Quadrature encoders are used to provide feedback about position or speed of rotating elements within mechatronic system. Wikipedia is a good source of knowledge about them: https://en.wikipedia.org/wiki/Rotary_encoder .
As you can find in a hardware documentation of CORE2, 4 quadrature encoders can be handled by a hardware. That means you don’t waste CPU power on processing input signals and don’t need to worry about losing encoder ticks, even if input signal frequency is in hundreds of kHz. But can we get a feedback from more than 4 encoders?
Continue reading How many encoders CORE2 can handle?
There are variety of platform robotic developer can choose. Most of enthusiasts usually have problem with selecting right controller for their projects, just because they don’t know the differences between all of them. We hope these series of articles will make that decision much more easier.
The mission called “hand-in-hand” involves tracking the current position of target. Our criterion of comparing will be one of the most important task in robotics, it’s mean establishing position of mechanical parts. A seemingly simple task poses even the best drivers much trouble. This is not a problem to achieve by the servo target position, but perform this task in real time with the shortest possible delay. We have used 4 LEGO motors: mechanical connected encoders from two of them were reference signals for both devices, CORE2 and EV3. Another two were executive objects for controllers.
Continue reading CORE2 vs EV3 comparison – Quest #1
Ralph telepresence robot in version with RoboCORE is equipped with battery pack for 6 x AA batteries. Because of high current consumption, especially when starting, it needs good enough power source. At least it should be alkaline batteries. The next problem is a low capacity of AA batteries, even alkaline. There are Li-Ion AA batteries available, but their voltage is 3.7V, so you can not use 6 Li-Ion batteries because their total voltage (6 x 3.7V = 22.2V) is too high for RoboCORE. Three Li-Ion batteries in series (3 x 3.7V = 11.1V) would work fine but you need to short-circuit three compartments in a battery holder. Although you can buy AA battery placeholders, it is really hard to find them.
The most reasonable choice it to replace 6 x AA battery holder with Li-Po or Li-Ion rechargeable batteries. There are variety of different battery types, but we recommend using 18650 protected Li-Ion rechargeable batteries. They are quite easy to buy together with a charger, especially in e-cigarette shops, but there are also becoming popular in DIY and electronic stores.
Continue reading Upgrade you Ralph self-balancing telepresence robot