SBOA631 August 2025 HDC1010 , HDC1080 , HDC2010 , HDC2021 , HDC2022 , HDC2080 , HDC3020 , HDC3020-Q1 , HDC3021 , HDC3021-Q1 , HDC3022 , HDC3022-Q1 , HDC3120 , HDC3120-Q1
The HDC302x family introduces a command-based interface, marking a departure from the register map-based scheme used in prior generations. Instead of writing to specific registers, HDC302x devices respond to well-defined command codes to initiate measurements, configure settings, or retrieve data. Table 2-6 shows an example of supported commands by the HDC302x devices.
This approach simplifies the interface and reduces the number of required I2C transactions, particularly in applications where only basic measurements are needed.
The forthcoming sections demonstrate how to interface with the HDC302x in both Trigger-On Demand and Auto Measurement modes, providing examples of how command-based communication is implemented in each case.
| HEX CODE (MSB) |
HEX CODE (LSB) |
COMMAND | COMMAND DETAIL |
|---|---|---|---|
| 24 | 00 | Trigger-On
Demand Mode Single Temperature (T) Measurement and Relative Humidity (RH) Measurement |
Low Power Mode 0 (lowest noise) |
| 24 | 0B | Low Power Mode 1 | |
| 24 | 16 | Low Power Mode 2 | |
| 24 | FF | Low Power Mode 3 (lowest power) | |
| 20 | 32 | Auto
Measurement Mode 1 measurement per 2 seconds. |
Low Power Mode 0 (lowest noise) |
| 20 | 24 | Low Power Mode 1 | |
| 20 | 2F | Low Power Mode 2 | |
| 20 | FF | Low Power Mode 3 (lowest power) | |
| 21 | 30 | Auto
Measurement Mode 1 measurement per second. |
Low Power Mode 0 (lowest noise) |
| 21 | 26 | Low Power Mode 1 | |
| 21 | 2D | Low Power Mode 2 | |
| 21 | FF | Low Power Mode 3 (lowest power) | |
| 22 | 36 | Auto
Measurement Mode 2 measurements per second. |
Low Power Mode 0 (lowest noise) |
| 22 | 20 | Low Power Mode 1 | |
| 22 | 2B | Low Power Mode 2 | |
| 22 | FF | Low Power Mode 3 (lowest power) | |
| 23 | 34 | Auto
Measurement Mode 4 measurements per second. |
Low Power Mode 0 (lowest noise) |
| 23 | 22 | Low Power Mode 1 | |
| 23 | 29 | Low Power Mode 2 | |
| 23 | FF | Low Power Mode 3 (lowest power) | |
| 27 | 37 | Auto
Measurement Mode 10 measurements per second. |
Low Power Mode 0 (lowest noise) |
| 27 | 21 | Low Power Mode 1 | |
| 27 | 2A | Low Power Mode 2 | |
| 27 | FF | Low Power Mode 3 (lowest power) | |
| 2C | 06 | Trigger-On
Demand Mode Single Temperature (T) Measurement and Relative Humidity (RH) Measurement |
Low Power Mode 0 (lowest noise) |
| 2C | 0D | Low Power Mode 1 | |
| 2C | 10 | Low Power Mode 2 | |
| 30 | 93 | Auto Measurement Mode | Exit, then return to Trigger-on Demand Mode. |
| E0 | 00 | Measurement Readout of
T and RH (Note: if RH and T are not updated, data read outs all FFs) |
|
|
E0 |
01 |
Measurement Readout of RH only |
|
| E0 | 02 | Measurement History Readout of Minimum T. | |
| E0 | 03 | Measurement History Readout of Maximum T. | |
| E0 | 04 | Measurement History Readout of Minimum RH. | |
| E0 | 05 | Measurement History Readout of Maximum RH. |