EMG Command

Tag 0x70-0x7f command for Electromyography (EMG) function 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.

Tag 0x70

Meaning:
Start EMG streaming with specific configuration. Recording continue until user call the stop recording command tag 0x71. Data replay from EMG sensor will use tag 0x76-0x77.

Data format - app send:

Byte Length 1 1
Meaning ODR Reply Format

Output Data Rate (ODR): Output Data Rate of the EMG value while streaming, listed on the table below.

Reply Format: There are 2 different format, each of them can output with time stamp or not.

  • Standard Mode: 12-bits accuracy, 16 data are output each notification, FIFO order

  • Accumulate Mode: 16-bits accuracy, one data is output each notification. Note that the output data rate is divided 16 under this mode, because of 16 12-bits data is accumulated into one 16-bits data.

ODR (Hz) Code
50 0xd2
100 0x69
200 0x35
400 0x1a
600 0x12
Reply Format Code Tag Details
Standard 0x01 here
Standard with Time Stamp 0x02 here
Accumulate 0x03 here
Accumulate with Time Stamp 0x04 here

Data format - app receive:
Same as send format.

Same format will acknowledge after command is executed.

Tag 0x71

Meaning: Stop EMG data streaming.

Data format - app send:
None

Data format - app receive:
Same as send format.

Same format will acknowledge to the user after command is executed.

Tag 0x72

Meaning: Return the EMG value in integer.

Data format - app send:
NA

Data format - app receive:

Byte Length 4
Meaning EMG value

EMG value: Integer. Value from 0 to 10000, higher value mean stronger EMG signal is measured.

Tag 0x76

Meaning: Return 16 EMG value in a single read.

Data format - app send:
NA

Data format - app receive:

Byte Length 32 8 (optional)
Meaning EMG Value Time Stamp

EMG value: 16 EMG value in unsigned integer, 2 bytes each, little endian. Use the following equation to convert it to mV measured:

EMG(mV) = ((EMG Value / 4095 * 3.3) - 1.65) / Gain

Time Stamp: Unsigned Long, unit is 2.4414us. Represent the data record time. Only appear when the "with time stamp" format is chosen. Pay attention that this value might not start from zero. Usually it is used to help synchronize data from multiple sensors or calculate the accurate data rate.

Tag 0x77

Meaning: Return EMG value in mV.

Data format - app send:
NA

Data format - app receive:

Byte Length 2 8 (optional)
Meaning EMG value Time Stamp

EMG value: EMG value in unsigned integer, little endian. Use the following equation to convert it to mV measured:

EMG(mV) = ((EMG Value / 65535 * 3.3) - 1.65) / Gain

Time Stamp: Unsigned Long, unit is 2.4414us. Represent the data record time. Only appear when the "with time stamp" format is chosen. Pay attention that this value might not start from zero. Usually it is used to help synchronize data from multiple sensors or calculate the accurate data rate.