
]]>