Search for: Log In Register OpenSprinkler › Forums › Hardware Questions › OpenSprinkler › Will expansion board from v2.3 work in v3? This topic has 3 replies, 3 voices, and was last updated 1 month ago by Ray. Viewing 4 posts - 1 through 4 (of 4 total) Author Posts March 7, 2021 at 9:08 am #69378 SergeiParticipant Hi! I am thinking about buying a v3 controller to keep an extra just in case. Would an old expansion board from my v2.3 work with a new controller? Thanks, Sergei March 11, 2021 at 9:23 am #69414 RayKeymaster v3 controller only works with expander version 3, so unfortunately the previous expanders (2.x) will not work with v3 controller. August 12, 2021 at 9:21 pm #70897 RottenMuttParticipant Why the change? I bought off Amazon, wasn’t a choice for 2.X so I got the wrong one. How is addressing determined one v2? No jumper… August 22, 2021 at 6:19 pm #70964 RayKeymaster You can get all versions of expander from our website: https://opensprinkler.com/product/zone-expander/ On v2 there is no jumper for addressing because it uses shift register cascading, so the order of zones is completely determined by the order the expanders are linked. V3 uses I2C IO expanders because ESP8266 does not have enough GPIO pins to talk to shift registers and I2C is the most efficient way to support expanders using only 2 signal lines. Author Posts Viewing 4 posts - 1 through 4 (of 4 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In OpenSprinkler › Forums › Hardware Questions › OpenSprinkler › Will expansion board from v2.3 work in v3?