Hamamatatsu C12880MA, get a little integration time

Hello, I am using the Hamamatatsu C12880MA and I used these arduino codes:


The problem is that when I want to observe the spectrum, the spectrometer is way too sensitive and then even the natural light makes it saturate. I have been studying the timing chart in the following datasheet:
https://www.hamamatsu.com/resources/pdf/ssd/c12880ma_kacc1226e.pdf
I want to change the integration time (IT) because I suppose that this one is too big. for that: since IT = 48Tclock + thp(ST), then for this given program the integration time is 134usec and it is almost the minimum limit fixed by (482 + 6*2=108 usec).
Finally I don’t know how to manage to get a non saturate picture, should I change the hardware and not use arduino ?
Thank you for your help !