Hi everyone ! I just come back from holidays and I have received my electronic boards \o/ (made on SeeedStudio)
I also received some cables and the new speakers. I hope I will have time this week to solder the boards.
There are some problems with the top Silkscreen (some letters are missing) but the tracks are good and the quality is also very good. I think the problem comes from the gerber export which gone wrong at some point…
Hey,
The Raspberry is finally installed ! I just bought the model B+ because it has 4 USB ports, and as I will need 2 for the Wifi and the Webcam, I needed 2 more for the keyboard and mousse for programming the PI 🙂
The model B+ has also 4 mounting holes, which is perfect pour the fixations and it consumes less than the previous model (around 150mA). However I will need to replace the USB and Ethernet connectors which don’t fit in the hood by pin row connectors 😉
I also mounted the mini USB of the STM32 on the top, which is much more easier for programming…
Now I can continue with the final step : The head
Hello 🙂
I finally finished the integration of the boards inside the body ! It took a little more time than I thought but I wanted the most reliable solution.
For the fixation I will use a carbon fiber support (which I will machine with my CNC). This support will also reinforce the body’s structure 😉 and so far, everything is fitting well inside so I hope it will be the same for the head…
However, I still have to integrate the Raspebby Pi, which will be placed above the STM32.
So, the next step is to put the Pi inside and then begin the head design.
Hey,
I spent the last week on the electronic design. I finished all the boards except the one for the Pi. All the schematics and PCBs are made on Altium Designer.
I also received all the components \o/ so now I can check a last time that all the footprints are correct.
The next step is to send the gerber files of the boards for manufacturing. I’m hesitating between 2 manufacturers : OSH Park and Seeed Studio PCB. I think I will go with OSH Park (previously Batch PCB) because they have a better quality even if they are a bit more expensive than Seeed Studio PCB.
Now I have the boards, I can continue the work on the integration of the boards into the robot and the design of the head.
Hello all,
I didn’t advanced much on the Solidworks Design because I need the size and shape of the PCBs I have to integrate…
Animabot will be composed of 5 PCBs in addition to the Raspberry Pi and the STM32 :
I’m using Altium Designer for the Electronic design, I know that it is a complicated software for the boards I have to do, but I am used to it (I used it previously with my first Hexapod and at my school). For the moment I’m spending a lot of time creating the components and footprints I have… so not very funny…
However, I will create the 4 others PCBs in the next few days to be able to put them into Animabot.
I also put an Infrared sensor on the front of the robot, so he will be able to avoid falling in the stairways or from a table 😉
Hello 🙂
I finally finished the legs \o/
Now the legs are done, I can concentrate on the integration of electronic boards inside the body and the design of the head which will integrate :
I also made a special shape for the DC IN connector and the 2 interrupters. I decided to use 2 interrupters in order to be able to disconnect completely the battery from all the electronic (safety reason) and the other is used to power ON the command (Pi and STM32F4)
I hope you like it 🙂
I reviewed the power distribution of the robot and the system of 2 batteries… and finally, I’m not satisfied… Having 2 batteries inside take more space, it’s not good for the weight balance and it’s more complicated for the electronic because I would have have to design a board with 2 chargers (LTC4008 and MCP73861) and 2 power monitors (LTC2945). It’s not that complicated but designing a charger board is not obvious and the Electromagnetic compatibility (EMC) would be a nightmare…
So I searched on the Internet for a new battery, and I found this one : Tenergy Li-Ion 18650 11.1V 7800mAh. I could have assembled the battery by myself by buying each element separately which is much more cheaper, but I have enough work to do… 😉
There are many benefits :
It looks like this once integrated :
I logically changed the charger and chosen a LTC4006 which fit perfectly to my application. Indeed, the LTC4008 doesn’t have a integrated termination charge like the 4006 and the use case of the robot (charging point of view) will be the same as a laptop, so I needed a charger compatible for this utilization.On the datasheet you can find a good application schema, which I have to modify to fit my expectations in order to handle the average 5-6A consumed by the robot…
However, I’m still keeping my precious switching regulators :
I replaced the PTN04050C by the PTN78060WAH (boost converter), as I won’t use the 3.7V Li-Po battery anymore.
Here is the new electrical architecture :
Hi there !
I finished the coxa articulation, this was a bit more complicated than expected, mostly for the shape design… I created a hole inside the part to be able to pass the cable inside, like this it will not be visible 😉 I didn’t had the time for running some stress tests on this part, so I will do it this week and update this post ^^
I still have to finish the leg. As you can see on the global view of Animabot, the legs are not fitting right on the femur : it is normal, and I will correct that this weekend !
Looks pretty good, no ?
This weekend I have been working on my Media Center with another Pi.
First I installed OpenElec, which is after some tests, much faster than Raspbmc. You can find here how to install it. Then I overclocked it a little to get Xbmc smoother (tutorial here). I choose the Medium overclocking configuration which runs perfectly well and is very stable on my Pi.
Concerning the integration, I wanted it hidden behind the Tv, but it had to look good (no cables everywhere…). I have looked for a long time for a proper case in aluminium but without success… So I finally decided to use an external hard drive case 3,5″‘. The internal dimensions are sufficient for installing the Pi and the cables. The case is also ventilated by may holes on the side panels, so the Pi will not get too hot inside.You can find it on amazon for 22 euros.
For powering all this I used a switch Mausberry Circuits to be able to power ON/OFF the Pi correctly. But the inconvenient is that you have to do it manually 😦
On others occasions, I noticed that the USB port on the Tv is ON when the Tv is ON and OFF when the Tv is in Standby (I have a Samsung UE55F6400). So I came up with the idea of replacing the original interrupter by a relay commanded by the USB port. I simply connected the coil to the 5V of the USB and put a diode (1N4007) to protect the USB Port. On the interrupter circuit I only added a small capacitor (4,7µF) for the relay bounces.
When I power ON the Tv, the Pi starts automatically and when I put the Tv in Standby, the relay goes OFF with the USB port and the script installed on the Pi send the shutdown request.
This works perfectly !!
Hi !
On the last few days I have been finishing the fixation of the servos in the body. I changed the fixing studs for stronger ones. I still have a lot of work to do inside, but first I want to finish the legs.
I have advanced in the femur part, I still don’t know if I will keep this design because the upper part is flat and I’m not sure it combines with the body shape… But however, the servos are fixed inside, the part is relatively compact, and the cables should fit… so it’s not so bad 😉
I also have temporally integrated this to the body, to see how it looks like and this gives also an idea of the size : Cool isn’t it ?
I think I will have to make the corners of the femur and the body a little bit rounder for the articulations movements… But I will see that with the articulations
The next step is to create the fixations between the body and the femur with a cable passage inside (tricky part…)
Hexapod Robot Animabot created by Emmanuel Sichet is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Animabot & Anim4Bot names created by Emmanuel Sichet are licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Anim4Bot 