Recording readings with datalogger.log()
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Which line saves a temperature reading as a row in the micro:bit data log?
2. What does each call to datalogger.log() do?
3. In datalogger.createCV("temperature", input.temperature()), what is "temperature"?
4. You want a reading saved every second for a minute. Where should datalogger.log() go?
5. Do you need to write code to record the time of each row?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1datalogger.log(datalogger.createCV("temperature", input.temperature())) | ASaves one new row in the data log with a column called temperature holding the current temperature reading | |
| 2datalogger.log(datalogger.createCV("temp", input.temperature()), datalogger.createCV("light", input.lightLevel())) | Bbasic.forever(function () { datalogger.log(datalogger.createCV("temperature", input.temperature())) basic.pause(5000) }) | |
| 3To record readings over time, put datalogger.log() inside a loop so each pass adds a new row to the log | Cbasic.forever(function () { datalogger.log(datalogger.createCV("temperature", input.temperature())) }) | |
| 4Pausing between logs spaces the readings out, for example one row every 5 seconds | DSaves one row with two columns, temp and light, so two readings are recorded together at the same moment | |
| 5datalogger.log("temperature", input.temperature()) | EThe reading is not wrapped in datalogger.createCV(), so the column name and value are not paired properly for the log. | |
| 6datalogger.log(datalogger.createCV("temperature", input.temperature)) | Finput.temperature is missing its brackets (), so the function is never called and no reading is taken. |
C
Definitions
datalogger.log()
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
datalogger.___(
datalogger.createCV("temperature",
input.temperature()))
2.
datalogger.log(
datalogger.________("temperature",
input.temperature()))
3.
basic._______(() => datalogger.log(
datalogger.createCV("temperature",
input.temperature())))
4.
datalogger.log(
datalogger.createCV("l", input.__________()),
datalogger.createCV("s", input.soundLevel()))
5.
datalogger.log(
datalogger.createCV("temperature",
input.___________()))
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
datalog.log(
B
datalogger.createCV("temp",
C
input.temperature()))
Question 2
A
basic.forever(function () {
B
datalogger.log(
C
datalogger.createCV(tmp,
D
input.temperature()))
E
basic.pause(5000)
F
})
Question 3
A
for (let i = 0; i < 10; i--) {
B
datalogger.log(
C
datalogger.createCV("tmp",
D
input.temperature()))
E
basic.pause(1000)
F
}
Question 4
A
datalogger.log(
B
datalogger.createCv("temp",
C
input.temperature()),
D
datalogger.createCV("light",
E
input.lightLevel()))
Question 5
A
basic.forever(function () {
B
datalogger.save(
C
datalogger.createCV("tmp",
D
input.temperature()))
E
basic.pause(1000)
F
})
Answer Key
Recording readings with datalogger.log()
Section A: Quick Questions
Q1
B — datalogger.log(datalogger.createCV("temperature", input.temperature()))
Q2
B — Adds a new row to the data log
Q3
A — The column name for the reading
Q4
A — Inside a loop, such as basic.forever()
Q5
A — No, the micro:bit adds a timestamp to each row
Section B: Match the Pairs
Q1
datalogger.log(datalogger.createCV("temperature", input.temperature())) → Saves one new row in the data log with a column called temperature holding the current temperature reading
Q2
datalogger.log(datalogger.createCV("temp", input.temperature()), datalogger.createCV("light", input.lightLevel())) → Saves one row with two columns, temp and light, so two readings are recorded together at the same moment
Q3
To record readings over time, put datalogger.log() inside a loop so each pass adds a new row to the log → basic.forever(function () {
datalogger.log(datalogger.createCV("temperature", input.temperature()))
})
Q4
Pausing between logs spaces the readings out, for example one row every 5 seconds → basic.forever(function () {
datalogger.log(datalogger.createCV("temperature", input.temperature()))
basic.pause(5000)
})
Q5
datalogger.log("temperature", input.temperature()) → The reading is not wrapped in datalogger.createCV(), so the column name and value are not paired properly for the log.
Q6
datalogger.log(datalogger.createCV("temperature", input.temperature)) → input.temperature is missing its brackets (), so the function is never called and no reading is taken.
Section C: Definitions
Q1
datalogger.log() — Saves one row of named sensor readings, with a timestamp, in the micro:bit data log. Each call adds a new row, so use it in a loop to record readings over time.Section D: Fill in the Blanks
Q1
datalogger.log(
datalogger.createCV("temperature",
input.temperature()))Q2
datalogger.log(
datalogger.createCV("temperature",
input.temperature()))Q3
basic.forever(() => datalogger.log(
datalogger.createCV("temperature",
input.temperature())))Q4
datalogger.log(
datalogger.createCV("l", input.lightLevel()),
datalogger.createCV("s", input.soundLevel()))Q5
datalogger.log(
datalogger.createCV("temperature",
input.temperature()))Section E: Spot the Error
Q1
A — The object is called datalogger, not datalog. The line should start datalogger.log( so the row is saved in the micro:bit data log.
Q2
C — The column name must be a string in quotes. It should be datalogger.createCV("tmp", so the log has a named column.
Q3
A — i-- makes i count down, so i < 10 is always true and the loop never stops. It should be i++ so the loop logs exactly 10 rows.
Q4
B — Function names are case sensitive. It must be createCV with a capital V, not createCv.
Q5
B — There is no datalogger.save(). The command that adds a row to the data log is datalogger.log(.