Modbus Registers of Bus Probes
This topic lists Modbus registers found on Tibbo Bus Probes.
Common registers
These registers are present on all Bus Probes.
Addr. |
Name |
R/W |
Type |
Description |
200 |
ID |
R/Wp |
Unsigned |
Device ID (Modbus address). This ID must be between 1 to 247. Attempts to set an ID outside of this range will be ignored. Default ID of a Probe depends on the Probe's type: 0x40 for BP#01 (ambient temperature sensor); |
201 |
TYPE |
R |
Unsigned |
Probe type: 1 — BP#01 (ambient temperature sensor); |
203 |
SIGNATURE |
R |
Unsigned 16-bit |
Always returns 0xAA55. This is a common signature for all Bus Probes. |
207 |
USER WORD 1 |
R/W |
Unsigned 16-bit |
Users are free to save any application-specific data in this register. |
208 |
USER WORD 2 |
R/W |
Unsigned 16-bit |
Users are free to save any application-specific data in this register. |
209 |
USER WORD 3 |
R/W |
Unsigned 16-bit |
Users are free to save any application-specific data in this register. |
210 |
USER WORD 4 |
R/W |
Unsigned 16-bit |
Users are free to save any application-specific data in this register. |
211 |
MONITOR VERSION |
R |
Unsigned 16-bit |
Firmware version of the Monitor/Loader. |
212 |
FIRMWARE VERSION |
R |
Unsigned 16-bit |
Firmware version of the application firmware. |
R = read, W = write, W p= protected write (possible only while the MD button* is being pressed).
* Each Bus Probe comes with a metal pin that makes pushing and holding down the MD button easier.
Additional registers of BP#01 (ambient temperature sensor)
Addr. |
Name |
R/W |
Type |
Description |
300 |
TEMP_PROC |
R |
Signed |
Processed fixed-point temperature data expressed in steps of 0.01 degrees C. |
301 |
TEMP_RAW |
R |
Unsigned 16-bit |
Raw temperature data from the measurement IC (MCP9808). |
R = read (only)
Additional registers of BP#02 (ambient temperature and relative humidity sensor)
Addr. |
Name |
R/W |
Type |
Description |
400 |
TEMP_PROC |
R |
Signed |
Processed fixed-point temperature data expressed in steps of 0.1 degrees C. |
401 |
TEMP_RAW |
R |
Unsigned 16-bit |
Raw temperature data from the measurement IC (HIH6130). |
404 |
HUM_PROC |
R |
Unsigned |
Processed fixed-point relative humidity data expressed in steps of 0.1%. |
405 |
HUM_RAW |
R |
Unsigned 16-bit |
Raw humidity data from the measurement IC (HIH6130). |
R = read (only)
Additional registers of BP#03 (ambient light sensor)
Addr. |
Name |
R/W |
Type |
Description |
500 |
LUM_PROC |
R |
Unsigned |
Processed fixed-point luminance data expressed in steps of 1 Lux. |
501 |
LUM_RAW |
R |
Unsigned 16-bit |
Raw luminance data from the measurement IC (BH1721FVC). |
R = read (only)
Additional registers of BP#04 (3-axis accelerometer)

Addr. |
Name |
R/W |
Type |
Description |
600 |
AXIS_X_PROC |
R |
Signed 16-bit |
Processed fixed-point X-axis acceleration data expressed in steps of ~0.003G. |
601 |
AXIS_X_RAW |
R |
Signed 16-bit |
Raw X-axis acceleration data from the measurement IC (ADXL312). |
602 |
AXIS_Y_PROC |
R |
Signed 16-bit |
Processed fixed-point Y-axis acceleration data expressed in steps of ~0.003G. |
603 |
AXIS_Y_RAW |
R |
Signed 16-bit |
Raw Y-axis acceleration data from the measurement IC (ADXL312). |
604 |
AXIS_Z_PROC |
R |
Signed 16-bit |
Processed fixed-point Z-axis acceleration data expressed in steps of ~0.003G. |
605 |
AXIS_Z_RAW |
R |
Signed 16-bit |
Raw Z-axis acceleration data from the measurement IC (ADXL312). |
R = read (only)