WiFi Telemetry with Cheap 3$ ESP8266

Hello all,

It's not a new achievement using wifi as Telemetry but this UART to WiFi module has really long range (up to 400 meters), and unbeatable price. Very small form factor (about 2cm x 1.5cm) and light (3 gr). Great for the small sized UAVs. And your Smart Phone or Tablet will become a GCS with no additional hardware. And with module's available GPIOs it's functionality can be increased (PWM, I2C sensors) you can drive LEDs or get sensor data over wifi.

Get firmware from https://github.com/jeelabs/esp-link > this is the stable solution for UART only

Another eriksl's great firmware for ESP8266 https://github.com/eriksl/esp8266-universal-io-bridge > A lot of functions supports pwm display temp sensors but UART bridge not stable, random drop outs

I've been experimenting with new ESP8266 UART to WiFi module and happy to announce you that it can be used as Telemetry module. It should work on all MAVlink devices that uses Serial communication. I tested with ESP-03 and APM 2.6 (3.2) and range is acceptable for Follow Me, or Guided missions. it works reliable enough and its really cheap, start as low as 2,5 $ at several stores (its a 3.3v device you will need a good (about 300ma) power source).  I think APM 2.6 users should receive at least a one last bug fix release (several reports indicates 3.2.1 has some issues with altitude calculations), of course you can compile your own verison.

releated fix 



For those who are interested, I can provide APM:Copter 3.2 (not 3.2.1) firmware with the fix. I am happy with it, doing some great auto flights, checking parameters, follow me flights, you can fly your UAV even without RC controller, directly from your wifi enabled GCS.

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  • @Kaan: check that baud rate of your APM matches what's configured in firmware (in web control panel). Also, web control panel shows sent/received packet counts- you can verify that firmware decodes packets from serial correctly).
    Another feature- add LED to one of GPIO pins (check which one in schematics in github). There are two pins which blink on received network/UART packets.
  • @festlv I tried your firmware with ESP-12E (nodemcu 1.0) however for some reason the esp board does not receive any serial packages. I uploaded another firmware to test RX/TX pins, they work fine. What can be the issue? I can send packets through PC --- > UDP -- > Serial --- > APM

    however cant get any packages

    APM --- > Serial ---> UDP ---- > PC (not working)

  • I've done a bit of prototyping with ESPs for Mavlink transmissions. I've found that UDP works best (reliable up to 921600 serial baud rate). In case anyone's interested, here is the source code of the firmware: https://github.com/festlv/mavbridge 

    A friend of mine also made a small batch of these modules- they are available on tindie: https://www.tindie.com/products/festlv/mavbridge/

    Serial MAVLink <> WiFi bridge running on ESP8266. Contribute to festlv/mavbridge development by creating an account on GitHub.
  • Solved.

    To set WiFi connection - USB cable should be unplugged even if PC and APM are not connected via COM-port.

    Tx/Rx are not available for any other connections except COM if USB-cable is plugged in PC and APM even if connection is not set through this channel.

  • Ping - OK, module is seen by PC.

    TX and RX cables aren't swapped around -  - checked, even tested by swapping.

    Telemetry port is set to 57600 - checked.

    UDP instead of TCP - no connection, waited for 10 minutes, no blue flashes of blue module LEDs

  • @ sergey 

    Try to use UDP instead of TCP.  Also try to Ping the module from your PC and se if you get any response. 

    Connect your APM via USB and make sure the telemetry port is set to 57600 

    If all this won't fix the issue, then make sure TX and RX cables aren't swapped around.  HK is known to do this kind of mistakes. 

  • Got this one from HK...

    Wireless Wifi Telemetry Module with Antenna for Pixhawk APM Flight ... 

    …and can not connect APM2.6 with Mission Planner (latest version) on my notebook PC (XP SP3) through WiFi.

    From the first view all is OK - PC connects with adapter through WiFi net, IP is correct matches noted on adapter. I set TCP protocol (as noted on adapter) in Mission Planner, set speed 57600, port and IP according to information on adapter’s backside, press connect and receive “No Heartbeats received” after 30 seconds of timeout.

    Could you please help me - where could be a mistake?

  • I only patched the Auto RTL triggering when GCS link disconnects. Alt Hold seems more precise with 3.2 firmware;

    This firmware compiled on Windows Machine with modified Arduino IDE provided from Ardupilot Project and just for Quads. Please use it with YOUR OWN RISK. I DOES NOT GIVE ANY GUARANTEE by ANY MEANING


  • @Omer, I wonder about your saying about some issues in altitude calculations in 3.2.1. I never get stable in altitude hold with 3.2.1.

    I am very interesting to try your fixed 3.2 firmware. Can you provide me? Does it have altitude calculations issues?

    Thank you.

  • ok I found out it needs a booster 

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