Looks good! I see you have mounted the NyBoard directly to the Nybble. I tried to do this but could not then connect the wires from the servos (hence why I used the standoffs). Could you show a side photo close up of "under" the NyBoard where these wires attach to the NyBoard to show how you made those connections? Thanks in advance.

All fixed! Nice rig you've got there!

I use standoffs to mount the NyBoard well above the Nybble frame. See this post and the picture below. This makes Nybble ready to receive the Pi (a zero in my case) plus makes it easier to connect the servo wires. Hope that helps!

Great point!

Great discussion on an important topic. Just wanted to cross-link to a comment that @Rongzhong Li posted here about how Tower Pro servos (in the original Nybble that I have) are commonly cloned and counterfeited so it is difficult to get genuine Tower Pro servo.

You're welcome and let me know if this fixes the behavior that you have observed. 😎

Good eye! Glad to hear you have found a better servo manufacturer. Who makes the new ones? Can you provide some specs and/or a weblink. Also, will you be updating your servo comparison Google sheet? I got my Nybble while you were still in Pittsburgh in 2019. I worked on it over my Christmas holiday (only built the head!) and then got busy with other things. I returned to Nybble in May 2020. I completed the hardware and have been studying your OpenCat code framework ever since. I love this platform (hardware and software) - you and the Petoi team have done a great job! Thanks for your kind comments! I look forward to sharing and learning with this great robotics community. Cheers! 😎

That would be great and I'd be happy to test it with vMicro. Cheers!

Sounds great! What will be the power requirements compared to the NyBoard v0_2? Will it still be possible to connect this board to a Raspberry Pi or is it so powerful that this will not be necessary? It looks like it has the IR receiver mounted directly on the board rather than on a flexible "stalk" like on the v0_2 board. Does this mean that the board should be mounted on Nybble in the "above" position (like you would with the current v0_2 board if you were going to add a Pi)? I use Visual Studio with the vMicro extension. Have you tested the board with that IDE? Well done Len! I can't wait! 😎

Was wondering what ly and vt were. Thanks!

I am amazed at how much reducing the size of the IRremote library can save us in program memory. I just turned off (set to 0) all of the supported IR protocol #defines (in Arduino\libraries\IRremote\IRremote.h) EXCEPT for the one that is needed (#define DECODE_NEC 1) and found that we save 3282 bytes (ca. 10%) of program memory! 😻 Nybble likes! Thanks again for that sweet tip!!! 😎

Thanks for that info Rz!

If you want to temporarily gain some program memory space, you can set a compile directive to not use the gyros (see below). Of course doing so effectively puts the Nybble into turbo mode since the servos get more cpu cycles. If you want to use this trick a lot, you would need to throttle back the servos by e.g.: [1] using more steps as is done in the behavior() function with speedRatio or [2] using the same number of steps but with a pause after each (new code would be needed) or [3] reduce the servo voltage (hardware fix). Of these, I am planning to use approach [1]. Update: 2020-07-05 Since the behavior() function only works for poses and the need above is to throttle back the servos in gaits, approach [1] will currently not work for this purpose. I think the simplest approach at present is to turn on the compile directive "#define SKIP 1" in Nybble.ino. See @Rongzhong Li's comment here. Of course, this doesn't provide fine speed control nor can you change the speed in real time (though the latter could be handled with some code changes, e.g. approach [2] above). BTW, changing SKIP to higher integer values will further slow the gait speed which can be handy for study of each frame in a gait! Code Snip: #ifdef USE_GYROS // set our DMP Ready flag so the main loop() function knows it's okay to use it PTLF("DMP ready!"); dmpReady = true; //TS dmpReady = false will disable the checkBodyMotion() function so the gyros will not be used and speed increases to turbo. Program memory consumption drops to 89% in my case. #endif

I am not a fan of the Arduino IDE so II use Visual Studio Community 2017 with the Visual Micro extension (see here https://www.visualmicro.com/ for info and here https://marketplace.visualstudio.com/items?itemName=VisualMicro.ArduinoIDEforVisualStudio to download from the VS Marketplace). Visual Micro manages the compiling for the CPU in the Arduino (and any compatible like the NyBoard). You still need to install the Arduino IDE since vMicro uses it "behind the scenes" but you don't directly use the Arduino IDE to write and debug code. Visual Micro has a 90 day trial period. After that you need to purchase either an annual license ($19) or a perpetual license ($100). You get the full power of the Visual Studio IDE so I think it is worth the $19/yr. Note that Visual Micro works best if you only have a single .ino file in the VS project so I have a Nybble project and a WriteInstinct project. Hope that helps!

If we don't mind bypassing the gyro, we can make Nybble go quite fast. I changed the code (see below) so that the turbo command toggles access to the checkMotion() function since it is nice to do fast movements for longer than the default 4 cycles and to have control over how long the kitten stays in turbo. Tap the IR remote turbo button to go fast and then tap it again to go normal. Of course, turbo uses the battery power more quickly. It is really amazing how large a fraction of the CPU time the checkMotion() function requires! Code Snip: else if (!strcmp(newCmd, "tb")) //TS command = turbo. It toggles the gyro to give more cpu cycles to the servos and so moves the cat faster. { if (checkGyro) //TS If gyro checking is on then we need to turn it off { //countDown = 4; //TS This was the default. Can set value higher now because I added turbo toggle code checkGyro = false; countDown = 100; //TS enable longer much countdown } else if (!checkGyro) //TS If gyro checking is off, we need to turn it on { checkGyro = true; countDown = 0; //TS disable longer countdown } }

@Rongzhong Li Sure thing! These pictures below show the difficulty presented by the green power connector with power wires (hits the wood support) and the top PWM pins (inaccessible when mounting the NyBoard on top in the "with Pi" configuration). Thus, please consider alternative ways to mount the NyBoard on top of the wood support (like using stand-offs). Top View of NyBoard on Nybble: Difficulty aligning NyBoard with holes of "NyBoard with Pi" support. This shows the problem of the green power connector. I have notched the support but apparently not enough and IMO, such notching should not be necessary. 02-01 Top View of NyBoard on Nybble.jpg Below Side View of NyBoard on Nybble: This shows how the top PWM pin CANNOT be accessed.. 02-03 Below Side View of NyBoard on Nybble.jpg

I found it very difficult to mount the board on top (NyBoard plus Pi style) and still get all the wires tucked and routed under the NyBoard (i.e. in the "belly" of Nybble). Please consider alternatives that would make this easier (perhaps stand-offs that raise the NyBoard up?)

How about supporting more RAM as in an Arduino Mega?

I'd like to see 5 touch sensors (e.g. one for each paw plus one on the muzzle)

Thanks for that additional insight. Also the 3D printing idea is a good one except, sadly, I don't have a 3D printer nor do I have access to one.