The objective is to find the best pulse pattern for this.
Here, we have Pon ~ 16 at best. No matter was the other is.
Well ! That's 16/128 ~ 8MHz, the double of the piezo (around 3.5 to 4MHz), so no surprise here. POn corresponds to half a wave for the piezo.
Raw files for a 32 lines acq (interleaved) are here for json and here for zipped.
No raspberry pi plugged in. Two jumpers in.
With Pon fixed at 16..
With Pon and Poff at 16..