Firefly Nano remote

ESK8 Electronics
82

Great to see some development on the ESP32 boards :slight_smile: thank you very much @DroidSector for your development work

also looks interesting, but i still think the ESP with integrated Oled is superior in availability and Price. If some of you are curious here is a English documentation of the board: http://dl.intoyun.com/terminal/modules/datasheets/en/IntoRobot-Ant_Datasheet_en.pdf

83

TTGO boards have the same design for all frequencies, I think. It’s just an appropriate frequency in the code needs to be set. That 2.4ghz sx1280 chip looks great, but I’ll wait for a cheap board with OLED screen.

Just implemented the parallel processing in both cores of the ESP board, so screen updates won’t delay the radio transmission, which is 11ms for tx + rx.

Remote:

  • Core 1:
    • Handle buttons
    • Update display
  • Core 0:
    • Calculate throttle position
    • Transmit/receive data

Receiver:

  • Core 1:
    • Get telemetry
    • Update display
  • Core 0:
    • Receive/transmit data
    • Control speed
3 Likes
84

Sorry but maybe I understood something wrong… but u has two cores in the TTGO boards?? Two different cores, one for display handling and the other core for telemetry and the work parallel??

GREAT WORK!

85

Yes, and it’s rather easy to use:

86

Very nice! Makes the timing part very easy! Cool feature of the ESP Chip. Unfortunately not available for the SAMD chip! And maybe not necessary but as I said before… makes a lot things easier! U removed the 10ms transmitting time completely! Nice work!

87

The description of the feather made me think there are 2 chips for the 2 frequencies:

This is the 900 MHz radio version, which can be used for either 868MHz or 915MHz transmission/reception - the exact radio frequency is determined when you load the software since it can be tuned around dynamically. We also sell a 433MHz version of the same radio chipset! (from adafruit website)

88

Yeah, the same with TTGO boards. But their physical size is the same.

It’s possible to get SX1280 transceiver and use it with a WiFi LoRa board to make a universal remote, but I can’t find Arduino library to interact with it yet.

89

Turns out this board is almost exactly the same size as a battery meter in Ownboard ESC case, so I printed a new case for the receiver and added the software battery meter:

4 Likes
90

Good stuff man. Also doing a build with feathers It’ll probably take a month to get all the small stuff from china though.

91

So the parts list does not list a separate antenna. Is the default antenna just a regular wire of 7.8 cm?
And if I were to get this https://www.getfpv.com/tbs-xf-race-antenna-915mhz.html race antenna mentioned in the thread would it fit inside the remote housing easily?

92

I’m still waiting on a few parts. I have the antennas already and my case printed. The antenna is pretty small and flat, looks like it should fit no prob. I’ll mock some parts up later to double check.

93

Probably the same antenna: https://www.aliexpress.com/item/RCmall-868MHz-915MHz-FPC-Antenna-868MHz-Spring-IPX-IPEX-1-13-Antenna-IPEX-Antenna-850-1850MHz/32862215507.html. It will fit, just make sure to use 28-30 AWG wire because there is not much space between Feather board and OLED screen.

Finally tested TTGO boards in ~30 km group ride with more than 20 people, worked perfectly.

The only problem is that I got an older version without a battery probe. Now I’m waiting for this one, most probably will use in the final product:

Will test this one as well for the receiver side, will save you $10 if you don’t need/want a battery meter display on the skateboard:

94

Nice!

isn’t the SMA antenna mount on this one kind large and get in the way?

Edit, never mind I see it also has the small style antenna mount. :grinning:

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95

Yeah, the big one will need to be removed I guess.

96

I haven’t really been able to follow all the talk in this thread lately. Please understand this post as a desire to understand the remote design you’ve done.

If yes to the following question you can skip the last part :blush: Are you using the Bluetooth or or Wifi options on the TTGO for the remote control?

If no, are you using the LoraWAN protocol for the remote controls? LoraWAN is designed for an IoT wide area network and is from what I understand not really ment for this kind of application. LoraWAN is a competitor to among others SigFox, NB-iot and Lte-m. I believe some of the design goals of this protocol are long range (in terms of sensitivity), low power (devices on battery holding several years), low bandwidth (long interval and or few bytes which is also relevant for the low power) and many devices on the same bandwidth. I could be wrong, but there should be other technologies better suited?

97

I’m not using LoraWAN protocol, only LoRa radio in a fast mode. Basically, we need a board with a radio transceiver, a battery charger, and screen to make the assembly easier, so if anyone can recommend a more suitable board in $15-25 range I’ll test it as well.

98

Just ordered LM3UU linear bearings for testing, at 3x7x10mm one should fit right inside the throttle wheel.

99

Interesting. What tx-power and frequency band are you using?

100

I’ve set the frequency to 920 MHz and used these settings:

LoRa.setSignalBandwidth(500E3);
LoRa.setTxPower(10);  
LoRa.setSpreadingFactor(6);
LoRa.enableCrc();
101

maybe i misunderstand. but those bearings are linear. the are supposed to go along an axle. Not rotate around it. so if i understand your intention correctly. those lm3uu bearing will not work .

I use ptfe tube as a bushing in my remote wheel. it works great. it sits on a small 2mm carbon rod.

2 Likes