Old 28x2 and 16mhz resonator

[kd5crs]

I bought a couple of 16mhz resonators to use with my 28x2 so it would run at em64. But when I tried it, doh! I have one of the older (firmware B.0) 28x2s that only go up to em40, which would need a 10mhz resonator, which I don't have.

Is there anything I can do with the 16mhz resonator and the 28x2 I have to get a speed higher than the internal 8mhz?

Thanks.

 

[nick12ab]

The old 28X2 will work with the 16MHz resonator - just use setfreq em40. You will be overclocking it and there's a risk that after a while or with a small power brown out the PIC will switch back to its internal 8MHz oscillator.

You can also use the PICAXE at 16Mhz by pokesfring the osctune register to disable the PLLEN bit and using the 16MHz resonator. You still need to use setfreq emxx with that.

 

[geoff07]

I think not. Unless, just maybe, you program in C and fiddle with the config bits. But you really don't want to do that, and I think you would only be able to get the native resonator speed anyway i.e. 16MHz because if it won't run at 64MHz you would have to turn off the PLL. Buy another chip or resonator! 10MHz resonators cost 46 pence (plus a large dollop of postage). Or try a salvaged 10MHz crystal plus capacitors if you can find one.

Edit: Hmm. Never was a fan of overclocking. But if it works ...