Data Sheet
Page 18 ams Datasheet
Document Feedback [v1-00] 2016-Dec-23
CCS 811 − Application Register Overview
ALG_RESULT_DATA (Algorithm Results Data)
Register (0x02)
This multi-byte read only register contains the calculated eCO
2
(ppm) and TVOC (ppb) values followed by the STATUS register,
ERROR_ID register and the RAW_DATA register.
• If only eCO
2
is required, only the first 2 bytes need to be
read.
• If TVOC is required, 4 bytes need to be read.
• In a system where interrupts are not implemented and the
host needs to poll the STATUS register to determine
whether there is new data, an efficient alternative is to
read 5 bytes in a single transaction since that returns eCO
2
,
TVOC and the status register.
• Optionally, all 8 bytes could be read in a single transaction,
so that even the error status and the raw data is available.
Figure 14:
Algorithm Results Register Byte Order
RAW_DATA Register (0x03)
Two byte read only register which contains the latest readings
from the sense resistor.
The most significant 6 bits of the Byte 0 contain the value of the
current through the sensor (0µA to 63A).
The lower 10 bits contain (as computed from the ADC) the
readings of the voltage across the sensor with the selected
current (1023 = 1.65V)
Figure 15:
RAW_DATA Register Byte Order
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 & 7
eCO
2
High Byte eCO
2
Low Byte
TVOC High Byte TVOC Low Byte STATUS ERROR_ID See RAW_DATA
Byte 0 Byte 1
7654321076543210
Current Selected 5:0 Raw ADC reading 9:0