Cheap Chinese Closet Controller

Two out of three solenoids are "burned" / jammed at this point. When I was cutting the switch connectors off of the locks, I didn't check the wiring. Some of the connectors had switched red and black wiring. I first thought my 700mA was not big enough, but it died regularly when two coils where powered at the same time.

Now I only have a problem where my signals aren't strong enough every 9/10 times. Two times out of those it will recognise something, but then the checksum must be bad as it doesn't do what it was told. 

Not yet sure how important that is, but I found a 4k7 pulldown resistor on the A+ connection of the relay board. The 4k7 resistor connected to B- leads to nothing an unpopulated resistor footprint. The chip itself seems to be a MAX485.

Biasing and termination resistors in a story factor with oscilloscope pictures:

http://support.fccps.cz/download/adv/frr/RS485/RS485.html

Two out of three solenoids are "burned" / jammed at this point. When I was cutting the switch connectors off of the locks, I didn't check the wiring. Some of the connectors had switched red and black wiring. I first thought my 700mA was not big enough, but it died regularly when two coils where powered at the same time.

Now I only have a problem where my signals aren't strong enough every 9/10 times. Two times out of those it will recognise something, but then the checksum must be bad as it doesn't do what it was told. 

Not yet sure how important that is, but I found a 4k7 pulldown resistor on the A+ connection of the relay board. The 4k7 resistor connected to B- leads to nothing an unpopulated resistor footprint. The chip itself seems to be a MAX485.

Biasing and termination resistors in a story factor with oscilloscope pictures:

http://support.fccps.cz/download/adv/frr/RS485/RS485.html