Unable to connect to Tello from the Raspberry Pi

[harris-tweed]

Hello
First of all thank you for sharing clear set-up instructions for this project!
I completed all the steps and when trying python3 start.py I get the below result:

Tello: 21:35:12.380:  Info: start video thread
Tello: 21:35:12.381:  Info: send connection request (cmd="conn_req:9617")
Tello: 21:35:12.386:  Info: state transit State::disconnected -> State::connecting
Tello: 21:35:12.391:  Info: video receive buffer size = 327680
INFO:root:Initial telemetry sent...
Tello: 21:35:14.381:  Info: send connection request (cmd="conn_req:9617")
Tello: 21:35:16.387:  Info: send connection request (cmd="conn_req:9617")
Tello: 21:35:18.393:  Info: send connection request (cmd="conn_req:9617")
...

The ifconfig command gives me the below result for wlan1:

wlan1: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether 1c:bf:ce:1a:c6:79  txqueuelen 1000  (Ethernet)
        RX packets 15  bytes 1695 (1.6 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 15  bytes 2325 (2.2 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

It seems there should be an inet IP address for this command which I don't see here. I tried reseting the wlan1 with sudo dhclient -v wlan1 but this did not solve the issue:

The lsusb command seems to properly show a wireless adapter, giving the below when the wifi dongle is plugged in:

Bus 001 Device 002: ID 148f:5370 Ralink Technology, Corp. RT5370 Wireless Adapter
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

and the below when unplugged:
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Do you have any advice on how to root cause the issue?

[erviveksoni]

I used to face similar behavior while working on this project but for me that was due to the auto turnoff feature of Tello (power-saving). Sometimes RP was not able to acquire Tello IP address because by the time RP was on Tello was off.
So I used to ensure that Tello was switched on at the same time RP was booting up. Alternatively, when both were on reset the wlan1 (sudo dhclient -v wlan1).

I hope u must have tried the above steps already but just to reconfirm?

[harris-tweed]

Thank you Vivek for the quick reply, I have retried these steps but still encounter the same error.
The sudo dhclient -v wlan1 command gives the below answer:

Listening on LPF/wlan1/1c:bf:ce:1a:c6:79
Sending on   LPF/wlan1/1c:bf:ce:1a:c6:79
Sending on   Socket/fallback
DHCPDISCOVER on wlan1 to 255.255.255.255 port 67 interval 7
DHCPDISCOVER on wlan1 to 255.255.255.255 port 67 interval 13
...

I double checked wifi SSID and password in the /etc/network/interfaces file. I see the Tello wifi network appear on my other devices (MacBook, iPhone).

Do you have any recommendation on how to troubleshoot this? Can I get more verbose logs to understand where the RP -> Tello connection fails?