Firmware update issue "upload failed dfu device disconnected"

[espruino-discuss]

Posted at 2017-04-12 by reynish

I'm having difficulty updating the firmware on my puckjs. Once in DFUTarg mode;

• if i try to upload the firmware in NRF Toolbox i get the message "upload failed dfu device disconnected"
• if i try try to do it using NRF Connect, when I select the device I get a connecting spinner and never get the DFU icon in the menubar shown here https://www.youtube.com/watch?v=N3CJbl29vy0

Any ideas?

[gfwilliams]

Posted at 2017-04-18 by @gfwilliams

Have you tried a fresh battery? The DFU update uses quite a lot of power, so if your battery is on the way out then the DFU process can cause the battery voltage to drop too low, which will make Puck.js reboot

[espruino-discuss]

Posted at 2017-04-18 by reynish

Thanks Gordon,

I left the battery out over the weekend and when I tried updating it today it worked first time.

[gfwilliams]

Posted at 2017-04-18 by @gfwilliams

Great! It'd be worth checking 'Puck.getBatteryPercentage()` to get an idea how full it is - if it's running right down then stuff like the Magnetometer might not work.