Review on KEYESTUDIO 4 Channel Relay Shield 5V: Arduino R3, ARM, PIC, AVR, STM32, Raspberry Pi Expansion Board by Zane Myers

Last update: KEYESTUDIO has added the missing pin/connector information to the description as I originally checked and complained. Pinout information for using the Keystudio 4 Channel Relay Module Shield; The Keyestudio Relay Shield features a built-in 4-channel 5V relay module that is fully compatible with the UNO R3 control board. The 4-channel relay on the shield is active at HIGH level. Connect the 4-channel relay separately to the digital port. 4, 5, 6, 7 on the UNO R3 board, then through the HIGH or LOW control output to turn the relay on and off. "I hope this helps. Otherwise it's a pretty good board. Update: Here's a quick sketch I wrote in my desperation because the manufacturer didn't provide basic information on the digital outputs used. It tests each relay for 1.5 seconds Then it goes down and on to the next in line It just goes on and on Copy and paste into your IDE Ugly and elegant but suitable for the task at hand int RELAY1 = 4;//Relay -trigger output pinint RELAY2 = 5;//relay trigger output pinint RELAY3 = 6;//relay trigger output pinint RELAY4 = 7;//relay trigger output pinvoid setup() { pinMode(RELAY1, OUTPUT ); // initialize the output of relay strobe as OutputpinMode(RELAY2, OUTPUT); // initialize the output of relay strobe as OutputpinMode (RELAY3, OUTPUT); // initialize the output of relay strobe as OutputpinMode (RELAY4, OUTPUT); // relay strobe output as output initialize } void loop() { digitalWrite(RELAY1, HIGH); digital input (REL2, LOW); digital input (REL3, LOW); digital input (REL4, LOW); delay(1500); digital input (REL1, LOW); digital input (RELAY2, HIGH); digital input (REL3, LOW); digital input (REL4, LOW); delay(1500); digital input (REL1, LOW); digital input (REL2, LOW); digital input (REL3, HIGH); digital input (REL4, LOW); delay(1500); digital input (REL1, LOW); digital input (REL2, LOW); digital input (REL3, LOW); digital input (RELAY4, HIGH); delay(1500); }