A customer may use these MAX30003 register settings to measure ECG, but the settings should be modified according to the custom application. Note: When working with the MAXREFDES100# Health Sensor Platform (HSP) and using the HSP tethered (USB cable connected), the third VCM lead for body bias must be used.
Here are the settings:
CNFG_GEN: 0x080000 This is for lead-off detection disabled. If you want lead-off detection enabled, see datasheet Table 21 for details.
CNFG_CAL: 0x000000 The calibration voltage should be disabled while measuring ECG.
CNFG_EMUX: 0x000000 Connect ECG leads, disconnect calibration voltages.
CNFG_ECG: 0x805000 128sps, DLPF and DHPF enabled.
CNFG_RTOR1: 0x3F6300 R-R enabled with default settings.
CNFG_RTOR2: 0x202400 default R-R settings.
SYNCH and FIFO_RST: set to 0x000000 to begin new ECG recording.
A similar post on mbed.org can be found here: https://os.mbed.com/questions/79566/The-best-configuration/
