Adding Custom Device Firmware¶
The Data Capture Lab supports data collection from any third-party hardware. Follow the steps below to use your device in the Data Capture Lab:
Implement one of the SensiML Interface Specifications and update your device firmware. We provide two firmware protocols for interfacing with your device. The Simple Streaming Interface or the MQTT-SN Interface.
We suggest starting with the Simple Streaming Interface. The Simple Streaming Interface allows you to quickly prototype a project, but does not offer run-time configuration options.
The MQTT-SN Interface grants full command and control capabilities within the Data Capture Lab, but requires integrating MQTT and it’s topics.
Create a Device Plugin. A Device Plugin is created by implementing an .SSF (SensiML Sensor Format) file. We will go over how to define the .SSF file below.
Device Plugins¶
Device Plugins are a list of properties that describe how the DCL will collect data from your device. For example, the device plugin may contain a list of sample rates that your device supports. This allows the DCL to collect data from any device that has been built to accept the supported parameters below.
How to Import a Device Plugin¶
The Data Capture Lab allows you to import Device Plugins via .SSF files. We will define the SSF file format in the next section below. For now, just note that you can import your SSF file through the menu item Edit → Import Device Plugin…
Next, you will be able to select your plugin protocol
SSF Files are used for both Simple Streaming and MQTT-SN. The only difference in the files are the device connection types used in the file.
Example SSF Files¶
You can download example SSF files for both the MQTT-SN and Simple Streaming protocols below. These files were built using the QuickFeather Development Kit.
SSF File Format¶
The Data Capture Lab allows you to import Device Plugins via .SSF files. Let’s go over the SSF file format and how this file will be used in the DCL. The SSF file format is a JSON based format with JSON properties that the DCL will use when configuring your Device Plugin.
When you import your Device Plugin the DCL will use the plugin to dynamically build out a screen for a user to configure sensor properties during data collection. See a screenshot below for a better understanding of how these parameters will be displayed in the DCL:
Notice that there are options for selecting your Device Plugin sample rate and sensors in the screenshot.
Now, let’s look at how this screen will map to the SSF file format. See below for a code snippet for the SensorTile.box device. We will give more detailed definitions about the JSON properties within this snippet in the next section.
{
"uuid": "579e81fb-8347-48e9-8939-fcf50bcc0718",
"device_name": "SensorTile.box",
"device_manufacturer": "ST Microelectronics",
"plugin_developer": "SensiML",
"firmware_download_links": [
{
"title": "Data Collection Firmware",
"description": "",
"link": "https://sensiml.com/documentation/firmware/"
},
],
"documentation_links": [
{
"title": "Getting Started Guide",
"description": "",
"link": "https://sensiml.com/documentation/guides/getting-started/overview.html"
},
],
"collection_methods": [
{
"name": "live",
"display_name": "Live Stream Capture",
"storage_path": null,
"is_default": true
},
{
"name": "sd_card",
"display_name": "SD Card",
"storage_path": null,
"is_default": false
}
],
"device_connections": [
{
"display_name": "Serial Port",
"value": 1,
"is_default": true,
"serial_port_configuration": {
"com_port": null,
"baud": 921600,
"stop_bits": 1,
"parity": 0,
"handshake": 0,
"max_live_sample_rate": 209
}
}
],
"capture_sources": [
{
"max_throughput": 0,
"name": "Motion",
"part": "Default",
"sample_rates": [
6667,
3333,
1666,
833,
416,
208,
104,
52,
26
],
"is_default": true,
"sensors": [
{
"column_count": 3,
"is_default": true,
"column_suffixes": [
"X",
"Y",
"Z"
],
"type": "Accelerometer",
"parameters": [
{
"name": "Sensor Range",
"values": [
{
"actual_value": 20,
"num_bytes": 1,
"display_value": "+/- 2G"
},
{
"actual_value": 40,
"num_bytes": 1,
"display_value": "+/- 4G"
},
{
"actual_value": 80,
"num_bytes": 1,
"display_value": "+/- 8G"
},
{
"actual_value": 160,
"num_bytes": 1,
"display_value": "+/- 16G"
}
],
"units": null
}
],
"sensor_id": 1229804865,
"can_live_stream": true
},
{
"column_count": 3,
"is_default": true,
"column_suffixes": [
"X",
"Y",
"Z"
],
"type": "Gyroscope",
"parameters": [
{
"name": "Sensor Range",
"values": [
{
"actual_value": 0,
"num_bytes": 1,
"display_value": "+/- 2000 DPS"
},
{
"actual_value": 1,
"num_bytes": 1,
"display_value": "+/- 1000 DPS"
},
{
"actual_value": 2,
"num_bytes": 1,
"display_value": "+/- 500 DPS"
},
{
"actual_value": 3,
"num_bytes": 1,
"display_value": "+/- 250 DPS"
},
{
"actual_value": 4,
"num_bytes": 1,
"display_value": "+/- 125 DPS"
}
],
"units": null
}
],
"sensor_id": 1229804871,
"can_live_stream": true
}
],
"sensor_combinations": [
{
"combined_id": 1229804803,
"sensors_in_combo": [
1229804865,
1229804871
]
}
]
},
{
"max_throughput": 0,
"name": "Audio",
"part": "Default",
"sample_rates": [
16000
],
"is_default": false,
"sensors": [
{
"column_count": 1,
"column_suffixes": [
""
],
"type": "Microphone",
"is_default": true,
"parameters": [
{
"name": "Bits/sample",
"values": [
{
"actual_value": 16,
"num_bytes": 1,
"display_value": "16"
}
],
"units": null
},
{
"name": "Channels",
"values": [
{
"actual_value": 1,
"num_bytes": 8,
"display_value": "One"
}
],
"units": null
}
],
"sensor_id": 1096107087,
"can_live_stream": false
}
],
"sensor_combinations": null
}
],
"is_little_endian": true
}
JSON Object Definitions¶
Device Plugin
uuid |
(GUID) A unique ID to identify a plugin |
device_name |
(String) Name of your device |
device_manufacturer |
(String) Name of the developer or company that manufacturers the device |
plugin_developer |
(String) Name of the developer or company that developed the Device Plugin |
firmware_download_links |
(List<Object>) A list of links that a user can use to find information on updating the device firmware for data collection. See how to define a firmware_download_link in the Plugin Link section |
documentation_links |
(List<Object>) A list of links that a user can use to find information on general tutorials or useful documentation about the device. See how to define a documentation_link in the Plugin Link section |
capture_sources |
(List<Object>) Defines each of the sensors in your device. See how to define the capture_source JSON property in the Capture Source section |
collection_methods |
(List<Object>) Defines the collection methods your board supports. See how to define the collection_method JSON property in the Collection Method section |
device_connections |
(List<Object>) Defines the connection protocols your board supports. See how to how to define the device_connection JSON property in the Device Connection section |
is_little_endian |
(Boolean) Defines if the data is big endian (false) or little endian (true). Sensor data is transmitted in the byte order of the system. You will see incorrect data being captured if this is specified incorrectly |
Plugin Link
title |
(String) A user-friendly title for the link. Example: Data Collection Tutorial |
description |
(String) An optional field used to describe the contents of the link |
link |
(String) Hyperlink URL location. Example: https://sensiml.com/documentation/firmware/ |
Capture Source
name |
(String) Display name for your source. In the example above, |
part |
(String) Name of the device hardware part. Set to “Default” if |
sample_rates |
(List<Integer>) A list of all available sample rates your |
is_default |
(Boolean) Defines if this capture source is the default option |
sensors |
(List<Object>) Defines the sensors your board supports. See |
sensor_combinations |
(List<Object>) Defines a list of definitions for making a |
Sensor
sensor_id |
(Integer) Identification number of the sensor. This will be |
type |
(String) Class of the sensor. Example: Accelerometer, |
is_default |
(Boolean) Defines if this sensor is selected as a default |
column_count |
(Integer) Defines how many columns of data this sensor sends |
column_suffixes |
(List<String>) A list of strings used to describe sensors Axes |
parameters |
(List<Object>) Defines a list of sensor specific parameters, |
can_live_stream |
(Boolean) Defines if this sensor can also be live-streamed |
Sensor Parameter
name |
(String) Name of the parameter sent as an unsigned integer |
values |
(List<Object>) Defines a list of available parameter values |
units |
(String) Defines the unit of the parameter. This property |
Sensor Parameter Value
display_value |
(String) Value to be displayed to the user |
actual_value |
(Integer) Value to be used when configuring the device (saved |
num_bytes |
(Integer) The number of bytes that the actual_value property |
Sensor Combination
Sensor combinations are used to create a virtual/combined sensor to be treated as a single sample. When all sensors in a defined combination are selected in the Data Capture Lab configuration UI, the Data Capture Lab will automatically use the combined_id of a given combination when configuring the device.
combined_id |
(Integer) ID for the combination |
sensors_in_combo |
(List<Integer>) Defines a list of unsigned integers that match |
Collection Method
name |
(String) Internal name for the collection method. There are
|
display_name |
(String) Name to be displayed to the user |
is_default |
(Boolean) Defines if this collection method is the default |
storage_path |
(String) Location where files being saved to the device should |
Device Connection
Device connections define the protocol for how you will connect to your device (Bluetooth-Low Energy UART, Serial/Wired UART Port, or Wi-Fi). Note: Bluetooth-Low Energy UART is not supported through imported Device Plugins
display_name |
(String) Name to be displayed to the user |
value |
(Integer) Value to define the connection type. There are
|
is_default |
(Boolean) Defines if this connection is the default option |
bluetooth_le_configuration |
(Object) Defines Bluetooth-Low Energy UART specific |
serial_port_configuration |
(Object) Defines Serial/Wired UART Port specific configuration |
wifi_configuration |
(Object) Defines Wi-Fi specific configuration options. |
Bluetooth UART Configuration
For Bluetooth-Low Energy UART connections, the service and characteristic UUIDs are needed. It is assumed that the BLE UART will be following similar protocol to the Nordic UART Service. This allows the device to act as a virtual COM port, enabling serial communication much the same as a wired connection.
service_uuid |
(GUID) UART Service ID |
char_tx_uuid |
(GUID) UART Transmit Characteristic ID |
char_rx_uuid |
(GUID) UART Receive Characteristic ID |
max_live_sample_rate |
(Integer) The maximum frequency (in Hertz) your device is able |
Serial Port Configuration
com_port |
(String) COM port should be left as null. This will be set |
baud_rate |
(Integer) Speed at which you communicate. Default: 115200 Refer to Microsoft BaudRate Documentation for more details |
stop_bits |
(Integer) Number of stop bits. Default: 1 Refer to Microsoft StopBits Documentation for more details |
parity |
(Integer) Parity scheme. Default: 0 Refer to Microsoft Parity Documentation for more details |
handshake |
(Integer) Handshake scheme. Default: 0 Refer to Microsoft Handshake Documentation for more details |
max_live_sample_rate |
(Integer) The maximum frequency (in Hertz) your device is able |
Device Connection Types¶
MQTT-SN Device Connections
Currently, MQTT-SN is done only on a serial port. Below is an example of that configuration.
{
"display_name": "Serial Port",
"value": 1,
"is_default": true,
"serial_port_configuration": {
"com_port": null,
"baud": 921600,
"stop_bits": 1,
"parity": 0,
"handshake": 0,
"max_live_sample_rate": 209
}
}
Simple Streaming Device Connections
Simple streaming interface currently supports serial ports and a simplified Wi-Fi interface.
For the serial port
{
"display_name": "Serial Port",
"value": 1,
"is_default": true,
"serial_port_configuration": {
"com_port": null,
"baud": 460800,
"stop_bits": 1,
"parity": 0,
"handshake": 0,
"max_live_sample_rate": 3301
}
}
And for Wi-Fi
{
"display_name": "Wi-Fi",
"value": 2,
"is_default": true,
"wifi_configuration": {
"use_external_broker": false,
"external_broker_address":"",
"broker_port":1885,
"device_ip_address": null,
"device_port": 0,
"max_live_sample_rate": 1000000
}
}