Need Help-PIC16F628A

[nleknh]

I want to create an RCD- or a JDM-programmer working on external power supply.I need a working scheme. Can someone help me? My RS232 serial PC port only gives me 10.5 V. I have read on many sites that it's(min. 10 V correctly) enough for programming PIC16F628A. I created and tried these programmers, but they didn't work.So,please help me.

 

[Robin2]

You can program the 628A with 5v using the low voltage programming mode. See Microchips document DS41196G "PIC16F627A/628A/648A EEPROM Memory Programming Specification".

I made up a programmer using an FTDI UM245R usb-parallel module and a 74Hc132 Schmidt trigger chip which was suggested to ensure the on/off happens fast enough. It may work without the -132 but I haven't tried it. I have used three of the UM245R pins as outputs to control MCLR, PGM, Clock and Data and one set as input to read back the data from the -628A. I have written the programming code in Ruby.

 

[colin55]

Here are 3 programmers that work:

PIC-2 USB Burner (USB)
- PIC Programmer (serial port)
- PIC PgmrMkV-12parts (serial)