TNERA

Drone pour crottes de chien

Here is a video of a guy who has built a drone to collect dog poop from his grass lawn.  

He speaks very 'American', but there is a transcript available to translate.

That is an innovative method for opening and closing the 'scoop'.

Hi Sharklove,

I use the PCA9685 for many projects.  Here are a couple of thoughts. 

Yes, the LED on the board lights up when the PCA9685 is receiving power/ground for the logic (not ther servo power).  This means that it is receiving the 5V and gnd from your Arduino.
Your wiring for the PCA9685 looks correct. The SCL and SDA are connected correctly.

The one thing I can not verify in the pictures are the connectors and wires.  Be sure they are tightly connected.  Also, perhaps try different jumpers? The ones used may be defective or loose.

given that the issue is the I2C detection, i would focus on those connections.

I have not encountered this problem in my experience. One suggestion from other sources, suggests slowing down the I2C timing since your Arduino board is relativitly new. This can be done with:

In your setup() of your scanning code.

Wire.setClock(100000);

good luck!

Kudos! to you.  Thanks for putting the work and research in and making it for the community!

congrats to the team!

Speaking of quadruped gaits...

I believe we are entering a the next generation of Quadruped movement mechanics. The latest quadrupeds no longer rely on biomimicry for their gaits. With advancements such as stronger servos, lighter batteries, and more robust materials, we are witnessing new dynamics and an expansion in potential applications. Consequently, traditional animal gaits may no longer serve as the best training examples.

(warning: video contains scenes of violence against robots)

I believe this will also apply to humanoid robots. Eventually, robots should not be constrained by the limitations of the human form. I think this is shown well by the new electric 'atlas' from boston dynamics. Where the robot spins around and inside out on multiple 360° joints.

ah ha!  the Pronk - as defined by the AI - Perplexity.ai

Hi pmdd, (I'm just catching up on the thread!)

I love what you have done with Jagbot!!  the moving head for the distance sensor is fantastic. the movement is very Cat like!

Adding 'compliance' into the leg help store the energy for more advanced gates. This can be done with springs and dampers. It can also be added into the leg with bends, if you are using 3D printed parts.

To me - (and I am still lagging behind my peers on this forum) - Trying to remove the 'shuffling' of the feet on the floor would be important for any gait improvement.  Like Oracids test above for center of gravity. I am think how could I provide some balance by emulating the up down 'pogo-stick' leg motion we saw in early Boston Dynamics and Anymal quadrupeds.

Other Gait challenges that might be interesting is the "Pronk"!  or even a frog leap. 

Thanks Sandro, Oracid, 

 It does work! the PCA9685 board did not explode, and it was able to quickly react with all the additional power.  The connector is a little problematic, as with the new power source it 'chatters' probably due to poor grounding.

For testing, I using caution, making short tests, and then feeling the wires and connections for heat.  Smell also works!
 

I am not satisfied for long term use, for that using a better shield or making a better connection will be necessary.

Oh, can someone please make a GIF of your eyebrows at 1:12!  

awesome, I like using practical everyday materials to make robots.

I have used many times MG995 or MG996 and SG90 with 7.4V (2S) Lipo battery with no issue.

Thanks Oracid, that gives me the confidence that I will do no worse, than to burn them up!  

I will charge up and try it this weekend!  seriously, it is good to know that it is possible.  And I am guessing from previous conversation that putting any voltage reducer would be counter productive.

I find it interesting, as my last robot (the one that followed your 5bar design), really had the same issue.  I got it all the way up to the same point here, where the servos are just under powered.  This robot is much lighter and with in the capability of the servos.  I just need to add some more juice!

Wow, I am impressed.

points are points, but you guys were potting the plants in the buckets, while others were throwing the plants around!

Yes, a few points here and there on strategy and you all are going to be great contenders. 

Thanks for sharing the link, its really interesting to see the different strategies. 

All the best on your run up to the French Cup!

Entrainement intensif de jour comme de nuit, avec des séances d'agilité avec un leurre  et des poussées de poids avec une pile de livre de 3kg dont "Le python pour les nuls". C'est la seule façon de se préparer contre des champions , sur un match on ne sait jamais...

You need a Hockey Stick to push it around like at Boston Dynamics! 

all the best in competition!

Yes, Happy Easter!

Yes, MG995 is not ideal, but it is what I have.

Here is an updated picture that shows the motion & restriction of the right servo arm, as well as how it translates to the knee.  It is in orange and in the code/diagram theta2 is this knee/servo. What I see by drawing this, is that I only need to take the 'supplement angle' from beta (180-beta), and that should be the correct angle for the servo.  With additional protection restrictions to keep it between min-max.

the black bar is a push rod or cam(?). it runs parallel to the hip/upper leg. it push/pulls the knee at the same rate.  It forms a parallelogram with the upper leg. The motion of the right servo arm is independent from the hip servo, that upper triangle the bar is connected to is 'free' of the hip servo, but rotates on the hip servo axis.

Here is a short video of the non-IK version moving up down. It has 370g of weight on it.

https://www.youtube....rts/_2CwU8cZ-0Q

Hi, I barely have enough experience, that I doubt I could be dangerous...  . Most of my experience was telling engineers to get it done.

Check your connection methods.  I do believe Modbus RTU is a serial protocol, and would not support any IP addresses for communications. Typically it would be RS485 or RS232.

Don't confuse it with ModBus TCP which would be caried over an addressable network.

Hostely, to debug, I would post your question to a good LLM like ChatGPT 4.0.  This might help you down the path to discovery.

Good Luck!

As a follow up to this thread with recent news.

The Agtech startup Small Robot Company failed to raise new funding and was forced to shutdown. The company is in the UK and has previously were able to raise 13m in 6 rounds. They had 50 staff. Perhaps this was some indication of how hard it is to raise funds currently due to high interest rates.  or just that the market is difficult, as stated in this article.

From The Robot Report:

Agtech is a competitive market

Several global startups are competing in this market for smaller format agtech mobile robots. These autonomous mobile robots are designed for smaller farms, and especially for high-value crops. These companies include Burro, farm-ng, Naio Technologies, and SwarmFarm. farm-ng recently closed a $10M series A, and Burro recently announced the launch of its newest model, the Burro Grande.

This news comes on the heels of other recent bad news for some robot companies in January, including the RoboTire bankruptcy, the termination of Amazon’s acquisition of iRobot, and layoffs at Locus Robotics, Vecna Robotics and other companies.

Here is the full article: https://www.therobot...-shutting-down/