And for another time I picked up work on a almost forgotten project: The lawn mower bot (lmb). Together with my girlfriends dad I started this project quite a while ago. He wanted a automatic lawn mower, but we both considered the prices unreasonable high. So we decided to give it a try and started building our own mower. The first part was very easy: take some DC motors from China, mount them on a piece of wood. For the mowing part we used replacement part from a real automated mower. An arduino should become the heart of the lmb.

So far so good, but how do you control the 24V DC motors with the arduino? We needed an H-bridge. As buying finished stuff is boring, we worked out a h bridge on our own. The soldering took quite a while (yes, I am lazy). Yesterday we gave it a try, and I think we fried it pretty well. Somehow I even managed to fry my arduino, as it does no longer talk to any computer. Seems like it did not take 12V on the Vin pin very well…

After this setback I am tired of soldering h bridges (without a method to create real PCBs, it is a real pain with protoboard and all the cables). I am really thinking about buying some H-bridges from China, as they are not really that expensive. It is not a cool as building your own, but at least you can be sure it works.

To be continued…