Low cost ICSP PIC-programmer using PIC16F648A
Galvanic from PC isolated PIC programmer
The Wisp648 from www.voti.nl is an In Circuit Serial Programmer to program a flash PIC which mostly can stay in your circuit.
No irritating doings like pulling the PIC out of the PCB, place it in the programmer, programming it, pull it out the programmer and place it back in the PCB, over and over again, it can stay in the circuit on your breadboard or PCB while programming the PIC.
It becomes risky when the PIC is connected direct to 230V main, like the wireless controlled (and trafo-less!) dimmer from this site, then it’s better to program the PIC separate from the circuit.
Another solution to protect your PC is to isolate the Wisp648 programmer galvanic from the PC or to build the Galva-Wisp, that’s the Wisp628 but galvanic separated by two dual-optocouplers.
The Galva-Wisp is expanded with a green power on LED, a red program LED and a pushbutton for the possibility to reset the programmed PIC manual.
By the way, the manual reset is only possible when MCLR is enabled. (CONFIG MCLRE_ON in PIC-Basic (= default))
The difference with Galva-Wisp MARK I is that MARK II has no MAX232 chip anymore.
The Galva-Wisp takes his power from the target PIC circuit (where the PIC stays which has to be programmed) (5V/20mA) and the RS232 COM-port (+/- 9V…12V).
The PIC which must be programmed can stay on his own PCB (or breadboard) while programming it, see the pictures underneath.
To connect the programmer with the PIC which must
be programmed you can do it with wires but it is more easy
when using a DIL-clip.
Programming the PIC is then also possible when the PIC is
already soldered into a PCB (see pictures above this one).
The cable on the DIL-clip should not be longer than 1 metre, recommended is a cable with a shield on each wire (see picture).
|PCB 130101||Etch it by yourself (31mm x 53mm) (Etch manual on the Dutch section)|
|IC1||PIC16F648A – Download the HEX file on the bottom of this page|
|IC2,IC3||PC827 (of LTV827) (dual optocouplers)|
|LED1,LED2||Green and red LED, Ø3mm, low current type|
|T1||BC547 NPN transistor|
|T2||TIP120 NPN darlington transistor (see text)|
|D1,D2,D3,D4||BAT85 Schottky diode (if not available, then 1N4148)|
|D5||SB140 Schottky diode (or SB130, or 1N5819)|
|C1||1000µF / 6,3V or 10V (radial) (see text)|
|C2||100n, axial (comes under IC1, in the IC socket)|
|S1||Reset push button (may left away)|
|Conn1||15-pole sub-D connector, male|
|Conn2||9-pole sub-D connector, female|
|IC-socket||18-pins, own choice|
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