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Let's connect Roblox to The Things Network (the public LoRa network)... And create an IoT Digital Twin for real-world objects...
What's a "Digital Twin"? It's a Virtual Object that mirrors a Real-World Object through Sensors and Actuators.
In Roblox we shall call the HTTP + JSON API...
https://developer.roblox.com/en-us/api-reference/class/HttpService
To access the Live Sensor Data at The Things Network...
https://www.thethingsindustries.com/docs/integrations/storage/retrieve/
This will be useful for educating kids about IoT, by creating digital mirrors of real-world objects.
More about The Things Network...
The Things Network exposes an API (HTTP GET) to fetch the Uplink Messages transmitted by our IoT Device...
https://www.thethingsindustries.com/docs/integrations/storage/retrieve/
Here's the command to fetch the latest Uplink Message...
curl \
-G "https://au1.cloud.thethings.network/api/v3/as/applications/$YOUR_APPLICATION_ID/packages/storage/uplink_message" \
-H "Authorization: Bearer $YOUR_API_KEY" \
-H "Accept: text/event-stream" \
-d "limit=1" \
-d "order=-received_at"Which returns...
{
"result": {
"end_device_ids": {
"device_id": "eui-YOUR_DEVICE_EUI",
"application_ids": {
"application_id": "luppy-application"
},
"dev_eui": "YOUR_DEVICE_EUI",
"dev_addr": "YOUR_DEVICE_ADDR"
},
"received_at": "2021-10-02T12:10:54.594006440Z",
"uplink_message": {
"f_port": 2,
"f_cnt": 3,
"frm_payload": "omF0GQTUYWwZCSs=",
"rx_metadata": [
{
"gateway_ids": {
"gateway_id": "luppy-wisgate-rak7248",
"eui": "YOUR_GATEWAY_EUI"
},
"time": "2021-10-02T13:04:34.552513Z",
"timestamp": 3576406949,
"rssi": -53,
"channel_rssi": -53,
"snr": 12.2,
"location": {
"latitude": 1.27125,
"longitude": 103.80795,
"altitude": 70,
"source": "SOURCE_REGISTRY"
},
"channel_index": 4
}
],
"settings": {
"data_rate": {
"lora": {
"bandwidth": 125000,
"spreading_factor": 10
}
},
"data_rate_index": 2,
"coding_rate": "4/5",
"frequency": "922600000",
"timestamp": 3576406949,
"time": "2021-10-02T13:04:34.552513Z"
},
"received_at": "2021-10-02T12:10:54.385972437Z",
"consumed_airtime": "0.370688s",
"network_ids": {
"net_id": "000013",
"tenant_id": "ttn",
"cluster_id": "ttn-au1"
}
}
}
}result.uplink_message.frm_payload contains the Sensor Data that we need, encoded with Base64 and CBOR...
"frm_payload": "omF0GQTUYWwZCSs="Our Sensor Data is encoded with CBOR to keep the LoRa Packets small (max 12 bytes), due to the Fair Use Policy of The Things Network...
More about CBOR Encoding...
Roblox provides a Lua Scripting API that fetches External HTTP URLs (GET and POST)
https://developer.roblox.com/en-us/api-reference/class/HttpService
Here's how we call it to fetch the Sensor Data from The Things Network...
Enable HTTP Requests: Click Home -> Game Settings -> Security -> Allow HTTP Requests
Under Workspace, create a Part.
Under the Part, create a Script.
Copy and paste the script from DigitalTwin.lua
Follow the steps in the next section to copy and paste the ModuleScripts for Base64 and Cbor
To fetch the Sensor Data from The Things Network, we call getSensorData in DigitalTwin.lua
When we run this Roblox Script...
-- Fetch the Sensor Data from The Things Network (LoRa)
local sensorData = getSensorData()
-- Show the Temperature
if sensorData then
print("Temperature:")
print(sensorData.t)
else
print("Failed to get sensor data")
endWe should see the Temperature Sensor Data fetched from The Things Network...
Temperature:
1236
Under ServerStorage, create two ModuleScripts: Base64 and Cbor.
Copy and paste the ModuleScripts from...
(Yep they need to be ModuleScripts. Normal Scripts won't work)
To test Base64 and CBOR Decoding...
-- Load the Base64 and CBOR ModuleScripts from ServerStorage
local ServerStorage = game:GetService("ServerStorage")
local base64 = require(ServerStorage.Base64)
local cbor = require(ServerStorage.Cbor)
-- Base64 Decode the Message Payload
payload = base64.decode('omF0GQTUYWwZCSs=')
print("payload:")
print(payload)
-- Decode the CBOR Map
sensorData = cbor.decode(payload)
print("sensorData:")
print(sensorData)We should see...
payload:
�at���al�
sensorData:
{
["l"] = 2347,
["t"] = 1236
}
The ModuleScripts were copied from...
https://github.com/iskolbin/lbase64/blob/master/base64.lua
https://github.com/Zash/lua-cbor/blob/master/cbor.lua
This line in base64.lua was changed from...
local extract = _G.bit32 and _G.bit32.extractTo...
local extract = bit32 and bit32.extractLet's use a Roblox Particle Emitter to show the Temperature (t) of our object...
We have defined 3 Particle Emitters: Cold (t=0), Normal (t=5000), Hot (t=10000).
To render the Temperature, we shall do Linear Interpolation of the 3 Particle Emitters...
COLD Particle Emitter (t=0)
Acceleration: 0, 0, 0
Color: 0 0.333333 1 1 0 1 0.333333 1 1 0
Drag: 5
EmissionDirection: Enum.NormalId.Top
Lifetime: 5 10
LightEmission: 1
LightInfluence: 1
Orientation: Enum.ParticleOrientation.FacingCamera
Rate: 20
Rotation: 0 180
RotSpeed: -170 -170
Size: 0 1 0 1 1 0
Speed: 0 0
SpreadAngle: 10, 10
Texture: rbxasset:textures/particles/sparkles_main.dds
TimeScale: 1
Transparency: 0 0 0 1 0 0
VelocityInheritance: 0
ZOffset: 0
NORMAL Particle Emitter (t=5000)
Acceleration: 0, 0, 0
Color: 0 0.333333 0.666667 0 0 1 0.333333 0.666667 0 0
Drag: 10
EmissionDirection: Enum.NormalId.Top
Lifetime: 5 10
LightEmission: 0
LightInfluence: 1
Orientation: Enum.ParticleOrientation.FacingCamera
Rate: 20
Rotation: 0 0
RotSpeed: 0 0
Size: 0 0.2 0 1 0.2 0
Speed: 5 5
SpreadAngle: 50, 50
Texture: rbxasset:textures/particles/sparkles_main.dds
TimeScale: 1
Transparency: 0 0 0 1 0 0
VelocityInheritance: 0
ZOffset: 0
HOT Particle Emitter (t=10000)
Acceleration: 0, 0, 0
Color: 0 1 0.333333 0 0 1 1 0.333333 0 0
Drag: 0
EmissionDirection: Enum.NormalId.Top
Lifetime: 5 10
LightEmission: 0
LightInfluence: 0
Orientation: Enum.ParticleOrientation.FacingCamera
Rate: 20
Rotation: 0 0
RotSpeed: 0 0
Size: 0 0.4 0 1 0.4 0
Speed: 1 1
SpreadAngle: 50, 50
Texture: rbxasset:textures/particles/sparkles_main.dds
TimeScale: 1
Transparency: 0 0 0 1 0 0
VelocityInheritance: 0
ZOffset: 0Values to be interpolated...
Color:
COLD:
0 0.333333 1 1 0
1 0.333333 1 1 0
NORMAL:
0 0.333333 0.666667 0 0
1 0.333333 0.666667 0 0
HOT:
0 1 0.333333 0 0
1 1 0.333333 0 0
Drag:
COLD: 5
NORMAL: 10
HOT: 0
LightEmission:
COLD: 1
NORMAL: 0
HOT: 0
LightInfluence:
COLD: 1
NORMAL: 1
HOT: 0
Rotation:
COLD: 0 180
NORMAL: 0 0
HOT: 0 0
RotSpeed:
COLD: -170 -170
NORMAL: 0 0
HOT: 0 0
Size:
COLD: 0 1 0 1 1 0
NORMAL: 0 0.2 0 1 0.2 0
HOT: 0 0.4 0 1 0.4 0
Speed:
COLD: 0 0
NORMAL: 5 5
HOT: 1 1
SpreadAngle:
COLD: 10, 10
NORMAL: 50, 50
HOT: 50, 50The properties of the Particle Emitters were dumped with the dumpParticleEmitter function in DigitalTwin.lua.
Note that rbxasset won't work for setting the Texture...
emitter.Texture = "rbxasset:textures/particles/sparkles_main.dds"But rbxassetid works OK...
-- Texture for the particles: "star sparkle particle" by @Vupatu
-- https://www.roblox.com/library/6490035152/star-sparkle-particle
emitter.Texture = "rbxassetid://6490035152"To create a Particle Emitter for Normal Temperature, we call createParticleEmitter in DigitalTwin.lua
-- Create a Particle Emitter for Normal Temperature
local emitter = createParticleEmitter()To interpolate the Particle Emitter for High / Mid / Low Temperatures, we call updateParticleEmitter in DigitalTwin.lua
-- Gradually update the emitter for Temperature=10,000 to 0
updateParticleEmitter(emitter, T_MAX)
wait(5)
for t = T_MAX, T_MIN, -600 do
print(string.format("t: %d", t))
updateParticleEmitter(emitter, t)
wait(4)
endHere's how the Interpolating Particle Emitter looks...