Tait Serial Programmer
ORIn 'Ports (COM & LPT)' the 'Prolific USB-to-Serial Comm Port (COMx)' willappear.7) Right-click on the entry with the error to open a window and select'Update driver software.'
If you.really. want to build a programmer, it is possible to build a PICkit 2 that will work with MPLAB. The schematic is in the user guide and the firmware and standalone application are open source. You either need access to another programmer or to cobble up a dumb programmer (e.g. JDM) to get the initial firmware into the PIC18F2550, but a JDM programmer is simple enough to build on breadboard.All dumb serial programmers are crap as there just aren't enough output pins on the PC DE9 serial connector to control te ICSP signals properly. Some PICs require Vdd, /MCLR(Vpp) PGC and PGD (total 4 signals)all to be controlled with tight timing for reliable programming but the PC serial port only has 3 output pins.
The usual omission is Vdd control which often makes it very difficult or impossible to reprogram any device running from internal oscillator with /MCLR disabled. Programmers controlled by a parallel port avoid this issue.You will almost certainly end up spending more to build your own programmer than a reputable PICkit 2 ot 3 clone costs.N.B. All 'dumb' programmers (i.e.
Those not containing a preprogrammed MCU) need a PC with legacy ports (i.le. Not USB serial or parallel adapters) and usually don't work with Windows 7 or 8. The PIC kit 2 is well worth buying. It has the logic analyser and UART tool as well.I used the serial port one for a long time. 10 years ago, loads of people wrote PIC programmers.Getting it to program the 16F877 took over a year.
I agree with Ian. It only worked when I used a particular length of twisted CAT5 cable! It must have slowed down an edge to get the timings to work.I brought a USB serial lead and my programmer started fast and went really slow as the USB buffered the modem control lines.10 years ago, loads of people wrote PIC programmers, then the PIC Kit 2 came out.If the challenge of pushing your code into the chip is want you want, it is a worthy challenge and satisfying when you read back what you programmed in.Adding this serial monitor code allowed some simple debug.It made the chips a lot more accessibleregards, Doug. I posted the Tait Classic Programmer schematic in a similar topic a while back. It shows how to use a 7812 regulator for Vpp.If you have an older PC with a real parallel port the Tait Classic is still viable as a programmer. I wouldn't bother with most other dumb programmer designs except maybe to breadboard a JDM programmer to bootstrap myself to a USB programmer.
It certainly doesn't make financial sense to build a programmer except in the very few countries with ridiculous duties on electronic imports. Feel free to waste your time and money building a bit-banged serial programmer then trying to make it work with a crappy USBRS232 converter. Even the best quality converters are horribly slow at bit-banging and cheap ones simply wont work with most of the programmer designs out there. It will be a useful learning experience for you - when re-inventing the wheel, don't make a square one! Better to find an old PC with legacy ports and forget about USB unless you can build a PICkit 2 clone or other smart programmer.P.S. If you need to post links, schematics etc. Read: - workaround for restrictions.
Tait Serial Programmer Software
Because a PC chipset's compatible UART doesn't know how to 'talk' SPI, let alone Microchips SPI-alike ICSP protocol. It has to be implemented by diddlng the handshake lines in software one siglal transition at a time. It takes a minimum of three commands to the PC UART just to read or write a single bit.If your old PC has a parallel port do try a Tait Classic programmer once you have discovered the deficiencies of bit-banged serial programmers!
There are various possible substiutes for the 7407 if you cant find one.