In the next three days the posts will be about the components of provided and additional equipments. The today's players:
1. AD8232-EVALZ
This is a single-lead, heart rate monitor front end is based on AD8232 chip. The functional block diagram is seen below. The measured bioelectric signals are sensed via attached electrodes on the human body. This device can operate with 2 (left, right) or 3 (left, right and driven) electrodes. The two (L and R) electrodes connect to the instrumental amplifier (IA), which is consists of the listened parts:
- RFI filter,
- Well-matched transconductance amplifiers,
- DC blocking amplifier,
- Integrator.
The operational amplifier (A1) is a general-purpose, rail-to-rail device for additional gain and low-pass filtering.
The right leg drive amplifier (A2) inverts the presented common-mode signal of input of IA. The injected current by the RLD output counteracts the common-mode voltage and improving the common-mode rejection of measuring system.
The midsupply reference buffer (A3) generates the virtual ground.
The leads of detection can be work in two modes:
DC: only works with three electrodes configuration. This indicates that which electrode has fallen off.
AC: can be used for two electrodes configuration. This marks only the fact of falling.
The fast restore function (FR) reduces the duration of otherwise long settling tails of the high-pass filters.
The AD8232 can be used for several applications, like heart rate measurement or cardiac monitor.
2. ADuCM350EBZ Evaluation Board Development Kit
This is an ARM Cortex-M3 based microprocessor with 16 MHz clock speed. It has got 32 KB of SRAM, 16 KB of flash and 384 KB of embedded flash memory. It has 12-bit DAC and 16-bit ADC with 160 kSPS. It is designed for capabilities of amperometric, voltametric and impedometric measurement. There are three ways to supply the board: via USB port, CR2032 battery or external supply (2,5-3,6V).
The Development Kit contains the following items:
- main (mother) board
- J-Link emulator (USB-SWD/UART)
- AFE board
- Break out board
- GPIO test header board
The detailed information about the process unit of ECG measuring system is expected in the 7th blog post (Smart Clothes - 7 - ECG measurement system) on Friday or on Saturday.
3. ADT7320FBZ Flexi Board Evaluation Kit
This is a high accuracy (± 0,25 °C) digital temperature sensor. It has 16-bit sigma-delta ADC, the available temperature resolution is 0,0078 °C. The default resolution is set to 13-bit (0,0625 °C). The communication is done via SPI with low power consumption (700 μW typically).
The further discussion about the temperature measurement is expected in the 8th blog post (Smart Clothes - 8 - Intelligent lighting system) on Sunday.
Best regards,
Norbert Kovács