What has happened since last update? I've ordered some more components and still waiting to get those. While waiting I studied how to use FreeCAD and designed first draft of the robot.. What do you think?

I will make some changes to that, at least reduce the width but before that I need to make some tests with the motors. Motor has encoder implemented using hall sensor and magnet. The magnet is attached to the motor shaft. If motors are too close they might disturb other motors hall sensor.. but let's see. I know more after I've checked how close those can be.

What is still missing is place for different sensors and battery. I placed Raspberry Pi 2 and motor controllers already but their place might change. Also some more ventilation holes might be needed.

The IMU sensor (accelerator meter, gyro, compass and altimeter) place has not been decided yet. Maybe best place is far away from motors. As you know compass uses magnetic fields.. Motors cause disturbances, and those encoder magnets too.. so let's see how these work.

I was about to order A/D converter for this project but after reading the motor controller specification I noticed that it has AD converter for analog control. It is continuously reading the ADC. I can use this ADC and no need to order. The ADC's will be used for converting Sharp IR sensor analog readings to digital.

Also I was thinking that maybe I have to have some temperature sensor for checking the internal temperature of the robot. If it gets hot in there, I should stop the robot. I noticed that the motor controller has temperature sensor too so no need to order any sensors and converters for that either.

I first planned to make the robot inside air ventilation tubes but current plan is to use 3D printer to print the whole robot. Printing material is ABS and it will be much lighter than the air ventilation tubes. The material is black.

The robot arm inside the robot... Seems that with these measures it is not possible to make robot arm inside, but outside.. like hands could be. So maybe I add some ready places for hands.

Next steps are checking the design, placing all components in place, make robot narrower if possible, maybe increase the radius to make some room.