Frequently Asked Questions
You only need at least two ducks, a papa duck and mama duck, to set-up a network. With two ducks, you can have a point to point network with the protocol with just 2 ducks. Adding more ducks will extend the network.
The cause of this error because the library, PubSubClient.h, is missing. To install the library, go to Sketch -> Include Library -> Manage Libraries. In the search box, type PubSub. Find and install PubSubClient by Nick O'Leary.
This issue occurred because when the program tried to compile, it came across two “Wifi.h” files and was not sure which one to choose. But this is a warning. It should not be an error. Read the whole error to see if there are other issues.
- ser_open(): can't open device "/dev/ttyACM0": Permission denied
- To fix this run the following commands via terminal $ sudo usermod -a -G dialout $ sudo chmod a+rw /dev/ttyACM0
- Replace username with your devices name & Replace /dev/ttyACM0 with your USB Port
- That can be found inside Arduino IDE via TOOLS > Port
This can happen if you are trying to upload to a T-Beam on macOS Big Sur. Try downloading the driver from this thread https://github.com/Xinyuan-LilyGO/LilyGo-T-Call-SIM800/issues/139.
Make sure that the LoRa board is connected to the computer using a DATA TRANSFER CABLE. Not all cables are created equal. One of the cables transfer data from computer to computer. The other cable just charges devices but cannot transfer/receive data. Make sure you are using a data transfer cable.
This can be a data packet size issue. Check to see if the PubSubClient library is up-to-date. If it is then go into the PubSubClient.h file and change the parameter value of MQTT_MAX_PACKET_SIZE, from 128 to 256. This increases the data capacity for MQTT. For more details, check this closed issue
Download and install the ESP32 exception decoder. This will help understand where the issue is coming from and make it easier for us to help you with issues. Instructions to install here: https://github.com/me-no-dev/EspExceptionDecoder.
