AVR microcontroller parallel port ISP download line circuit schematic

Single chip microcomputer STM32L151CCU6

1206RGB (single)

0201 package SLP0603 ESD electrostatic diode 5V one-way ESD

Imported spot passive patch crystal oscillator 3225 2520 40.000MHZ

SMD aluminum electrolytic capacitor

In order to give AVR microcontroller amateurs, especially college students DIY an ISP download line, you can develop all AVR series AVR microcontrollers in one line, and provide two kinds of mature circuits for DIY. It should be noted that the circuit wiring and the power supply cannot be connected incorrectly, resulting in damage to the device. SL-DIY series function boards, some with ISP parallel port download cable.
Figure 1 The simplest ISP parallel port download line schematic

Figure 2 Standard parallel port ISP download socket wiring function diagram

Figure 3 Parallel download line schematic with signal isolation