I’m just adding a quick comment to this thread for anyone who might read it one day - I don’t think it’s worth a thread of its own. (but Eliot might decide to split it to keep things tidier)
The current consumption rating giving on the Ping1D spec is 100mA typical, 900mA peak. I thought I just needed to support the capacitor in-rush at start up and then it’d be happy. I have a dc-dc convertor boosting from a single lithium voltage up to 5V that I designed to handle 250mA.
It turns out I was wrong.
When BR say 900mA peak they’re not fooling around. The Ping1D hammers the supply rail in little bursts every time it energises the transducer. And it wakes up enabled, so that complicates things too. I’m still working on a solution for this.