Blog – New Product – ESPrtk-BT 4.x.x – ESP32 RTK.

ESPrtk BT 4.x.x

A new product.

This is not an upgraded version of ESPrtk 3.x.x.

This is a special version and has many differences from ESPrtk 3.x.x.

It deserves to have a new name on our list.

It is ESPrtk-BT.

Most of ESPrtk 3.x.x Main Action programs do not appear on ESPrtk-BT.

The features that we introduce below are new and exclusive by the ESPrtk development team.

Most of ESPrtk 3.x.x Main Action programs do not appear on ESPrtk-BT.

However, nearly all the remaining features in WEB_Configure mode (like Ublox tab, Nasvpark, GNSS Viewer, System), UART_Configure and Hardware_Control of version 3.9.8 are included in ESPrtk-BT 4.x.x.

All resources of the ESP32 chip are fully exploited to focus on 2-way data flow processing for Bluetooth / WiFi TCP-UDP bridge.

With the ability to synchronize real-time commands on all 3 types of ports (UART0 – UART RTK – Bluetooth / WiFi):

  • Send GPIO control commands on ESPrtk from all 3 types of ports (UART0 – UART RTK – Bluetooth / WiFi).
  • Query the error status of ESPrtk on all 3 types of ports (UART0 – UART RTK – Bluetooth / WiFi).
  • Query the status, total bytes, and speed of each type of threaded message on all 3 types of ports (UART0 – UART RTK – Bluetooth / WiFi).
  • Control on / off each type of message running through TX-UART RTK stream and TX-Bluetooth / WiFi on all 3 types of ports (UART0 – UART RTK – Bluetooth / WiFi).
  • … and many more features, read the ESPrtk BT 4.x.x datasheet for more details.


Inherits all of IMU ESPrtk 3.9.8’s most powerful features, including automatic AI calibration.

On ESPrtk 3.9.8 IMU data can be export to TX_UART0 ports .

On ESPrtk-BT 4.X.X IMU data can be output to 3 types of ports (TX_UART0 – TX_UART RTK – TX_Bluetooth / WiFi) at the same time.

Along with that, IMU-Viewer and Calibration Helper tools on Web Configure make simulation, test and calibration be more simple and intuitive .

SD card.

Support filter and save data on both RX-UART RTK and RX-Bluetooth / WiFi streams.

You can set the cycle and choose any data type (NMEA / RTCM / STRAQ / UBX) along with any ID to save to SD card. In addition, on the GNSS Viewer interface, there is an additional button to save data to the SD card.

Stream data management.

On ESPrtk 3.9.8, It allow the user to configure filters to manage the RTK data stream running through it. Can insert data, remove a message, repeat a message, replace a message with other data, minimize the appearance of a message… and set a speed limit (highest) for Push-Out data.

This functionality is applicable on any RTCM / NMEA / SKYTRAQ / UBX message type running through TX_UART RTK stream, with up to 1500 bytes of raw Script text.

On ESPrtk BT 4.x.x, you can do the same thing for each type of message running on both TX_UART RTK and TX_Bluetooth / WiFi streams with up to 2700 bytes of raw Script text per stream.

UART to Bluetooth.

2-way bridge.

Supports 2 types of connection protocol Bluetooth Classic and Bluetooth BLE 4.2.


2-way bridge.

Support WiFi AP and STA.

TCP-UDP feature on ESPrtk 2.4.1 version is restored and stronger than ever with 6 types of connection protocols:

  • TCP Server AP.
  • TCP Server STA.
  • TCP Server Client.
  • UDP Server AP.
  • UDP Server STA.
  • UDP Server Client.



Bluetooth and WiFi are the same.

The only difference between these 2 types of connection is that the device that connects to the ESPrtk is either a Bluetooth device or a WiFi device.

All features (primary and secondary functions) for the Bluetooth-UART bridge are the same as WiFi-UART.


One-way data bridge.

Data received on the RX-UART RTK port will not be sent to the Bluetooth / WiFi device, but will be sent to the TX-UART RTK port.

Functions like IMU, SD, Stream management, … are also supported in this mode.

Functions support – Real-time multitasking.

Users can activate 11 different functions to run at the same time in real time on the ESPrtk-BT.


Actions FLAG


Transmit RX-UART-RTK data to TX-Bluetooth/WiFi device


Transmit RX-Bluetooth/WiFi data to TX_UART-RTK device


Export IMU Data to TX_UART_0 port


Send IMU_1 Data to Bluetooth/WiFi device


Send IMU_2 Data to Bluetooth/WiFi device


Export IMU_1 Data to TX_UART-RTK port


Export IMU_2 Data to TX_UART-RTK port


Save NMEA/RTCM/RAW/.. Data (on RX-UART-RTK) to SD Card


Save NMEA/RTCM/RAW/.. Data (on RX-Bluetooth/WiFi) to SD Card


Respond realtime command control on RX-UART-RTK


Respond realtime command control on RX-Bluetooth/WiFi

Configure by SCRIPT code.

You can only see this on our ESPrtk products !

The biggest change in the configuration of ESPrtk is the idea of ​​allowing users to configure the RTCM / NMEA / SKYTRAQ / UBX message filter using SCRIPT code. It will give the user the ability to filter any type of message they need.

On ESPrtk 3.9.8 it was applied to the Stream_Manager configuration .

On ESPrtk BT 4.x.x, configuration with SCRIPT code is applied on all features related to data stream. The configuration method using SCRIPT is easy to understand and concise. Examples for each are included in our datasheet and documentation.

Quality and Cost.

What we care most about is high quality, and the second thing we care about is low cost.

A high quality product does not mean the cost is not low.

Over the past 4 years, we have always strived to pursue a slogan that has attached to our brand ‘High quality RTK positioning solution with low cost ESP32’.

There’s more….

This article looks short, it is because the entire content of the post is focused on introducing new features.

Don’t forget, ESPrtk BT 4.xx inherits many features of ESPrtk 3.9.8, to have a complete look at ESPrtk BT 4.xx, please visit and learn about the features of ESPrtk 3.x.x at :

The most detailed and complete documentation is always the datasheet. It would be difficult to describe all hundreds of pages of documents on this single post. The datasheet versions will be updated here: ESPrtk documents

The firmware versions BT 4.x.x will be updated here:

And if the article is not enough for you, feel free to contact us and feel free to ask any questions : Contact us .

Special thanks to Jesse Joabe.

This project received special attention from Brazilian investor Jesse Joabe.

Jesse Joabe is a visionary of GNSS / RTK positioning technology, he contacted us and gave his ideas about ESPrtk BT, we finalized that idea and started working together to make that idea come true.

We also look forward to creating many new products with Jesse Joabe in the future.

He is also planning to use ESPrtk-BT in his new product. Please follow the official Facebook page – Protech Agro for the latest information on the upcoming product.

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