First of all: the product (V2.2) worked as described. soon I had to replace the double sided tape holding the battery case. 5 month after inserting it into my plant I had to repot it and during that action I would glue battery case, which came off again. I took it out of soil, cleaned it with water and recognized some blisters near the border of the sensor part. Then I glued the battery holder. While drying a lot of the green coating of the board by the soil stick came off!
now the product is unusable, because I will not poison the plant with copper. sad, I could not upload fotos proving that demage.
I think the whole sensor part should be sealed with lacqeur befor adding the parts.
update on 2017.07.17: It seems that I had wrong estimations, hoped that the shop would replace me that item. But nothing happend! That's a very bad experience about that product & store.
Response from AprilBrother | Jan. 28, 2018
Sorry about your sad story. We'll send a replacement board to you. Please contact us with message in Tindie.
Haven't been able to re-flash the moisture sensor with my own firmware. The instructions are incomplete or just plain don't work. Do I need to manually pull GPIO0 low or is there a button/switch I can use? No matter what I do with the jumper and button on the board I can't get it to enter bootstrap mode.
As a result I haven't been able to get the sensor to work at all.
Response from AprilBrother | Nov. 16, 2016
Did you remove the jumper for GPIO16 first? The jumper is used for deep sleep. You can find a note about "remove the jumper first before upload firmware" at our wiki. You can also contact us at our support forum. http://bbs.aprbrother.com/c/wifi