thank you for prompt reply, I’m helping a maker space get up and running locally and thought this was innovative and cost efficient, The SAMD21 is doing what I want but the problem is the code, I tried circuit python, but it seems I should stay with Arduino IDE. as a basic start to get us running quickly. To stop everybody jumping on the Laser or the Lathe. I thought this was a smart move and within my budget. I got everything to work,Readed, 128x32 OLED and LED. just using the UID but the reader does not see the card is still there… it must see when th card is removed to shut down… and then shuts the LED with card on, after 2 seconds… it shts LED off. been struggling a ;ot as Code is not easy for me but I am trying. I was not raised in this coding world.Thank you for your support, and have a great day I am very new to a Forum this is my first attempt…