Reading SBUS2 sensor data to serial monitor

[i3dm]

Hello,

is it possible to use this lib to read SBUS2 sensor data to Serial monitor / PC? o create a sort of sensor data sniffer. i have an application where i like to take existing sensors data (sbus2) and display it on a PC. for this purpose i have some ESP32 and arduino boards i can use.

thanks.

[BrushlessPower]

Hello, the library doesn't have functions for sniffing SBUS2 Sensor Data. I'am not sure if stand alone Sensors will send any SSensor Data without SBUS Frame?!

But it should be possible if you are using a Futaba SBUS2 RX You have two options:

1. Using normal Serial.read() to read all Bytes in loop() and decode them with the help of this library. That would be the fastest to get the Sensor Data. But it would use a lot of CPU time (no Problem with ESP32 and 2 Cores)

2. you could change my library.

• disable Transmit and transmit Timer
• change USART RX Interrupt to receive (and decode) Sensor Data
• implement some "sensorGet"() functions That would be the smartest way and i could integrate it to the library.

If you want to use the Sensors stand alone, it will be more complicated. Because you have to Send SBUS Frame and Receive the Sensor Data.

If you have any questions, please contact me here.

[i3dm]

what i would like the board to do is to poll the SBUS2, read data from attached sensor, and then print it to serial monitor. Option #2 sounds like what i need but it is out of my reach to perform the necessary modifications to the lib - would you be willing to assist in that and add a "SensorGet" function?

Second option would be to have a futaba Rx on the line to poll the Sbus2 and the board will only sniff the line and decode sensors data. thanks.

[BrushlessPower]

So you want to use a Futaba Sensor without Futaba RX.

The problem is, that this library is not made for sending SBUS(2) Frames. It's possible but there will be many changes in API. The changes for reading other Sensors would be easy i think. That could be a nice Feature for this library.

But i have no spare time to do all these changes and test.

If you would use a Futaba RX you will have another Problem -> Without a Futaba TX the RX wont transmit any SBUS(2) Frames. So....thats no Solution. Mayby you could use the Bolderflight SBUS Library to transmit SBUS(2) Frames and just use another Serial for receiving?

The main Question for me: Why you want to use Futaba Sensors?

[i3dm]

I occasionally have sensors that need to be tested on the ground, for now i just do it with a futaba Tx and Rx but i wanted to find a stand alone solution for testing them without an actual radio.

[BrushlessPower]

ok, thats a good reason.

i could try to implement a function to get the raw Bytes on the Telemetry Slots

Slot = SBUS2_get_slot_data( 2 ) // get Second Slot Data

But you would have to calculate the Sensor Value from the Raw Slot bytes (sometimes from multiple Slots) That means, that i have to make get functions for every Sensor supported in this Library That is a lot of work.

[i3dm]

calculating should not be an issue, as on ground testing i can control the sensors physical input :) if you could add that, it would be really great!

why do you need a function for every sensor if you're getting raw bytes from a slot?

[BrushlessPower]

The Sensor Values are separated in Slots. Every Slot has 2 Bytes of Data

A Temperature Sensor needs 2 Slots A GPS Sensor needs 8 Slots So you need to know which Sensor starts on which Slot and how many Slots are used for that type of Sensor

My Library calculate the Slot Bytes for every supported Sensor (every Sensor is calculated different)

For your use Case you need to reverse all my calculations. You can see the calculation in SBUS2.cpp

[i3dm]

thats fine, i can calculate myself. for now i only need the function:

slot_val = GetSlotData(SlotNum);

[BrushlessPower]

ok, i will try to do it this week and will upload it

just to be clear: you will use ESP32?

[i3dm]

thats very nice of you. thank you. i can also use an aduino with an inverter but i should have some ESP boards at home so i think i will go for those. just need to figure out how to run them with Arduino IDE (first time using ESP32).

BTW will you also be able to include an example in the lib to read a sensor value?

[BrushlessPower]

ESP32 would be much easier for me, because i have the Serial for Debugging (and you will need it too)

Arduino with ESP32 is very easy. You just have to install ESP32 Hardware Library (Version 1.0.6)

i think i will upload my test Sketch directly to Github Master without Release

[i3dm]

sounds good. let me know when i can test it. will you also return a flag is sensor data exists on a certain slot? thats useful too

[BrushlessPower]

so i was able to change the library to save the Raw Telemetry Data to a buffer

actual i'am just print that buffer on Serial here is the output (in Hex) of that buffer:

0 0 0 3 C4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 23 4 D2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 83 64 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 A3 3A 98 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C3 49 29 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Slot ID's 0x03 -> RX Voltage on SLOT 0 0x23 -> Current Sensor on SLOT 4 (starting with Slot3) 0x83 -> RPM Sensor on SLOT1 0xA3 -> Current Sensor on SLOT 5 (starting with Slot3) 0xC3 -> Current Sensor on SLOT 3 (starting with Slot3)

now i will implement the get function

[BrushlessPower]

SBUS2.zip

So here is a very first Solution. The Example sends RPM on Slot1 with 600RPM and Read it back

you should be able to reduce that sketch down to your needs and read your Slot Data

[i3dm]

i will test it on ESP32 and report back. should i jumper G25 to G26 pins for the example to work?

btw - may i have your email for correspondence as well?

[BrushlessPower]

you can use every GPIO pin for RX and TX

in the Example i have used 25 and 26. And GPIO 16 is used for Oscilloscope to see the USART Interrupt

you have to use a Futaba RX with SBUS2 and an active Radio SBUS(2) Wire to RX (IO25) and 1k Resistor from TX (IO26) to SBUS(2) Wire

email: brushlesspower(at)protonmail.com

[i3dm]

the purpose of the device i need is to be able to test the sensors without a working Futaba Tx (i dont mind the Rx). will this be possible somehow?

also sent you an email. thanks.

[BrushlessPower]

you cant run it without active TX. Futaba RX (R7003 and R7008) doesn't send SBUS Frames until the TX is active. When you switch off the TX, the SBUS Frame is still send, but with active Failsafe Flag.

So if you power your RX 24/7 you don't need a TX (just for the first startup)

[i3dm]

the solution im trying to achieve is that the ESP32 will poll the SBUS2 sensors just like the Rx does, and my sensor will answer. then the data read back on ESP32 will be printed to serial monitor.

[BrushlessPower]

what you could do on Serial1 -> Debugging on Serial2 -> My SBUS2 Library on Serial3 ->Bolderflight SBUS Library for sending SBUS Frames (no idea if it will will work or if they can send SBUS2 Frames)

But it should be possible

Also you could just send SBUS2 Frames with Serial.write(sbus2[], Framelength); at 100.000Baud the Servovalues doesnt have to make sense

[i3dm]

Also you could just send SBUS2 Frames with Serial.write(sbus2[], Framelength); at 100.000Baud the Servovalues doesnt have to make sense

does your lib support this?

[BrushlessPower]

does your lib support this?

No. Because every Transmit (Telemetry Data) is controlled by Timer Interrupt. It could be possible to change it.....but i'am not sure how to do it. Futaba SBUS2 has very hard Timings. No idea what happens when Frames are not send correctly

So an easy way would be another Serial.

[i3dm]

any chance to get an example from you that sends sbus2 frames to poll the sensors via serial print?

that way i can even use 2 ESP32. one for polling the sensors and one for sniffing the data bqck to the serial monitor.

thanks. Lior.

Get Outlook for Androidhttps://aka.ms/AAb9ysg

---

From: BrushlessPower @.> Sent: Wednesday, July 21, 2021 2:30:15 PM To: BrushlessPower/SBUS2-Telemetry @.> Cc: i3dm @.>; Author @.> Subject: Re: [BrushlessPower/SBUS2-Telemetry] Reading SBUS2 sensor data to serial monitor (#36)

you cant run it without active TX. Futaba RX (R7003 and R7008) doesn't send SBUS Frames until the TX is active. When you switch off the TX, the SBUS Frame is still send, but with active Failsafe Flag.

So if you power your RX 24/7 you don't need a TX (just for the first startup)

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHubhttps://github.com/BrushlessPower/SBUS2-Telemetry/issues/36#issuecomment-884118344, or unsubscribehttps://github.com/notifications/unsubscribe-auth/ACENUTH6DT7RM7GKF5M3ROTTY2VUPANCNFSM5AR5S45A.

[BrushlessPower]

i have no example

SBUS is documented. You just have to search for it Boldeflights SBUS Library is doing exactly what you want and gives many informations.

its an easy thing

if you want me to build a plug and play system i can make you an offer.

[emilverwoerd]

Was reading this post and also want something like this. Want to add some additional sensors to this library. Like the hobbywing protocol so want to sniff it with an Y-cable. Between the original sensor and receiver

[BrushlessPower]

hi @emilverwoerd,

with the master branch it is already possible (with ESP32). See this Example: https://github.com/BrushlessPower/SBUS2-Telemetry/blob/master/examples/SBUS2_Read_Telemetry/SBUS2_Read_Telemetry.ino

If you are sniffing Sensors please post your findings here. I can help you with decoding or add the Sensors to the Library

[ericlangel]

@emilverwoerd any news?

[emilverwoerd]

Hi @ericlangel the code to sniff the package works great. I managed to send telemetry for the following sensors:

• Scorpion ESC
• Kontronik ESC
• (note that these are actually the same)

These sensors however are only on the more advanced transmitters. Currently I'm waiting for the hobbywing sensor which is in te latest firmware and than I can add that to.

Just finished this week since I hadn't a spare ESP32 laying around

[ericlangel]

nice to know

could you share the Code for sending Scorpion/Kontronik Telemetry?

[emilverwoerd]

I will do it later today