For the last two summers I've been trying to use the cheap hobbyist's relay boards in a farming IoT application. Things would go alright until hot humid weather and then there would be problems. So I looked into using solid state relays. Individual relays cost a lot more and take up a lot of room. Then I found this 8-SSR board at Sainsmart.
So I bought one. The web page didn't explain the connectors but maybe documentation would be in the shipping box. Dream on! So I emailed Sainsmart, twice. No response -- it's been 2 weeks.
I supposed that wiring it up wrong might fry the board, but what-the-hell. On the output side there are only 2 choices: got it 2nd try. On the control/input side there are 10 connectors. Makes sense: 8 GPIOs, 3.3v and ground. I assumed that the 8 controls would be together and the + and – would be on either end -- 4 possibilities. I got it 3rd try.
I'd have liked to send it back but it works and I need it. What I didn't need was having to figure it out. I am extremely irritated with Sainsmart. And won't buy from them if I can help it.
