Boards and Pins

These boards have been successfully tested with ttn-esp32. The pin configuration is shown below.

ttgo LoRa32 868MHz v1 (SX1276, with and without display)

The version 1 can be recognized by the metal WiFi antenna along the pins.

PIN configuration

#define TTN_SPI_HOST      HSPI_HOST
#define TTN_SPI_DMA_CHAN  1
#define TTN_PIN_SPI_SCLK  5
#define TTN_PIN_SPI_MOSI  27
#define TTN_PIN_SPI_MISO  19
#define TTN_PIN_NSS       18
#define TTN_PIN_RXTX      TTN_NOT_CONNECTED
#define TTN_PIN_RST       14
#define TTN_PIN_DIO0      26
#define TTN_PIN_DIO1      33

menuconfig

The default TTN values should work fine:

• TTN radio chip: Semtech SX1276 / SX1277 / SX1278 / SX1279
• SPI frequency: 10,000,000 (10 MHz)

However, these boards usually have a XTAL frequency of 26 MHz (instead of the default 40 MHz). The correct XTAL frequency can be found on the oscillator chip on the back of the board between the pins 19 and SRT (a magnifying glass will be helpful). It needs to be set with menuconfig at Component config / ESP-32 specific / Main XTAL frequency

ttgo LoRa32 868MHz v2 (SX1276, with and without display)

Not verified yet / image to follow

PIN configuration

#define TTN_SPI_HOST      HSPI_HOST
#define TTN_SPI_DMA_CHAN  1
#define TTN_PIN_SPI_SCLK  5
#define TTN_PIN_SPI_MOSI  27
#define TTN_PIN_SPI_MISO  19
#define TTN_PIN_NSS       18
#define TTN_PIN_RXTX      TTN_NOT_CONNECTED
#define TTN_PIN_RST       TTN_NOT_CONNECTED
#define TTN_PIN_DIO0      26
#define TTN_PIN_DIO1      33

Note: The DIO1 pin of the SX127x chip must be manually wired to pin 33 of the ESP32. Otherwise it will not work.

menuconfig

The default values should work fine:

• TTN radio chip: Semtech SX1276 / SX1277 / SX1278 / SX1279
• SPI frequency: 10,000,000 (10 MHz)

ttgo LoRa32 868MHz v2.1 (SX1276, with display)

The below information has been verified with a board that was marked: T3_V1.5 20180523. Other versions of the v2.1 boards seem to exist. Also note that the RST pin of the shielded LoRa module (third one from top left) is not connected.

The v2.1 boards can be recognized by the bigger SMA antenna connector (instead of the tiny U.FL/IPX connector).

PIN configuration

#define TTN_SPI_HOST      HSPI_HOST
#define TTN_SPI_DMA_CHAN  1
#define TTN_PIN_SPI_SCLK  5
#define TTN_PIN_SPI_MOSI  27
#define TTN_PIN_SPI_MISO  19
#define TTN_PIN_NSS       18
#define TTN_PIN_RXTX      TTN_NOT_CONNECTED
#define TTN_PIN_RST       TTN_NOT_CONNECTED
#define TTN_PIN_DIO0      26
#define TTN_PIN_DIO1      33

menuconfig

The default values should work fine:

• TTN radio chip: Semtech SX1276 / SX1277 / SX1278 / SX1279
• SPI frequency: 10,000,000 (10 MHz)