Open Panzer
Developer's Forum => Scout Dev => Topic started by: LukeZ on December 06, 2016, 04:02:49 PM
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The Scout ESC in its current state is fully functional with the TCB, general RC radios, and other microcontrollers. There are however always things that can be added, here is a list:
- Add serial commands 6-13 and 16-17 compatible with Sabertooth protocol (low resolution commands, mixed-mode driving, ramping, and adjustable deadband): See this document for the Sabertooth reference: Sabertooth 2x12 Reference (https://www.dimensionengineering.com/datasheets/Sabertooth2x12.pdf). These commands would not be used by the TCB and aren't useful for the Open Panzer project specifically, but could be used in robotics applications.
- Characterize empirically the board heat profile at various currents, and improve the fan control algorithm: presently the board will engage the fan when onboard temperature measurement reaches 40*C (~100*F) and the fan will reach full speed by 70*C (~160*F). This range was selected somewhat arbitrarily and there is nothing intelligent about it. In all honesty, during our testing on 1/16 scale models we had a hard time drawing enough current to even get the fan to come on, implying the entire fan functionality is not perhaps really needed in most applications. A temperature-vs-current graph would be good information to have if someone can come up with a suitable current-draw test load.
- Test various fans and decide on a specific model: As mentioned before the fan rarely if ever comes on with the typical currents drawn by a 1/16th scale tank, so I've not done a lot of testing to find the ideal fan. The connector on the board is plug-and-play with standard 2-pin 40mm PC case fans. If someone does a temperature-to-current test it would be interesting to see how effective a fan is at cooling.
- Design a case: a case (3D printed or otherwise) would be nice, perhaps one with a fan mount.
As a reminder, here is the GitHub page (https://github.com/OpenPanzerProject/Scout-ESC) for the Scout firmware. If you choose to add some code for #1 feel free to submit a pull request.
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I will take on the case job for the Scout. Is the current design the final form for now? If possible do you think we can add two M3 holes on the other side? I know the layout is very busy on that side, it isn't a biggie if we can't, just looking to get this case as low profile as possible. I'll post the STL files as well for any to mod or print in a separate thread.
Edit: On a separate note, the design will be standard fan size. I like 25mm myself, I dont think the board needs much more than that and 40mm may make the case too big. I'll look into this and maybe post two designs. In my testing I have found a 25mm is plenty enough in the hot Florida sun, but a larger fan never hurts, especially on the larger and heavier tanks starting to emerge.
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Erik, the final version is actually Rev 10 and I think the one you have is probably 8 or 9 (it should say on the bottom of the board). The Rev 10 files are on the Downloads page, the main difference is that it is slightly wider to make room for a 3-pin JST-PH serial plug instead of the 2-pin on the version you have.
If you don't have Eagle I can make up a dimensional diagram and post it soon. You can also always buy a bare board from OSH Park (https://oshpark.com/shared_projects/yxFCuWWM) and then you have the physical thing in your hands if that helps (it's about $24 shipped for three).
I've tried sticking screw holes on the far side several times but there's no good way to do it without significantly increasing the board size. Maybe it's worth doing, I don't know... with a case it would seem the extra screw holes might actually be less important than without a case.