Months ago I received a proposal to build a seed counter project together with somebody for an internet seeds seller. I would take care of the electronics, design circuits, electronic parts and software of the controller. The other person would take care of the physical layer, building the machine itself, manufacturing the pieces assembly and the mechanical logic behind it. The intention was to create a machine able to count seeds of different kinds and automatically place them into plastic blisters ready to ship to customers. So it is actually an invention from scratch. We need to think about how to do thinks, how to control the parts to do the things we want, and put them all in place so they will work as they suppose to. In essence it is building your own mini robot. You give him a way of thinking and a body, and he needs to do the rest by itself. A piece of art with artificial intelligence.
Here comes the technical part:
The fysical layer of the system couldn’t be simpler. It uses basically a pump system to suck the seeds into a small hole and stik it to it. Then moving this hole to another place and stopping the pump releases the seed and so falling into another place. In the middle an optic sensor makes sure that a seed is attached to the hole avoiding false positives.
The first step was pretty complex, building and testing the early prototypes of the counter.
After 2 months of testing with several designs my friend got the first working prototype. In the picture below its not clearly noticeable but there is already the optic sensor attached and the stepper motor for moving the wheel where the little hole picks the seeds.
Once we had the counter ready we started building a XY table that would move all the blisters in order to fill all the different holes with seeds.
The table is driven by another two stepper motors, one for each axis. There are two optic sensors in each axis that detects the initial position of the table. This allows the table to go to any position from any position. All the motors in the system are using an algorithm to create acelerated movements. This way the movements are smooth and lees likely to lose steps. The sound is decreased thanks to the elimintaion of resonances and consumes relatively less power. This algorithm has been taken from the AVR446 file from Atmel and adapted to the arduino platform.
The seedcounter has been working with the XY table for a while now (and works well), it already looks quite impressive. We are now ready for the next step.
My friend has already designed the new setup wich will automatically seals the blister packaging.