Hi, this is Wayne again with a topic “Projects With Ryan Slaugh”.
In part, one of our robot redo, we took an old toy and started tearing it apart. First to see what we could use and what we didn’t need, utilizing the parts that we could use. We went through and found out what they needed to operate. What voltages and what currents from there we chose our parts, the uno, the motor shield and some other parts internal to the robot, including a raspberry pi, the raspberry pi, in this case being coupled with an ala mode from there, we did some initial placement and initial Design work and came up with this design for interconnect in this part 2, we’ll finish that design hook everything together and get this robot up and running. First, it’s good to review the design that we originally had here.
We can see how everything connects together and overall, throughout the project that didn’t change. What did change was the power. There was a lot of comments back and forth of why i chose to use a 7805 and a couple: nine volt batteries. The reason i use that and don’t just apply 12 volts to a 7805 is the fact that it’s a linear regulator and it’s highly inefficient, meaning that it’ll actually have to dissipate most of its drop in voltage from 12 volts down to 5 volts, which is 7 Volts in heat – and i didn’t really want a little heater inside the robot. Therefore the 7805 wasn’t the best choice.
However, the design that i had here wasn’t the best choice: either a helpful youtube commenter suggested using this a bec which is used in hobby electronics. This can take a high voltage input such as the 12 volts and even higher, and give you a 5 or 6 volt output, depending on the jumper setting. They handle a lot of current, so they will have no problem in running any part of the electronics and they are a switching regulator, meaning they’re far more efficient.
My first step is to connect everything up the way i need it. This is the power converters, the raspberry pi, the ala mode and the arduino with its motor shield connecting the motor shield also to the motors. I do this all on my table or lab bench, and i start playing with the software and the programming to make sure everything is talking correctly for power. I use my mobile prototyping kit to give me a solid 12 volts. Then i can see how everything works together. One of the first things is do is to put the ala mode into the raspberry pi.
First, you can place the micro sd card into the island mode. This will allow you to do some data logging or saving of actual program configs later then, you find the double row – header, that’s the gpio or general purpose. I o and the auto mode will actually plug right in to the top of it and it all fits very snugly inside the raspberry pi case.
That’S how you install the ala mode onto the pi in this article. I will not be able to go through the sd card setup or the initial setup of the raspberry pi. There are plenty other tutorials out there that can help you do this.
In fact, if you don’t have the book getting started with raspberry pi by richardson wallace, i would suggest that you do go and get one. It has a very good, step-by-step tutorial in getting you started, and it has a lot of chapters on how to use the raspberry, pi and all of the different features. He would make this video roughly three or four hours long. If i actually went through point for point everything that i did to set up my raspberry pi, my arduinos, but don’t despair in the links, there is a document that shows each step and what software was installed. Different applications were needed for use by the robot, so i installed each one of those. I first started out with an update for the for the raspberry pi.
Then i went to install apache php, the arduino software itself and the ala mode software. The ylm company that makes yellow mode has a great tutorial and that’s included in the links as well to get it up and going some very important bits of software. That you’ll use are ssh which will actually enable with the raspberry config file and that’s shown in the document and remote desktop. These allow you to actually remote into the raspberry pi when it’s in the robot body, because programming on that little three and a half inch screen will be difficult, even if you have the best device.
So you want to use those two things to enable you to talk directly, the raspberry pi, showing here i’m actually running the arduino software loading in the ala mode via the vnc connection. Once the software is to a stage where i can control things, i take the hardware and mount it to the body. I first do a placement and layout to see where things will fit. Then i start the actual wiring included in the video is a schematic showing all of my connections. Once i get finished up with the connections, i have kind of a wired mess. I leave everything long during the prototyping stage in order to be able to make changes.
If i need to i’ll button it up and clean it up later, why did i fit everything into the front shell of the robot, because the back shell, i had to open up more because my battery a 12 volt now instead of a 6 volt, is larger. I did make one design addition, and that was these tiny micro switches that i’ll mount on the front of the robot itself. They’Re gon na actually act as bumper switches in case it bumps into something. It’Ll tell the arduino that it has connected with something and therefore it needs to back up and get out of the way. They’Ll simply put a high voltage on a digital input to give a good connector for the raspberry pi without having to cut any wires.
I actually hacked into the power cube that came with the pi. I pulled off the ac portion of the circuit, but before i did so, i measured and found that there was 5 volts coming from the ac portion to the dc board. Therefore, i can take the output of my bec, the 5 volts directly into the same board.
Then the raspberry pi can still use its usb wiring to plug in and get the 5 volts for power. Before i button it all up, i want to check to make sure everything works, so i apply power to the system to make sure the raspberry pi boots up and the arduinos power up and everything has the power that requires. I do this using my amp meter in series, so i can take a current measurement of what the system is drawing without the motors running, just to get an idea of what the ala mode, the arduino and the pi use, while in operation. What i found was when the raspberry pi fully booted into its system, that the whole system without any motors running, was taking around 500 milliamps. I’M really glad that i didn’t choose the 7805 in this case and went with the bec’s they’ll. Do a great job of powering the system once everything’s installed, and i am assured it’s working.
I clean up the wiring a little bit and then i button everything back up together that little hood’s kind of difficult to get on. Sometimes then, i go in and put the plethora of screws back in to the body of the robot from there it’s installing the 12-volt battery into its new home and putting in the final wiring, basically the on switch. What i’m left with is a robot that i can control via a web page that it serves up itself. I can tell it to go right, left forward and back or tell it to explore on its own. I can throw it through ssh and vnc, or i can control it through its own display, with a wi-fi keyboard with glide pad. What i started with was an old, robotic toy one that i used to play with when i was a kid it had one direct link, an rf link and a little bit of automation capability, but no digital.
I o to speak of nor analog inputs. I gave it a new brain in a raspberry pi, a new operating system with weezy linux, a little more muscle with an arduino and a motor shield and gave it multiple ways of interface via the web, ssh or even a direct interface. What we have now is an updated robot that can be programmed with automation. Sequences timing can play media has multiple digital, i o and even analog inputs. What we have here now is a platform that we can do almost anything with. We can reprogram repurpose and redo. As necessary by any direct interface, this project was definitely a challenge and there’s a lot to it. If i tried to put everything into this one, video we’d be here for hours, that’s why the links will show you everything you need in programming, hardware connections, references where you can go on the web and different applications.
It’Ll even have a few different ideas of different sensors that you might incorporate later well. I hope that this gives you an idea for your robotic, redo, happy building. You .