Universal PIC programmer
The programmer I propose to make can program all PIC circuits accepting programming series circuit or CPSI ie all PIC 12Cxxx, 16Cxxx 16Fxxx and existing and future. The only circuits that can not be programmed are old 16C54, 16C56 and 16C57 to parallel programming, which are endangered. It connects to the parallel port of any compatible PC running at least Windows 95 still only DOS versions of its operating software available on the Internet. It requires a power supply, which may be direct or alternating, between 12 and 30 volts, and which does not need to be stabilized. A power supply "socket" or any laboratory diet may be suitable especially as the required flow rate is less than 100 mA. Given the performance of its operating software, it can read, verify, program and compare PIC with no restrictions, just as it can read and program their "fuses" configuration. He also knows erase circuits equipped with EEPROM and allows access to the data memory circuits with such a memory when in EEPROM technology also. Suffice to say that it is really complete.
Schematic of programmer
My programmer connects to the PC parallel port and complete diagram is shown in the figure below.
The signals being a parallel port to TTL standards and being "abused" by their journey on the connection cables, they are reshaped by inverters contained in IC1. As this circuit has outputs open collector allows easy control of the three transistors T1, T2 and T3. T1 and T2 allow the application of VPP programming high voltage to the appropriate tabs of the universal support of the programmer. T3 controls the normal supply voltage VDD is also applied to the universal support.
This makes it possible to supply the circuit program only when it is really necessary and avoid problems when inserting or sound programming support extraction. Two red LEDs, D1 and D2 indicate the presence of voltages on the support. D3 in turn simply on when the timer is turned on to signal the correct operation of the power supply.
The data to be programmed pass through IC1a IC1b while they go through during a reading of the circuit. The timer goes through IC1c. The support for receiving circuits to program a model 40 is a bit special legs so as to receive the PIC housings: 8, 18, 20, 28 and 40 feet. Wiring different power supplies, the data line and the clock line is performed according to pinouts different circuits.
The power to the controller is simple but very tolerant. Two stabilized voltages are required: to VDD 5 volts and 13 volts for the programming voltage VPP. IC2 is a 78L05 loads of 5 volts while IC3, which is a 78L08, produces 13 volts because it is not referenced to ground but to the output of IC2 and the product thus 5 + 8 is 13 volts! To accept any external source, regulators are preceded by a generous filter and a rectifier bridge. Can be applied to any J1 AC voltage between 12 and 20 volts or between 16 and 30 volts. The flow rate required is only about 100 mA.