library(cumulocityr)
library(knitr)
This vignette introduces the main functions with a few examples.
Credentials and base url for cumulocity are stored in a user’s private .Renviron
file.
The credentials are defined as follows:
CUMULOCITY_base_url = "[tenant url]"
CUMULOCITY_usr = "[username]"
CUMULOCITY_pwd = "[password]"
CUMULOCITY_device_id = "[an example device id]"
The tenant url should be of the form “https://tenant_name.cumulocity.com”. CUMULOCITY_device_id
is provided for convenience, but is not required by any of the main functions.
The file .Renviron
can be edited with usethis::edit_r_environ()
.
Get devices for the tenant and display a few columns. If no arguments are passed, get_devices()
returns all devices.
devices <- get_devices()
print(devices[,c("type", "name", "id")])
#> type name id
#> 1 c8y_SensorPhone Pixel 2 XL 1200
#> 2 c8y_Demo A demo device 200
#> 3 <NA> DemoDevice 51868
#> 4 c8y_MQTTDevice Temperature #1 53700
Get measurements for device “Temperature #1” and plot the result. Datetimes are returned as character strings; we first convert to POSIXct
before plotting.
meas <- get_measurements(device_id = 53700,
num_rows = 100,
date_from = "2019-09-30T19:59:00Z")
kable(head(meas[c("time", "type", "c8y_Temperature.T.value")]))
time | type | c8y_Temperature.T.value |
---|---|---|
2019-09-30T19:59:00.850Z | c8y_Temperature | 2.079117 |
2019-09-30T19:59:05.851Z | c8y_Temperature | 9.135455 |
2019-09-30T19:59:10.850Z | c8y_Temperature | 8.090170 |
2019-09-30T19:59:15.851Z | c8y_Temperature | 6.691306 |
2019-09-30T19:59:20.853Z | c8y_Temperature | 5.000000 |
2019-09-30T19:59:25.851Z | c8y_Temperature | 3.090170 |
time_parsed <- as.POSIXct(meas$time, format = "%Y-%m-%dT%H:%M:%OSZ", tz = "Z")
plot(time_parsed, meas$c8y_Temperature.T.value, type = "l",
xlab = "Time", ylab = "Temperature (deg C)")
Similarly, we can get events for the same device:
events <- get_events(device_id = 53700,
num_rows = 6,
date_from = "2019-09-30T19:59:00Z")
kable(events[c("type", "time", "c8y_Position.lng", "c8y_Position.alt")])
type | time | c8y_Position.lng | c8y_Position.alt |
---|---|---|---|
c8y_LocationUpdate | 2019-10-01T04:53:57.435Z | 77 | 88 |
c8y_LocationUpdate | 2019-10-01T04:53:52.435Z | 33 | 44 |
c8y_LocationUpdate | 2019-10-01T04:53:47.434Z | 22 | 33 |
3 | 2019-10-01T04:53:42.432Z | NA | NA |
c8y_LocationUpdate | 2019-10-01T04:51:27.419Z | 77 | 88 |
c8y_LocationUpdate | 2019-10-01T04:51:22.418Z | 33 | 44 |
By default, the content is parsed, but it is possible to return a list of JSON objects.
meas_03 <- get_measurements(device_id = 53700,
num_rows = 2,
date_from = "2019-09-30T19:59:00Z",
parse_json = FALSE)
print(meas_03)
#> [[1]]
#> [1] "{\"next\":\"https://mg.cumulocity.com/measurement/measurements?dateTo=2019-10-16T15:31:16Z&pageSize=2&source=53700&dateFrom=2019-09-30T19:59:00Z¤tPage=2\",\"self\":\"https://mg.cumulocity.com/measurement/measurements?dateTo=2019-10-16T15:31:16Z&pageSize=2&source=53700&dateFrom=2019-09-30T19:59:00Z¤tPage=1\",\"statistics\":{\"totalPages\":null,\"currentPage\":1,\"pageSize\":2},\"measurements\":[{\"self\":\"https://mg.cumulocity.com/measurement/measurements/53701\",\"time\":\"2019-09-30T19:59:00.850Z\",\"id\":\"53701\",\"source\":{\"self\":\"https://mg.cumulocity.com/inventory/managedObjects/53700\",\"id\":\"53700\"},\"type\":\"c8y_Temperature\",\"c8y_Temperature\":{\"T\":{\"unit\":\"\\u00baC\",\"value\":2.0791169082}}},{\"self\":\"https://mg.cumulocity.com/measurement/measurements/53702\",\"time\":\"2019-09-30T19:59:05.851Z\",\"id\":\"53702\",\"source\":{\"self\":\"https://mg.cumulocity.com/inventory/managedObjects/53700\",\"id\":\"53700\"},\"type\":\"c8y_Temperature\",\"c8y_Temperature\":{\"T\":{\"unit\":\"\\u00baC\",\"value\":9.1354545764}}}]}"