OpenServo.com

[ginge]

Hi all,

I was just working with the OpenServos in a snake application, and I have come to the conclusion that the bootloader needs changing.

On powerup the bootloader will stay active for 3 seconds at 0xFF before moving on to loading OpenServo. This has proved to be a hinderance, and and looking for ideas on how to remove the bootup delay.

Ideas so far:
1) Use the INTn interrupt pin to move into bootloader when power is applied. This could be something as simple as pulling it low when we need to update the firmware.

Good points:
* We skip the bootloader unless we really want to go into it.
* Nice and simple

Bad Points:
* You can't reboot a servo remotely and update the firmware with the existing cable harnesses.
* You would need a cable to each servo' s INTn pin for more control, or another cable entirely.

2) Reduce the bootloader time to 1s and require that firmware updates are done quickly.

Good Points:
* Would not need to change OS firmware much

Bad Points:
* still a delay
* Would need to rewrite the software to poll all the time for the device and flash immediately


Your thoughts are welcome
_________________
http://www.headfuzz.co.uk/
http://www.robotfuzz.co.uk/

[jharvey]

I recently read an article about the use of NXP's ARM based chips the LPC series. These chips have some interesting boot loader things happening, so I thought I mentioned them here. When you get it, and plug it in via usb, it registers as a mass storage device. You then browse to it and find a web page. Open this page, and it contains the compiler, ect. No software to install. My understanding is that when it power on via USB, it goes into a special boot loader, that maps it's memory such that you can access it via fat32. So after you compile your hex file, you simply upload it to the mass storage device and your done. When you reboot it normal, it runs the firmware you just uploaded.

http://mbed.co.uk/beta

I swear I've seen that micro-controller somewhere as a different part number. But can't seem to find it now, so I guess that link is the best reference I have.

[ginge]

Interesting.

I actually have an OpenServo that runs a USB based bootloader. it doesn't quite work as your posted chip but does allow USB upload of the firmware.

It required extensive mods of OpenServo PCB and a different oscillator.

Regardless, not sure that it is a clean enough solution for me as it requires more special USB->openservo cables.

Back to the drawing board I guess.
_________________
http://www.headfuzz.co.uk/
http://www.robotfuzz.co.uk/