I’m trying to read the battery voltage using the built-in voltage divider attached to GPIO37. According the the Wireless Stick Lite schematic, GPIO37 connects to the voltage divider via what I think is a solder bridge labeled “BR1”. When I measure the resistance between GPIO37 and Vbat I get an open circuit, so it seems to me that BR1 is open. It should measure 220K Ohms.
I tested 3 different Wireless Stick Lite and all were open circuit. When I make the same measurement on my ESP32 LoRa OLED V2.1, I get 220K Ohms as expected. Both boards have the same voltage divider available to GPIO37, but only the Wireless Stick Lite has a solder bridge to GPIO37 shown on the schematic.
I have been able to read battery voltages successfully with the ESP LoRa OLED V2.1, so I know about the use of GPIO21 (Vext) and that it has to be LOW in order to take battery readings.
Can someone tell me how to solder BR1 closed? I can’t see it on the bottom of the board. Perhaps it’s on top under the can?