Resistive Sensor Command
Tag 0x80-0x8f command for resistive sensor are explained in this page.
Keyword
NA: Not applicable, this command should no be sent by the sensor/application.
None: No data contained in this command, data length can be set to 0x00.
Output: Data from user application to sensor.
Input: Data from sensor to user application.
Tag 0x80
Meaning:
Set resistive sensor measurement configuration.
Data Format - Output:
Byte Length 1 1 1 1 1 1 Meaning CH0 Gain CH1 Gain CH2 Gain CH3 Gain CH4 Gain CH5 Gain CH Gain: Code given below. Set the channel is activate or not, and how many times the measured value is amplified.
Gain code OFF 0xff x1 0x00 x2 0x01 x4 0x02 x8 0x03 x16 0x04 x32 0x05 x64 0x06 x128 0x07 This configuration command have to be called every time before
0x81start command.Data Format - Input:
Same as send format. Same format will acknowledge after command is executed.
Tag 0x81
Meaning:
Start resistive sensor measurement. Measurement will continue until
0x82stop command is called. Data reply with tag0x86.Data Format - Output:
Byte Length 1 1 Meaning IDAC Current Data Rate
IDAC Current Code Data Rate Code 10uA 0x01 2.5Hz 0x00 50uA 0x02 5Hz 0x01 100uA 0x03 10Hz 0x02 250uA 0x04 16.6Hz 0x03 500uA 0x05 20Hz 0x04 750uA 0x06 50Hz 0x05 1000uA 0x07 60Hz 0x06 1500uA 0x08 100Hz 0x07 2000uA 0x09 200Hz 0x08 400Hz 0x09 800Hz 0x0a 1000Hz 0x0b 2000Hz0x0c 4000Hz0x0d IDAC Current is the current pass through the resistive sensor, the maximum supply voltage is 3.3V, all resistive sensor are in series. Since the internal reference voltage regulation, maximum voltage on each sensor should not exceed 2.5V.
Data Rate is shared between all channel, for example, if 100Hz DR is set and 4 channel is activated, DR on each channel is 25Hz.
Data Format - Input:
Same as send format. Same format will acknowledge after command is executed.
Tag 0x82
Meaning:
Stop resistive sensor measurement.
Data Format - Input:
None.
Data Format - Output:
Same as send format. Same format will acknowledge after command is executed.
Tag 0x86
Meaning:
Reply
Data Format - Input:
NA.
Data Format - Output:
Byte Length 2 - 12 Meaning ADC Value (CH0-CH5) ADC Value: Two bytes two's complement value. Returned number of values depend on how many channel is activated, smaller channel data go first.