Is it possible to use the T-Hex 4DOF legs with the 3-R chassis as used for the AH3-R Hexapod?
And if so is there much advantage to doing this?
The 4DOF legs do seem more versatile but I want a symmetrical bot.
Rob
Yes it is possible: see my thread: viewtopic.php?f=8&t=7687&hilit=THr_4
Advantages. Look cool… 8)
Kurt
Thanks for that, it looks great.
One more question, I will probably have my own ARM processor board (Arduino Due compatible hopefully), I gather that I can interface that with the SSC-32 using a TTL serial link and either ASCII or binary commands. Correct?
Rob
Kurt’s hex is actually using a 3DOF t-hex leg, but there is nothing preventing you from using the 4DOF legs. Our current guides for the 4DOF t-hex use the Atom Pro. I’m not sure if the codes been done in arduino format. The SSC-32 does support ascii and binary at 115.2k.
Jim, actually it is 4DOF 
Yes the BotBoardDuino code (as well as my multiple version) does support 4DOF. The picture above shows it with a Seeedstudio mega with an earlier prototype shield.
Wish I had an Arduino DUE to try it out on, but I don’t think it is released yet, except there are rummers that a few of them are out to some select people… Wish one of them was me 
Kurt
Good, then when (if) the Due arrives it will probably port across without too much trouble.
Correct, there was supposed to be a big announcement “after Easter”. I got sick of waiting and designed my own board 
Doh! I forgot that first video was with mixed 3DOF and 4DOF legs… lol 
Yep should not be hard. I have it running as well on the Chipkits (UNO32/Max32), which are Pic32 based and their IDE (MPIDE) is based off of the Arduino.
Yep I know that feeling, one rummer I saw recently on the web is July… So how close is your board design to what we think is the Due?
Kurt
Physically nothing like it, I wanted to go smaller (it’s 2.2" sq), provide for debugging support, addressable “shields”, external memory, control of a power (5A up to 30V) for an external device, system power shutdown/wakeup etc and I’m sure the Due will be dumbed down so I decided to go my own way. For better or worse
Apart from the fact that I won’t be able to use shields I don’t think it matters, after all there are many Arduinos that don’t (Teensy, Pro mini etc).
What I hope to have is the same processor and therefore all the libraries and tool chain. When they first released details they said the Due would use the SAM3U4E, they have since said that they may be using a different processor but if you analyse the SAM3 range the 4E just seems the most appropriate, for example it’s the only one with 5 serial ports and USB. So I think that was a smoke screen to throw off the clone makers.
Working on that assumption I decided to finish the design with a SAM3U4E, brief feature list as follows.
• SAM3U4E 96MHz ARM Cortex-M3 processor.
• A 102-pin backplane with up to 8 addressable daughter boards and provision for memory expansion and/or fast IO.
• Debugging support with JTAG, two dedicated debug pins and an on-board 7-segment LED.
• Software control of power to the entire system and various subsystems.
• Provision for up to 32Mb of external SRAM.
• Battery backup for external SRAM (if fitted) and the SAM3U’s internal RTC/RTT/backup registers.
• High-speed 4-bit microSD interface.
• Serial ports, five USART/UARTs, two I2C and one SPI.
• I2S interface for CODECs, DACs etc.
• Up to 86 IO signals, including 16 analog inputs and 10 PWM.
The PCB layout is finished, I’ve been sitting on it a bit waiting for the Due but TBH I doubt I could stand a redesign if I’m wrong about the processor so I may just go ahead anyway.
http://www.robgray.com/temp/Quub-PCB.jpg
Rob
Looks nice. Yep I agree about not necessarily needing shield support. Still hoping they will release their board soon so we can all see what is really on it.
Kurt
Wow, board is looking good. As I always try to do with mine, do a sort of a fit check with interface cables, you don’t want any of the connector stubs hitting the board…
Did you use Altium?
I think my connections are free, after all there’s really just the two main socket strips and with the 3D modelling these days it’s pretty easy to see that sort of thing.
Yep.
I’m sitting on the thing for the moment, hoping (against hope?) that the Due will come out soon so I can see how compatible I will be.
Also as I’ve recently got interested in robotics I’m wondering if I should make any changes to more align it with use as a robot brain. Probably not as stuff can be added as daughter boards and I don’t want it to be **just **a robot brain.
Rob
You can certainly pull out some of the serial pins for future “add-ons.” It’s always good to have a combination:
- SPI
- I2C
- CAN (for the really low rate, robust serial)
- RS-232/422
- USB (although this is not very ideal for real-time applications)
The problem with a “Do-it-all” board is not everyone would want to buy a “Do-it-all.” The problem with having a “Do only one thing” board is that another crowd would want it to do more 
It’s like the BAP+SSC-32 crowd vs. ARC-32.
I’m a hybrid guy myself. I love the SSC-32 for what it does, so it shows up on both my bots. I dislike controlling the servo with the ARC-32 because space isn’t an issue. I think if space and payload was an issue, I would be using the ARC-32 as a servo driver myself. I’m going to experiment with both configurations since I think my ignorance is due to lack of understanding of how hservo works at the moment
Arduino have just tweeted that they will be using a SAM3X, so I have to decide if a redesign is worth it. Interestingly the 3X has CAN, it also has twice the memory, a DAC, EMAC and a TRNG (true random number generator) all of which makes it a pretty tempting chip to use.
OTOH I don’t think it is available despite info being released years ago. Maybe a U3E4 in the hand is better than a 3X8E in the bush.
Yes the old modular vs all-in-one debate, I tend to favour the modular approach but there are many design and cost implications for both paths. This board is essentially modular but I thought it made sense to add a few features that would otherwise require an entire stacking daughter board. I think I have a good balance.
I’m thinking of doing a intelligent IO board that could handle say 32 servos or various IO combinations. This IO board could also handle sensors and as the daughter boards are addressable you could use up to 8 of them for no end of servo/sensor combinations.
Rob