Spintly, an IoT-based wireless access control startup, has raised Rs 1.9 crore in a Pre-Series A funding round from early-stage US angel investors, led by a technology angel investor group and Saltwater Venture Sparks, a Goa-based venture accelerator. This investment will be used to scale up sales, marketing and research activities to accelerate customer acquisition and market penetration, Spintly said in a release.