LILYGO TTGO T-Call ESP32

All ESP32 boards running MicroPython.
Target audience: MicroPython users with an ESP32 board.
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jadro
Posts: 16
Joined: Wed Apr 29, 2020 7:02 pm

LILYGO TTGO T-Call ESP32

Post by jadro » Sat May 01, 2021 6:02 pm

Hi to all,

I have tested for a month the module I use, it is LILYGO TTGO T-Call ESP32.
I have last Micropython firmware. Last before this module works same...
I use it on USB power and it works great, CALLS, SMS Messages, incomming, outgoing... I put temperature sonde and it calls me when temp goes under or over min and max temperature, great... I have Battery too, and this is problem, when it starts and works on USB everithing is ok but when I disconnect USB adapter (5V 2A) from wall socket 220 V, it goes won with Battery power. Diode on the pin signals me that it works, code works. After connect it on USB again, it works as microcontroller but SIM module dont work anymore, it freezes the CALLS and SMSing but I know it works while my diodes constantly goes ON and OFF as I coded it. Then I disconnect power USB and BAttery and start it from USB again and then when he itialize, he send me those SMS that he has to send me when it was on Battery.
This module do not work on battery as espected, did someone have the same problems?

jadro
Posts: 16
Joined: Wed Apr 29, 2020 7:02 pm

Re: LILYGO TTGO T-Call ESP32

Post by jadro » Tue May 04, 2021 8:57 am

I think problem is in UART connection, I'am not familiar with it...
In code, there is initialization uart = UART(1, 9600, timeout=1000, rx=self.MODEM_TX_PIN, tx=self.MODEM_RX_PIN) where MODEM_TX_PIN = 26 and MODEM_RX_PIN = 27 and when on USB this is OK but what if battery is connected and USB power goes down? Will the battery power works normally as USB?

dan76
Posts: 2
Joined: Thu Jan 21, 2021 1:52 pm

Re: LILYGO TTGO T-Call ESP32

Post by dan76 » Tue May 11, 2021 5:38 pm

I had seen that SIM800L circuit requires a lot of current during initialization.

Is your battery delivering enough current ?

See https://github.com/Xinyuan-LilyGO/LilyG ... /issues/11

Kindly
Daniel

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