Led not working anymore with TTGO T-Beam V1.0


I’ve bought 3 TTGO T-Beam V1.0

At the begining, blue LED was on while plugged on USB or with a battery.
Now, 2/3 devices don’t have the LED on anymore

They are working, just no sign at all.

Samething with the flashing red LED, doesn’t flash anymore.

It is hard to guess if the radio still powered, or is it my bluetooth connection that is failing.

Is it a common problem ?

hmm - the LED is supposed to blink once a second if the device is awake and once every 30 seconds (used to be 5, but I just changed it to save CPU power) if the device is asleep.

the red led is controlled directly by the GPS chip (no software control) and indicates the GPS has a lock. If you are inside it is quite likely it won’t be able to keep a lock (though sometimes you luck out)

1 Like

It may be related, the terminal display no UBLOX GPS found, hoping that NEMA might work

Hbooted, wake cause 0 (boot count 1), reset_reason=reset
No I2C devices found
Meshtastic swver=0.7.4, hwver=1.0-US
Setting random seed 2128126070
Read RTC time as 0 (cur millis 64) valid=0
ERROR: No UBLOX GPS found, hoping that NEMA might work

The device stayed outside all the day

hmm - so the blue led doesn’t light at all? that’s not good because we definitely blink it in sw. And the red led is off also - even after sitting outside?

oh actually , can you triple check that you programmed the correct ROM?

Because “No I2C devices found” means that something is seriously busted - either the ROM is not for that board (i.e. you put on a TTGO-LORA-32 when you should have a TTGO_TBEAM) or something electrically has broken wrt the AXP192 power management chip they have on the board. That chip provides the power to the GPS and it handles controlling the blue LED. When we probed the i2c bus we should find the screen and the axp192.

firmware-ttgo-lora32-v1-US-0.7.4.bin :astonished:

1 Like

oh yeah - that’s not right. :slight_smile:

That was a wrong ROM, now the led works again.

Since the description of the item I bought was:

TTGO T-Beam ESP32 433/868/915Mhz WiFi Wireless Bluetooth Module ESP 32 GPS NEO-6M SMA LORA 32 18650 Battery Holder With OLED

I take the first match I saw:


Thank you

1 Like

yeah - ttgo has crummy naming - they also sell a “ttgo-lora32”. Lots of people have made this mistake - I’m thinking we might want to change the name for the lora32 build name to ttgo-32? to get lora out of it

Or maybe detect that the wrong rom has been installed and show a warning message

Or possibly just a wiki page on how to identify your hardware. (Maybe that already exists, I don’t know lol)

It is confusing for someone who has never done any of this before. My t-beams say “Modle: LORA32” on them.

1 Like

alas - that’s hard, because the LORA32 does look like a TBEAM without that extra stuff. So the ROM didn’t have any way to know things were missing :wink:

I’ve talked to TTGO about future products and encouraged them to stuff ID resistors or burn some CPU fuse bits to make this less painful :wink:

thanks - there is a wiki page, but we should make it more prominent.

If anyone wants to submit a PR to that adds a big warning on “check if your board is a TBEAM and if so make sure use ROM x not ROM y.” that would be highly appreciated.