<rant-mode>
Continuing my rant from Big ESP32 + SX127x topic part 3 - #396 by bluejedi :
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In TTGO T-Beam V1.0 and V1.1 circuit diagrams all button switches are labeled “reset”!
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Since 2020 Q4 The TTGO T-Beam (V1.1) is available in two very different configurations:
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With SX127x LoRa module
This uses the original SX127x LoRa chip.
This will work with the MCCI LMIC LoRaWAN library. -
With SX1262 LoRa module
This uses the newer SX1262 LoRa chip.
This will NOT work with the MCCI LMIC LoRaWAN library
and requires a different LoRaWAN library with SX1262 support!
(MCCI LMIC currently does not support SX1262.)In all their ‘wisdom’ LilyGO decided to use the same name for both models:
TTGO T-Tbeam V1.1 (a.k.a. T22 V1.1).
So just the name and version are not enough to know anymore.
You will now in addition also need to know which of these different LoRa modules is mounted on the board. The only way to see the difference is the text “SX1262” on the label on the LoRa module. And don’t forget that there are also different versions for different regions (ISM band frequencies).
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</rant-mode>
Below is a correct overview of the button names and their function and how each is powered:
| Button switch name | Function | Powered by |
|---|---|---|
| SW4 | Reset | +3.3V |
| SW5 | User button, GPIO38 (active-low) | +3.3V |
| SW6 | Power | VSys |
Note my post above about the +3.3V line. It needs to be programmed/configured correctly before the +3.3V line will actually carry 3.3V. If the voltage is too low this may impact (prevent) proper operation of the board and the buttons powered via +3.3V.