Cannot switch device to developer mode

Developers Nexi (Italy)
#1

I’ve bought a new Poynt Smart Terminal (P3303 V2.0) which has initially been configured in “production mode”, I wish to switch to “developer mode” but I cannot bind the device.

I’m running Ubuntu (18.04).

$ adb devices
List of devices attached
P6SW175JS000835	unauthorized

I’ve also followed with no success this guide https://developer.android.com/studio/run/device#setting-up

09/30 15:16:48: Launching app
$ adb push /tmp/MyApplication/app/build/outputs/apk/debug/app-debug.apk 
/data/local/tmp/com.example.lrkwz.myapplication
com.android.ddmlib.AdbCommandRejectedException: device unauthorized.
This adb server's $ADB_VENDOR_KEYS is not set
Try 'adb kill-server' if that seems wrong.
Otherwise check for a confirmation dialog on your device.
Error while Installing APK

Relevant environment info:

$ adb version  
Android Debug Bridge version 1.0.36
Revision 1:7.0.0+r33-2
$ groups
lrkwz adm cdrom sudo dip plugdev lpadmin sambashare docker
$ lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 18.04.1 LTS
Release:	18.04
Codename:	bionic
#2

Hi Luca,
The device needs to be unlocked before it can be used in developer mode
https://poynt.github.io/developer/setup/developer-mode.html#-poynt-smart-terminal-v2

Regards,
Deepak

#3

That is the problem.

  1. Put your device into fastboot mode by holding the power and developer button while the device is powered off. => OK

  2. Select Fastboot Protocol from the fastboot menu => OK

  3. Make sure you have the Android SDK tools installed on your computer => OK

  4. Run the command to initiate the developer mode process on Poynt Smart Terminal: fastboot flashing unlock => KO

    $ fastboot --version
    fastboot version 28.0.1-4986621
    Installed as /home/lrkwz/Android/Sdk/platform-tools/fastboot
    $ fastboot flashing unlock
    < waiting for any device >

The device is not listed in adb devices and the fastboot command is stuck.

#4

Resolved.

Is is matter of adding a /etc/dev/rules.d/ definition such as this 51-android.rules

SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", MODE="4e40", GROUP="plugdev" # Poynt

numeric id’s from lsusb