DS-0355 Datasheet, PDF (5/16 Pages) All Sensors Corporation – DLH Series Low Voltage Digital Pressure Sensors

Operation Overview
Figure 2 - DLH Communication Model
Start-Single Command
Command
Start-Single
Internal State
Idle
Interal Operation
Idle
New Data Available
EOC
Start-Average2 / 4 / 8 / 16 Commands (Auto Averaging)
Command
Start-Average2/4/8/16
Internal State
Idle
Interal Operation
Idle
New Data Available
EOC
Active
ADC (Temp, Zero, Pressure)
DSP
Data Read
Idle
Idle
Start-Single
Active
ADC (Temp, Zero, Pressure)
Idle
DSP
Idle
Active
ADC (Temp, Zero, Pressure)1
ADC (Temp, Zero, Pressure)n DSP
Data Read
Idle
Idle
Start-Average2/4/8/16
Active
ADC (T, Z, P)…
Digital Interface Command Formats
When requesting the start of a measurement, the command format for both I2C and SPI is the same.
When requesting sensor status over I2C, the host simply performs a 1-byte read transfer.
When requesting sensor status over SPI, the host must send the Status Read command byte while reading 1 byte.
When reading sensor data over I2C, the host simply performs a 7-byte read transfer.
When reading sensor data over SPI, the host must send the 7-byte Data Read command while reading the data.
See Table 1 below for Measurement Commands, Sensor Data read and Sensor Status read details.
Table 1 - DLH Sensor Command Set
Measurement Commands (I2C or SPI)
Description
Command ( 3 bytes )
Start‐Single
0xAA 0x00 0x00
Start‐Average2
0xAC 0x00 0x00
Start‐Average4
0xAD 0x00 0x00
Start‐Average8
0xAE 0x00 0x00
Start‐Average16 0xAF 0x00 0x00
Read Sensor Data
I2C Read of 7 bytes from device
Read of 7 bytes from device
SPI Host must send [0xF0], then 6 bytes of [0x00] on MOSI
Sensor Returns 7 bytes on MISO
Read Sensor Status
I2C Read of 1 byte from device.
Read of 1 byte from device
SPI Host must send [0xF0] on MOSI
Sensor Returns 1 byte on MISO
All Sensors
DS-0355 Rev A
Page 5