Playing with bit-bang Ethernet on Attiny85

When going down into Ethernet or any other signal, you find that there is nothing more than ones and zeros. So practically any programmable device theoretically can send any information in any format. The only limit is RAM space, speed and signal conditioning. Cnlohr was able to squeeze Ethernet functionality in to small Attiny85 microcontroller. He was able to do so without external circuits – twisted pair was directly attached to microcontroller pins. This is really dangerous way to do, because Ethernet signal this way is forced to be tied to mcu ground. Ifthere is a DC offset in the line, it can cause damage. Normally there is a magnetics involved in signal line. Anyway this is great hack showing that anything is possible with minimal component count and small processing power. Attiny is clocked at 20Mhz and uses one twisted pair for network connection. IT is recognized as 10MBit Ethernet switch that can send hard-coded packets once one of couple buttons is pressed. To get 10MBit from 20MHz micro thee is an assembly language involved. As it is said,… Continue reading

Scanalicious – The Advanced 3D Scanner for Everyone!

Read it carefully; it’s not “Scandalous,” but “Scanalicious,” which is the combination of “Scanner” and “Delicious” (Sounds very interesting, isn’t it?) The main objective of this “Scanalicious” is to build an effective yet low-cost 3D scanner. The project implements the hardware is necessary for a laser triangulation 3D scanner. A PC interface is being used to control the scanner and acquire data via an Ethernet connection. This “Scanalicious” scanner facilitates 360 degrees scans through the implementation of a rotating sample platform. Normally, each rotation position is scanned by using a linear actuator to increase the resolution, becoming better and sharper. The scanner is capable of producing all data, which is necessary to compute and construct 3D representations. Well, the 3D scanner might not be new technology, but at least it’s affordable, especially for home hobbyists or small business owners. In most cases, we can build a 3D scanning hardware package and computer control interface for under $75. gn. Hence, a 3D scan provides more complete representations, which are unavailable to the ordinary person. With this unbeatable low price, the systems… Continue reading