I should sell a stock of a access control system interfaces based on raspberry to a US customer. The customer asks me the ul certification. Here in Italy, to have the ul certification a company has askd to me something such as 8.000 € plus vat ad related costs.
My system based on raspberry pi, wants 12v dc, a ethernet cable, can manage 4 doors at 12 - 24 v dc or ac.
Do you know a way to have the ul certification but a minor price?
See the attached interface img.