BSL 00000200

MP Type	I2C
OS Type	Multi-Thread Mbed , etc
Calculation accuracy	floating-point calculation
Characteristic Conversion	linear conversion
Filter	Non
Diagnostics	SP Max/Min , CP write error , MP ACK

Software Specifications

In this section, we will use the OSS-EC I2C component ( TI HDC1080 ) as an example.

Intended use scenarios

After “Power ON Reset”, the program moves to “measurement” and acquires temperature and humidity from the temperature and humidity sensor via I2C communication.
When “measurement” is selected, the heater is turned on by “Mode change” when the temperature is low. However, when the voltage is low, “Mode change” turns the heater OFF.
If the temperature and humidity are outside the upper and lower limits of the “measurement”, it is judged as NG.If nonzero on failure (nack) in I2C communication is repeated iCom_retry_num times of consecutive retries, it is judged NG.
If NG is determined, “Software Reset” is performed.

summary

The software architecture of the OSS-EC is configured to pair with the hardware architecture of HDC1080, as shown in ( Fig. 1).
The state of an HDC1080 is changed by a command from the application as shown in (Fig.2).
The interface between the application and PCMP is the argument structure cmd and the return value structure res, as shown in (Fig.3).
Command sequence ( fig.4 )
Data table
File

Blue label characters are data related to application.

Data table

#define Label	Value	Data contents
iPCMP_cyc	1000U	PCMP Function call cycle 1000[ms]
iError_times	3U	PCMP Error times 3times
iCom_retry_num	3U	I2C communication retry 3times
iTemp_low	5.0F	Judgment temperature value 5.0℃for turning on the heater
iHDC1080_dat_cnf_pwrst	(iMODE+iTRES+iHRES)	HDC1080 configuration register setting value( state : Power ON Reset )
iHDC1080_dat_cnf_nonheat	(iMODE+iTRES+iHRES)	HDC1080 configuration register setting value( state : Measurement non-heat )
HDC1080_dat_cnf_heat	(iHEAT+iMODE+iTRES+iHRES)	HDC1080 configuration register setting value( state : Measurement heat )
iHDC1080_dat_cnf_swrst	(iRST+iMODE+iTRES+iHRES)	HDC1080 configuration register setting value( state : Software Reset )
iRST	(iBit15*1)	0:Normal 1:software reset
iHEAT	(iBit13*1)	0:Heater disable 1:Heater enable
iMODE	(iBit12*1)	0:Temperature or Humidity is acquired 1:Temperature and Humidity are acquired in sequence, Temperature first
iTRES	(iBit10*0)	Temperature 0:14bit 1:11bit
iHRES	(iBit09*0)+(iBit08*0)	Humidity 00:14bit 01:11bit 10:8bit
iEndian	iBig	Endian select
iI2C_SDA	D14	SDA Pin
iI2C_SCL	D15	SCL Pin
iI2C_frequency	400000	Frequency 400kHz