I know this is an old thread, but I'm looking for some clarity as I keep reading conflicting things.
I'm trying to power a Sainsmart Optoisolated Relay (there's 2 of them on the board). I'm using the normally closed function. I just want to be able to apply a signal to one of the pins to turn the relay off. (or rather the device by pulling to the 'Open' function of relay)
The relay is 'SainSmart 2-Channel 5 V Relay Module Board for Arduino PIC AVR DSP Electronic Relay Module MCU' from Amazon - (https://www.amazon.co.uk/gp/product/B00 ... UTF8&psc=1
I am trying to power the relay from the RPi3, using the 5v and 3.3v. 5v as the JD-VCC, and 3.3v as the VCC (as per this guide) - https://github.com/foosel/OctoPrint/wik ... m-your-RPi
Now, this is where I'm confused as what I have seen written here that says leave the jumper between (JD-VCC and VCC)
I am using a transistor the BC548B NPN transistor that I picked up at Maplins. I've tried applying a 1k pulldown resistor, however upon reading this is for 'Active High' and this relay is 'Active Low'
Should I be using a 2.2k resistor and a 10k resistor (as shown in one of the earlier posts in this thread).
So my questions are:
- Do I leave or remove the jumper from the relay board?
- Are the resistor values still the same for RPi3 and the BC548B transistor?
Any clarity (quick yup or otherwise) would be greatly appreciated before I got and source additional parts.