Low power consumption with MAXQ2010 medical data recorder (1)

Many medical applications requires no external power and data cable of the portable self-powered device, the most obvious example is the patients carry used to measure heart rate, body temperature and other health indicators of portable data recorder.

Of course, there are many complex applications even through external power supply, would need a small battery equipment secure redundant and equipment monitoring, such as hospitals, patient rooms, the environment controlled laboratory or storage device environment parameters (including temperature and humidity) continuous monitoring is required; the other portable device installation you will need an external power supply and network cable to the device easier and more flexible.

In some cases, such as the need for patients to carry medical equipment, freezer temperature detection equipment, no external power and network cables.

Portable medical equipment requirements which features? first, must be on-board power supply.

Usually available through rechargeable or non-rechargeable battery, although there are other ways (such as solar power), but this depends on the voltage and current requirements. No matter what kind of power supply, power supply efficiency must be high enough, and battery-powered portable device does not require a full load of work should be able to get to the "sleep" mode to minimize power consumption, dormant devices can be an external trigger signal or regular is "wake up", and then raise the operation rate (of course, power consumption will increase) in normal operating mode. The device should have between full-load work and "hibernate" modes of operation to perform some simple task (such as access memory or refresh LCD and LED display data), because devices typically only under certain conditions would need full-load operation capability (e.g. for sensor data filtering and decode), so that you can power and speed between a degree of balance.

Portable device even though support for wireless communication, but is not always guaranteed to be able to access the wireless network.

Depends on network conditions, a time machine in a wireless network environment, the next time it may be moved to does not have a wireless network environment, or may be caused by power outage temporarily turn off the wireless network. In these cases, if the device itself does not support wireless communication devices will need to keep collecting data stored for later upload to top level systems for data processing. There are a number of key data (such as environmental security failure data, configuration data, or device drivers) must ensure that the storage security, even if the battery fails or is removed or is missing.

Other characteristics of the portable device depends on the specific application requirements, the data can be directly through the analog sensor acquisition or through local network access to a subsystem read, portable device can only passively collecting data under certain conditions the voice alarm proactively through or to signal the alarm.

Some simple data acquisition equipment before the upload data without user intervention at all, while other devices (such as hand-held blood glucose meter or wristband-heart monitor) may require additional input and output device instead of the host system to change configurations or browse data.

Use MAXQ2010 design portable data logger

Although the industry has many options for microcontrollers, but Maxim company MAXQ series low-power microcontrollers, mixed-signal RISC MAXQ2010 characteristics that is ideal for battery-powered data acquisition devices.

MAXQ2010 have extremely low power consumption, high MIPS/mA ratio, only need a small battery current support portable applications, integrated 8 channel 12-bit ADC can collect many types of sensor data, and also supports many types of local serial interface (I2C, SPI, UART synchronous/asynchronous), can be used to access the host system and serial non-volatile storage devices, or relating to this device in the other subsystem communication.

MAXQ2010 according to the current task on computing capacity requirements by dynamically adjusting the clock frequency to change the power consumption, and when it has finished processing all of the data and events, a portable device to go to the lowest power consumption of Hibernate (stop) mode until you wake up again by application.

MAXQ2010 nuclear voltage only 1.8V, can greatly reduce power, 3V independent power supply of I/O can communicate with the external high-voltage logic. If you want to use as the lithium battery 3V button this single supply and do not want to use the dual power supply, you can use built-in integrated voltage regulator to nuclear power. In stop mode, the voltage regulator can be turned off to reduce power consumption.

MAXQ2010 to a variety of ways to read data from the sensor, if acquisition of analog sensor data, and can use built-in 12-bit ADC, multi channel support, 8-channel single-ended input.

MAXQ2010 from external sensors collecting data can be stored in backup battery-powered RAM or internal flash memory. On-chip clock based on real-time 32kHz (RTC) in the stop mode can work, according to the timescales for the data provider. If you want users to enter data or information that is displayed to the user is able to achieve MAXQ2010, it has a set of general purpose input/output pin (the largest packaging has 56), you can drive LED, read the mechanical switch settings, or scan through the ranks of the connected switch matrix. MAXQ2010 also has an LCD controller, you can direct drive 3V-segment LCD that supports up to 1/4-cycle multiplexing (COM1-COM4), its largest package provides 40 specialized driver pins, in 4 times the multiplex mode can drive 160 segment LCD display.

The data recorder based MAXQ2010 design examples

Like many used to collect or store data in the electronic device based on the data recorder adopts MAXQ2010 USB interface with the host (PC) communication.

However, because no USB interface MAXQ2010, we use FTDI FT232R chip company achieve USB adapter with UART.