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PICAXE bootstrap vs. "blank" chips

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lukas.ballo

New Member
I was working with PICAXE chips some time and now I would like to buy some other PIC microcontrollers called "blank" since they don't have the PICAXE bootstrap pre-programmed. Is there any way to burn the bootstrap into the microcontroller's PROM memory? What other method than the PICAXE software can be used to program "blank" microcontrollers?

Thank you for any ideas.
 
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3v0

Coop Build Coordinator
Forum Supporter
You can program them in ASM C C++ and several falvors of basic to mention a few languages. These all require a device called a programmer to write the program to flash memory.

If you want to stick with a BASIC there is one similar to what you are using or there is a more advanced one called SWORDFISH BASIC that you may or may not be comfortable with.

I do not know of a way to convert a blank pic into a picaxe. The people who make it do not want that to happen.

The good news is that any of the above will be much faster and execpt for the one time purchase of the programmer much cheaper.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
PICAXE's don't have a 'bootloader', they have an internal BASIC interpreter, fairly obviously the device is copy protected to stop you stealing the code and making your own, however they are remarkably cheap anyway.

As already suggested, use blank PIC's and a BASIC compiler, this will be many times faster and much better featured than a PICAXE.
 

lukas.ballo

New Member
Thank you for help, I did some additional research on the programming hardware needed for PIC's and I found out about Low Voltage Programming (LVP) that can be used with some very simple circuitry however it says that it works only with "natural" serial port. There are apparently some limitations in voltage that can be generated by "un-natural" serial ports (such as USB-to-serial adapters). They were saying about "voltage levels -10V and +10V sent back to the PC" and "high-low threshold voltage +2V". So what is the reason why a simple LVP circuit can not be used with USB-to-serial adapter? Can this issue be resolved by adding a quad comparator and an external 5V regulated power source?
 

Sceadwian

Banned
A USB serial adapter that meets Rs232 specs should work. RS232 is +12/-12 and the threshold is supposed to be +3/-3 for a logic change. If you can change the DTR/DSR flags on your serial port you can measure the high/low voltages directly with a multi meter. A serial program like Bray's terminal is quiet handy to have.
TERMINAL - terminal emulation program for RS-232 | HW-server.com
 

lukas.ballo

New Member
OK, so the USB-to-serial adapter can generate voltage up to 12V. But why is this necessary for Low Voltage Programming? As far as I know, this method requires only 5V to be applied on PGM pin and data to be transferred with regular 3V threshold through PGD clocked on PGC. There should not be any higher voltage than 5V necessary.

On this website they say that the LVP circuit didn't work with "unnatural" serial port. What can be the reason?
http://home.vrweb.de/~lotharstolz/stolz.de.be/lvpc/index.html
(See 4th paragraph, right from the blue box)
 
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Sceadwian

Banned
Beats me lukas, I have no idea where you're getting your info from. Maybe it's like some RS232 programmers I've seen out there and actually draws power from the serial port lines.
 

blueroomelectronics

Well-Known Member
You need a genuine RS232 port for simple JDM style programmers and they still may not work. Lothar Stoltz's ICD2 clone (which my Inchworm is based on) is a HVP programmer and the design does not like most USB / RS232 adapters (poor timiming emulation).
A modern USB design like the PICkit2 or my Junebug work very well with modern Windows computers (XP, Vista)
 
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