AT+CIUPDATE每次都失败是什么原因？

[chinaup]

snd:AT+CWMODE=3
brcv:OK
snd:AT+CWQAP
brcv:WIFI CONNECTED
brcv:WIFI GOT IP
brcv:WIFI DISCONNECT
brcv:OK
snd:AT+CWJAP="TP-LINK_E","12345678"
brcv:WIFI CONNECTED
brcv:WIFI GOT IP
brcv:OK
snd:AT+CIUPDATE?
brcv:+CIUPDATE:0
brcv:OK
snd:AT+CIUPDATE
brcv:+CIPUPDATE:1
brcv:+CIPUPDATE:2
brcv:ERROR

[esp-at]

只有发布的 AT 固件才能通过 AT+CIUPDATE 升级固件。
请参考文档：https://docs.espressif.com/projects/esp ... pdate.html