Summary of Programmer using PIC16F84 microcontroller
This article describes a very simple, low-cost serial programmer for the PIC16F84 microcontroller that works with Nigel Goodwin’s WPicProg V1.20 software. It explains the hardware design using LPT1 (parallel port) control of Vdd and Vpp via transistors and diodes, deriving Vpp by lifting the 78L09 ground, and using RB7/D0/ACK/D1 for data and clock. It also references obtaining WPIC16.ZIP from Nigel’s site and notes DC input should be about 17V.
Parts used in the F84-Programmer:
- PIC16F84 microcontroller
- 2N2907 PNP transistors (for Vdd and Vpp control)
- Diodes D2 and D3 (inversion/control diodes)
- 78L09 voltage regulator
- Resistors (various, for transistor/base/current limiting)
- Capacitors (for regulator and decoupling)
- Parallel port connector (LPT1 interface)
- DC power input supply (approximately 17V)
- Wiring/PCB or breadboard
- Optional sockets for PIC16F84 and connectors
Build a low-cost and very simple serial programmer for a PIC16F84 Microchip Flash Microcontroller. Below picture is my personal writer for F84 chip, it works very nice with Nigel WPicProg V1.20.
Introduction
I finally found a very nice universal window based software designed to work with any serial programmers for PIC16F84, i.e., WPicProg16 V1.20, written by Nigel Goodwin. Build this programmer before started experimenting the forthcoming many interesting F84 projects. Some PIC programmers can be used for in circuit programing, some provide many PIC chips including eeprom, say. The F84-Programmer, however is suitable for beginners. It’s so simple and cheap.
Hardware
Figure 1 shows a circuit diagram of the F84-Programmer. The programmer connects some bits shown in the figure through printer port LPT1, say. Vdd is controlled by D2 with invert setting, logic ‘0’ at this pin turns 2N2907 on applying +5V to pin14. Similarly for Vpp with invert setting, D3 controls 2N2907, gating approx. +14V to MCLR pin. A programming voltage Vpp is derived by lifting GND pin of the 78L09 to +5V as shown. Data read and write use RB7, D0 sends serial packet while ACK reads back during verify. D1 is clock output synchronizing programming flow. DC input should be approx. 17V.
Software
WPIC16.ZIP Updated zip format of window version software for F84-Programmer written by Nigel Goodwin. The Latest WPIC16.ZIP may get directly from Nigel’s Software page.
For our F84-Programmer, check hardware settings window as follows;
For more detail: Programmer using PIC16F84 microcontroller
- What software works with this F84-Programmer?
WPicProg16 V1.20 (WPIC16.ZIP) by Nigel Goodwin is used with this programmer. - How is Vdd controlled in the circuit?
Vdd is controlled by D2 and a 2N2907 transistor; a logic 0 at the printer port pin turns the 2N2907 on to apply +5V to pin 14. - How is the programming voltage Vpp generated?
Vpp is derived by lifting the ground pin of the 78L09 regulator to +5V as shown in the circuit. - What voltage should the DC input be?
The DC input should be approximately 17V. - Which PIC pins are used for data and clock?
Data read/write uses RB7, D0 sends serial packets while ACK reads back during verify, and D1 is the clock output. - Can this programmer perform in-circuit programming?
The article notes some PIC programmers support in-circuit programming, but this F84-Programmer is a simple beginner-friendly design; it does not specify in-circuit capability. - Where can I get the programmer software?
The latest WPIC16.ZIP can be obtained from Nigel Goodwin's software page.
