HDPM01
Serial Interface
The I
2
C interface is used for accessing calibration data as well as reading measurement result from AD
conversion.
The EEPROM and ADC is sharing the same I
2
C bus but with different chip address assigned. The
EEPROM chip address is set to 0xA1(in the case of read), write operation is not allowed. For AD part,
the chip address is set to 0xEE. So this module used two different addresses for calibration data and
AD converting data accessing. Calibration EEPROM data read operation is fully compatible to 24C02.
Bus drive timing should be referred to the specification of this part as well.
Coefficient
C1(MSB:LSB)
C2(MSB:LSB)
C3(MSB:LSB)
C4(MSB:LSB)
C5(MSB:LSB)
C6(MSB:LSB)
C7(MSB:LSB)
A
B
C
D
EEPROM ADDRESS
(16:17)
(18:19)
(20:21)
(22:23)
(24:25)
(26:27)
(28:29)
(30)
(31)
(32)
(33)
AD chip address is set to 0xEE(device write address), 0xEF(device read address). In order to get
the AD value D1 and D2, you have to follow the following timing sequence:
Pressure Measure:
1110111
1110111 1111110
1110111 1111111 1111000
1
A MSB
A
LSB
N P
1
A
S
0
A
0
A
P D S
1
A
0
A
S
Temperature Measure:
S 11101110
A
11111111
A
11101000
A
P D S 11101110
A
11111101
A
S 11101111
A MSB
A
LSB
N P
S: start condition
P: stop condition
A (
bold) : acknowledge from slave
A : acknowledge from master
N: no acknowledge from master (send out bit 1 instead)
D : delay for 40ms minimum
MSB: conversion result MSB
LSB: conversion result LSB.
Remark:
Before start an AD conversion cycle, remember to pull high for XCLR pin so that the system is no longer
in the reset state.
All data read from the module is in hex format.
After first power on, the first read data should be disregarded, and only the second value should be
used. This can assure that any unstable data after reset can be filtered out.
Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: sales@hoperf.com http://www.hoperf.com
9
HOPERF [ Hope Microelectronics co., Ltd ]
