This is my first time using the AVR. I like to learn using the ATTiny 2313, because it is faster than MCS-51, cheap and the circuit is very simple. The chip has only 20 pins. I was interested because I want to build a simple line follower robot controlled by this MCU. Board Construction The circuit has built in voltage regulator, the LM7805 and the ISP Header for program loading. The DC input circuit also has protection diode 1N4002. DOWNLOAD EXPRESS PCB FILE: AT-Tiny2313.zip Figure 1. Hardware Schematic Notes: 1 The XTAL can be 4MHz, 8MHz, or 11.0592MHz. 2 DC input voltage using the AC adapter can be 6V-15V. Figure 2. Component placement. ISP Programmer The ISP loader cable can be made easily from the circuit shown in Figure 3. The connector is DB25 male type. The cable length should be less than 1m. This loader is compatible with most of the desktop LPT port.