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

For AVR microcontroller enthusiasts, especially college students looking to build their own ISP download cable, this guide provides two ready-to-use circuit designs that allow development of all AVR series microcontrollers with a single line. It is crucial to follow the wiring instructions carefully and ensure the power supply is connected correctly to avoid damaging the device. Some SL-DIY function boards come with an ISP parallel port download cable for convenience.

Figure 1 shows the simplest ISP parallel port download cable schematic. This design is ideal for beginners who want to get started quickly with minimal components. The schematic includes the necessary connections for programming and communication between the programmer and the target microcontroller.

Figure 2 presents the standard parallel port ISP download socket wiring diagram. This version is more detailed and suitable for users who want a stable and reliable connection. It includes proper signal routing and protection mechanisms to ensure safe operation during the programming process.

Lastly, Figure 3 illustrates a parallel download line schematic with signal isolation. This design is particularly useful in environments where electrical noise or interference could affect the programming process. The isolation feature helps protect both the programmer and the target device from potential damage due to voltage spikes or surges.