Can someone please tell me what the J4 and P2 connectors are used for?
P2 is used to charge the battery with an external solar panel.
J4 is the antenna welding point of LoRa.
Hi fboesche,P2 is as discribe as Zhuqi ,J4 is a backup connector of GPS antenna.
Thanks for the correction of hairuitao.
Can you provide info with regards the solar panel? Max voltage?
Hello @hairuitao , can you provide the solar panel information?
Excelent! Many thanks ZhuQI
Thank you, then is confirmed that J4 is for GPS antenna.
Can you help @hairuitao ?
If you want to use solar panel, you need to add a Zener diode on D5 and solder a 5V solar panel to P2.