Wednesday, November 14, 2012

New speed measures on latest firmware 1.2e


It was time to test new higher serial baud rate speeds today. I reached up to 230400bps with no problems. I used a logic analyzer to capture the serial input next to the loop cycle of the firmware.

I got a really good surprised by the results as with the constant improvements, I forgot to check how fast the main loop speed was going.

Just to say that now the refresh rate is 1666 times per second!!! So the main loop is running now in 1.666KHz !!

Also you may notice that since the serial input is not reside on the main loop but in an interrupt, the main loop is actually faster than the 1KHz update rate of the serial data.

Have a look on the capture screens for 115200bps and 230400bps speed.

 115kbps serial speed detail

  115kbps serial speed 


  230kbps serial speed detail

 230kbps serial speed

The above measurements are with ADC inputs as position input.

Now lets see what happens with digital encoder as position inputs:

The average loop cycle of the main program is around 5000 times per second now (5KHz). The variation is because of the extra delay introduced during receiving data packets.

Thanks for looking,

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