Wemos TTgo BEam

index.rst

@@ -37,6 +37,7 @@ Contents
   seeeduino_lorawan/README
   seeeduino_lorawan_gps/README
   all_on_one_rpi_node/README
+  wemos_ttgo_t-beam/README
 
 Indices and tables
 ++++++++++++++++++
@@ -45,5 +46,3 @@ Indices and tables
 * :ref:`search`
 
 .. * :ref:`modindex`
-
-

wemos_ttgo_t-beam/Arduino_Sketch_wemos_ttgo/Arduino_Sketch_wemos_ttgo.ino

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+No source code yet!

wemos_ttgo_t-beam/README.rst

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+Wemos TTGO T-Beam
+=================
+
+Hardware
+--------
+
+Micro-controller
+^^^^^^^^^^^^^^^^
+
+.. figure:: Wemos-TTGO-T-Beam.jpg
+  :width: 70 %
+  :align: center
+
+  `TTGO T-Beam <http://tinymicros.com/wiki/TTGO_T-Beam>`_ from Wemos. 
+  `TTGO T-Beam pinout <https://github.com/LilyGO/TTGO-T-Beam>`_, example code. 
+
+The `Wemos TTGO T-Beam <https://github.com/LilyGO/TTGO-T-Beam>`_ 
+is especially suited for mobile operations, because it has an 
+on-board battery holder for an 18650 lithium polymer (LiPo) 
+battery, a GPS receiver, a LoRa transceiver module (using the 
+LoRa chip SX1276) dedicated to the 868 MHz frequency band, and 
+an embedded battery charger. The module is operated by the 
+`Espressif ESP32 microcontroller <https://www.espressif.com/en/products/hardware/esp32/overview>`_ 
+board, which contains a dual-core Xtensa 32bit LX6 processor 
+running with up to 240MHz, 4 MB of flash memory (to store the 
+program code and some files within a file system), and 520 KB 
+of RAM (to store variables, status information, and buffers). 
+The ESP32 module also has built-in WiFi and Bluetooth LE 
+connectivity. In addition, the TTGO T-Beam has 4 MB of PSRAM 
+(pseudo static RAM) that is used as a memory extension for the 
+ESP32. The operating voltage of the board is 3.3V (this is 
+important when attaching sensors and other peripherals; they 
+also must operate on 3.3V). The board offers 18 general purpose 
+input/output pins (18 GPIOs), from which up to 12 can be used 
+as analog input pins (with 12bit analog digital converters 
+(ADC)) and one as analog output pin (8bit digital analog converter 
+(DAC)). Some GPIO pins can be used as serial port (programmable 
+Universal Asynchronous Receiver and Transmitter, UART), I2C port, 
+SPI port, and I2S port. The USB port is connected internally via 
+a USB/Serial converter to another serial port (UART). The WiFi 
+and Bluetooth antenna are mounted on the TTGO T-Beam board. A 
+small GPS antenna is connected via a pigtail to an U.FL / IPX 
+connector. The LoRa antenna has to be connected via an SMA-type 
+connector. The TTGO T-Beam is available from Chinese sellers 
+for around 23 € (I have not found a European shop where it 
+can be bought yet).
+
+The LoRa transmitter and receiver is encapsulated within a 
+LoRa module. It uses the LoRa chip SX1276 from the company 
+Semtech and is dedicated to the 868 MHz frequency band. The 
+LoRa module is connected via SPI interface to the microcontroller 
+and all of the required connections of the LoRa transceiver 
+pins with the microcontroller are already built-in on the TTGO 
+T-Beam board. Since the module only implements the LoRa physical 
+layer, the LoRaWAN protocol stack must be implemented in software 
+on the microcontroller. We are using the Arduino library LMIC 
+for that purpose (see below). The implemented LoRaWAN functionality 
+is compatible with LoRaWAN Class A/C.
+
+.. figure:: Wemos-TTGO-T-Beam_OLED2.jpg
+  :width: 70 %
+  :align: center
+
+  The Wemos TTGO T-Beam with a 2200 mAh 18650 lithium polymer 
+  (LiPo) battery (in the battery holder on the backside of the 
+  board) with attached OLED display.
+
+Sensor
+^^^^^^
+
+While the GPS module of the TTGO T-Beam is labelled as a uBlox 
+NEO-6 module, this does not seem to be true. The module seems 
+to be of a Chinese brand instead that is not fully compatible 
+with the uBlox NEO-6.
+
+The embedded `uBlox EVA 8M GPS <https://www.u-blox.com/en/product/eva-8m-sip>`_ 
+module is a standard precision GNSS receiver with 72 channels 
+supporting GPS and GLONASS. The module is capable to report up 
+to 18 positions per second (18 Hz). It is connected to the 
+microcontroller via I2C bus and supports different power saving 
+modes. A detailed explanation of the module is given in the 
+`uBlox EVA 8M datasheet <https://www.u-blox.com/sites/default/files/EVA-8M_DataSheet_%28UBX-16009928%29.pdf>`_.
+
+Display
+^^^^^^^
+
+We have attached a 0.96 in monochrome OLED display to the I2C 
+bus of the TTGO T-Beam module. The display is using an SD1306 
+controller and has a resolution of 64 x 64 pixels.
+
+Software
+--------
+
+The section is still to be written.
+
+Services
+--------
+
+The section is still to be written.
+
+Code files
+----------
+
+.. literalinclude:: Arduino_Sketch_wemos_ttgo/Arduino_Sketch_wemos_ttgo.ino
+   :language: arduino
+   :linenos:
+   :caption: Arduino Sketch for Wemos TTGO T-Beam sensor node
+   :name: Arduino_Sketch_wemos_ttgo.ino
+
+.. literalinclude:: TTN_Payload_Decode.js
+   :language: Javascript
+   :linenos:
+   :caption: TTN payload decoder for Wemos TTGO T-Beam sensor node
+   :name: TTN_Payload_Decoder_Seeeduino_wemos
+
+References
+----------
+
+- `Wemos TTGO T-Beam pinout, libraries, examples <https://github.com/LilyGO/TTGO-T-Beam>`_
+- `TTGO T-Beam TinyMicros Wiki (links to schematics, GPS datasheet) <http://tinymicros.com/wiki/TTGO_T-Beam>`_
+- `TTGO T-Beam – Kompakter Knochen zum Mappen <https://www.bjoerns-techblog.de/2018/10/ttgo-t-beam-kompakter-knochen-zum-mappen/>`_
+- `TTNMapper on the TTGO T-Beam <https://github.com/DeuxVis/Lora-TTNMapper-T-Beam>`_
+- `TTNMapper on the TTGO T-Beam with Deep Sleep <https://github.com/PiAir/Lora-TTNMapper-T-Beam>`_
+- `Wifi & BLE driven passenger flow metering with cheap ESP32 boards <https://github.com/cyberman54/ESP32-Paxcounter>`_

wemos_ttgo_t-beam/TTN_Payload_Decode.js

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+Yet to be written