ESP8266 Community Forum

- Sun Jul 23, 2017 4:01 pm #68474 I have a drone with a Pixhawk flight controller and 3DR telemetry radio which uses the mavlink protocol.

I want to use the ESP8266 to bridge the USB ground radio module to wifi using the esp in AP mode so I can connect to the esp on my phone or tablet or both and have access to the telemetry radio link.
The esp and radio module will be battery powered as a stand alone access point which I can place nearby, probably on the roof of the car,

I want to use the radio module rather than direct wifi because of the greater range available. Using direct wifi to the drone is almost unusable because of it's limited range.

I have found a great project called Mavbridge which has created an esp/wifi bridge for connecting directly to the drone but it has no details as to how to connect via a radio module.

I have also found this instructable which does connect to the radio module the way I intend but he uses an airborne radio module without the usb/ftdi chip. It looks like a great solution but since I only have the usb ground radio module available, I do not know how to connect it to the esp. It seems the difference between the airborne and ground modules is the addition of a usb plug and FT232RL ftdi chip.

I need to know how to connect the usb plug on the radio module to the esp to create the bridge using one of the above firmware solutions or something else that would achieve the same goal.

I hope I made some sense there.

Thanks in advance.

- Sun Jul 23, 2017 5:06 pm #68477 Provided I understand your question correctly (I really have no experience or knowledge whatsoever about flight controllers/MavLink/Telemetry):

The ESP itself doesn't "Talk" USB and the telemetry radio (receiver itself) module probably also doesn't.
Most likely the radio module uses normal RS232 (hopefully at 3.3V TTL levels) which is connected to an internal FTDI-chip.
If so, the best way of connecing the radio module to the ESP is by modifying the radio module, bypassing the FTDI-chip, and connecting its TX to the RX and its RX to the TX of the ESP.

Of course, this is all (my) theory, so you'll have to work things out yourself (maybe with some help of the radio module manufacturer or its forum).

After that, you'll need some firmware in the ESP that's able to chew the telemetry data into something useful for your phone or tablet (that info can be obtained here).

Assumption is the mother of all f*ckups. At least: that's what I'm assuming.

- Sun Jul 23, 2017 5:19 pm #68478

Provided I understand your question correctly (I really have no experience or knowledge whatsoever about flight controllers/MavLink/Telemetry):

The ESP itself doesn't "Talk" USB and the telemetry radio (receiver itself) module probably also doesn't.
Most likely the radio module uses normal RS232 (hopefully at 3.3V TTL levels) which is connected to an internal FTDI-chip.
If so, the best way of connecing the radio module to the ESP is by modifying the radio module, bypassing the FTDI-chip, and connecting its TX to the RX and its RX to the TX of the ESP.

Of course, this is all (my) theory, so you'll have to work things out yourself (maybe with some help of the radio module manufacturer or its forum).

After that, you'll need some firmware in the ESP that's able to chew the telemetry data into something useful for your phone or tablet (that info can be obtained here).

Thank you for your reply quickfix.
I think you are on the money with that response.

I have been looking at the data sheet for the ftdi chip and I think I can run a seperate cable out of the module from the Rx Tx of the ftdi chip and then I should be able to use one of the firmware options above to untangle the mavlink protocol.

I guess I was hoping to be able to simply have a usb socket attached to the esp so I could just plug in the radio module as required. Your solution will be almost as easy.

Thanks