DSO150 Playing with floats & speed

 

My version of the DSO 150 firmware is using float internally to convert ADC to voltage.

It could probably be faster using 32 bits fixed point, but float is good enough for now.

Let''s see how it evolves, the basic test is converting 240 samples from ADC to voltage

For each sample the formula is OUT=IN*multiplier - Offset


STM32F103 overclocked to 128 Mhz

"Old code" : 880 us

"Newer code" afer optimization : 440 us

Using fast float lib (qfp) : 380 us

So twice as fast, not bad


GD32F303 at 96 Mhz

It is a cortex M4 core with FPU

"Newer code" without FPU : 350 us

"Newer code" with FPU : 83 us








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