I am running an ESP-06E with SDK 1.4.0 and a modified AT Command parser due to some custom AT commands.
We configure our product by putting the unit into soft AP mode, then using a WIFI-enabled PC to send/receive test and config data via HTTP Post during production.
This works very well apart from some unusual behaviour which I will try and describe.
When in Soft AP mode, I can retrieve all the test data apart from the RSSI value (wifi_station_get_rssi()). When I request this value, I get 31 (Error).
HOWEVER, this is only the case for a freshly programmed (and unused) ESP module.
If the ESP module has previously connected to a WIFI router in Station mode (i.e. successfully completed AT+CWJAP), and is then subsequently put into soft AP mode, the RSSI value is correctly retrieved.
So in short: SoftAP mode RSSI request only works if the unit has previously connected to a router in station mode. It doesent matter if the power has been recycled, the unit appears to remember that it has (at least once) connected to a router successfully.
This is a major problem because it prevents us from testing the RSSI of the module, which would be connected to a test PC.
Any ideas?