Any new chips? More RAM? Faster Clock?

SolidWorksMagi

Senior Member
Hi,

Is it possible to program newer chips with the PICAXE Loader to have more memory for programs, a faster clock?

8K of flash RAM would be really nice for larger more complex programs like this HexBot I made;

20210717 HexBot+Maestro12 Test6

After converting the 3-color LEDs to just direct PIN high/low the program uses 4043Bytes. No room to control the gripper or the upper Pan&Tilt let alone any kind of device on the Pan&Tilt.

6K or more memory would let this robot become autonomus rather than IR remote control.
 

AllyCat

Senior Member
Hi,

Often, programs posted to the forum can be coded more efficiently to save program space and maybe run faster (because less instructions are executed). Or, the use of suitable Subroutines can save a lot of program space, although these generally will NOT improve the speed. Normally, 64 MHz (i.e. SETFREQ M64) is the maximum speed for X2 chips, but note that certain commands such as IRIN and RFIN may force the speed down to 4 MHz (at least whilst they're executing).

However, IF you can partition the program into clearly separate "Modes", for example "Walk", "Gripper", "Pan and Tilt" or "Flash LEDs", etc., then you can use the 4 "Slots" as shown by PieM, by executing the RUN and related commands, to give up to "16 kBytes of Program Space". But it's not my preferred solution because it largely prevents the use of Subroutines and Multi-Tasking methods, etc..

Cheers, Alan.
 

westaust55

Moderator
Albeit not RevEd/PICAXE warranted
(= do it at your own risk)

I have four 28X2 chips clocked at 80 MHz by using a 20 MHz external resonator since about 2015 without any failures.

hippy has posted also similar time ago that he had successfully run a chip (28X2?) at 100 MHz hence my 80 MHz is still not at the peak of speed.

I reiterate the warning that you void warranty in doing so.
 

AllyCat

Senior Member
Hi,

Just a further thought: The OP appears to be using (or planning to use) the SERVO{POS} command which (normally) can be used ONLY at SETFREQ M8 or M32 (32 MHz) with a 28X2. The Servos probably need to be switched OFF before using any other clock frequency. From the Manual/Command list:

"Effect of increased clock speed:

The servopos command will function correctly at 4 or 16MHz (8 or 32Mhz for X2 parts). No other frequency will work correctly."


The X2's optional "[preload]" constant/variable parameter might give a partial solution if "Over-Clocking" the PICaxe.

Cheers, Alan.
 
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