I spent a few hours playing “Tinker Toy” with SES brackets, just seeing what I could build, with the general idea of building a small balancing robot. I need something to learn about IMUs with. I have an IMU I got from Adafruit that has a 3-axis accelerometer, 3-axis gyro, and temperature/pressure sensor.
I think I came up with something reasonable, that will work for what I want to do. Below are a few pictures of what I built. I’m going to use CR servos, and a single front ranging sensor. The IMU will be mounted on a proto shield on the BotBoarduino. This may put the IMU too close to other electronics. I’ll have to wait and see how it goes.
I have two CR servos, a set of those nice aluminium wheels, another BotBoarduino and SSC-32, and assorted hardware on order from Lynxmotion, so I hope I will get all of that next week sometime. I am not sure the CR servos are going to work well enough for this little balancer, but I’m going to give it a good go. I have two currently unused GHM-04 motors here that I can always use if necessary. I don’t have hubs for those motors that fit the wheels though. I also have a set of encoders for these motors.
I am considering some design changes in the chassis for this little balancer that will make it a little wider and taller. I might put a 1.5" tube between the U channel and servo/motor mountings. I may also mount an L bracket and connecting bracket from the middle of the U channel (because that’s what I have to use right now), and mount the electronics carrier and battery vertically instead of horizontally. That might even make it possible to mount a pan/tilt on top without over balancing the little bot.
This and various things on W.A.L.T.E.R. gives me a lot to work on when I can’t sleep. That’s quite often lately. I have a lot of new ground (for me) to cover to make everything I want to do work. I will create a new Git repository for this Balancer at some point, as I pull useful code from various places, and write new code of my own.
My chassis is small, so hopefully it will work well. This is just a learning experiment because I need to learn about sensor fusion of various sensor data, filtering, etc. I don’t want to put a lot of money into it and am using as many parts that I already have as possible,
I don’t want to drop products here…
But i do believe in that little board so i want to show you, it’s basictly an Arduino ProMini 16mhz 5v with a MPU6050 i2c on board. (Gyroscope + Accelerometer)
With header pins… of course.
Primarly use for Multicopter running MultiWii OpenSource soft but can be use for anything…
I found some more SES tubing and hubs, so I am going to extend the chassis out 1.5" from each side of the U channel. This way, it will be really easy to convert from CR servos to motors if I want to do that at some time. I want to keep this (still unnamed) little guy pretty close to the ground for now though, and I think that’s a reasonable goal.
I won’t be able to get this little guy up and running until next month, because I wasn’t able to get the parts I need from Lynxmotion. I ran short of funds this month. So, this month is going to be all about W.A.L.T.E.R. 2.0!
This will give me time to consider what I want to do for this robot’s locomotion. I’m seriously considering going to a 12V system, with motors and encoders.
Yes, this is my thinking as well, based on what I have seen and read about other balancing robots. Fast response is required, and I just don’t think CR servos can manage that over the long haul. I believe I can still use those nice aluminium wheels, with universal hubs on the motors.
I will finalize the chassis of the robot this week, and then I can put in an order for just the parts I need to complete the hardware part of the build next month.
I will create a new Git repository for this Balancer at some point, as I pull useful code from various places, and write new code of my own.
So, this month is going to be all about W.A.L.T.E.R. 2.0! 