PIC18 programmer

The SCHAER+ programmer is a programmer for PIC18 family from a PC parallel port (LPT). It is derived from the SCHAER programmer I used to download my projects in PIC1684. The SCHAER+ programmer should be improved to use a USB connection, without any external power supply. The SCHAER programmer I'm currently using allows me to program chips like PIC16F84 by managing 5 signals through parallel port.

More: VCC: switch ON or OFF the chip to program VPP: apply the program power supply on VPP pin DATA_IN: serial data transmission (PC -> PIC) DATA_OUT: serial data transmission (PIC -> PC) CLOCK: clock transmission The original circuit has been designed for PIC16F84. A special adapter for chips with 20 and 40 pins has been necessary. The main modification of the layout concerns the activation of the VPP signal, firstly generated by 2 signals.

The SCHAER+ programmer is designed for programming microcontrollers from the PIC18 family using a parallel port (LPT) interface, which offers a straightforward method for connecting to a PC. The design is based on the earlier SCHAER programmer, which was utilized for programming the PIC16F84 microcontroller. The primary enhancement in the SCHAER+ version is the transition to a USB interface, which eliminates the need for an external power supply, thereby simplifying the setup and enhancing portability.

The circuit employs five essential signals for programming operations. The VCC signal is responsible for powering the microcontroller, allowing the programmer to switch the device on or off as needed during the programming process. The VPP signal is critical as it applies the programming voltage to the VPP pin of the microcontroller, which is necessary for entering programming mode.

Data transfer between the PC and the microcontroller is facilitated through two serial data lines: DATA_IN for transmitting data from the PC to the PIC, and DATA_OUT for receiving data from the PIC back to the PC. The CLOCK signal is used to synchronize the data transmission, ensuring that data is sent and received accurately.

The original circuit design was tailored specifically for the PIC16F84 microcontroller, necessitating a special adapter to accommodate chips with 20 and 40 pins. The modification of the layout for the SCHAER+ programmer focuses on the activation of the VPP signal, which was initially generated by two separate signals in the original design. This adjustment is crucial for ensuring compatibility with the newer PIC18 family of microcontrollers, which may have different programming requirements compared to their predecessors.

Overall, the SCHAER+ programmer represents a significant advancement in microcontroller programming technology, combining ease of use with enhanced functionality for modern applications.The SCHAER+ programmer is a programmer for PIC18 family from a PC parallel port (LPT). It is derivated from the SCHAER programmer I used to download my projects in PIC1684. The SCHAER+ programmer should be improved to use a USB connection, without any external power supply... The SCHAER programmer I'm currently using allows me to program chips like PIC16F84 by managing 5 signals through parallel port.

VCC : switch ON or OFF the chip to program VPP : apply the program power supply on VPP pin DATA_IN : serial data transmission (PC -> PIC) DATA_OUT : serial data transmission (PIC -> PC) CLOCK : clock transmission The original circuit has been design for PIC16F84. A special adpater for chips with 20 and 40 pins has been necessary. The main modification of the layout concerns the activation of the VPP signal, firstly generated by 2 signals.

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