The design for a brow thermometer encompasses a microcontroller with ADC, energy administration, and connectivity for healthcare purposes.

The reference design from NXP semiconductor for a brow thermometer is predicated on the K32L2B microcontroller. It’s a refined resolution tailor-made for cost-sensitive and low-power battery-operated purposes. This design is centred round a 48 MHz ARM Cortex-M0+ core and helps 256K flash reminiscence, making it highly effective but environment friendly. The MCU collection stands out with its wealthy mix of analogue peripherals and digital interfaces, geared explicitly in the direction of purposes the place minimising value and energy utilization is essential.

One of many key options of this design is its built-in multi-channel 16-bit ADC (Analog-to-Digital Converter). This ADC is essential for accumulating indicators from the infrared temperature sensor and measuring battery voltage. The accuracy ranges of the MCU’s ADC are fairly excessive, reaching 13.9 bits in single-ended mode and 14.5 bits in differential mode. Such precision permits the thermometer to succeed in a powerful temperature measurement accuracy of 0.1 levels.

The design additionally features a 12-bit DAC (Digital-to-Analog Converter), which offers bias voltage to exterior operational amplifiers. This DAC negates the necessity for an exterior degree conversion chip, and it may well additionally provide a 1.2V reference voltage with a load capability of 1 mA. Moreover, the design incorporates a low-power SLCD (Phase LCD) show, supporting 24×8 or 28×4 segments. The SLCD pins are versatile, functioning as section and customary ports or for different IO features.

Connectivity on this design is enhanced via the inclusion of three I2C channels. These channels are configured such that one connects to an infrared digital sensor or proximity sensor, one other to a high-precision digital temperature sensor just like the PCT2075, and the third, utilizing FlexIO, could be arrange for normal I2C, UART, or SPI communications. Moreover, the design makes use of PWM (Pulse Width Modulation) for driving LED indicators or buzzer alarms and might assist voice playback features.

The USB interface is one other spotlight, that includes a USB FS 2.0 gadget interface that operates with out an extra crystal. Relating to reminiscence and energy effectivity, the K32L2B11VLH0A variant with 64K flash and 32K RAM is especially fitted to brow thermometers. It reveals low energy consumption in operation and deep sleep modes and has a quick wake-up mode of lower than 10 microseconds.

The 64K flash capability adequately meets the storage necessities for calibration parameters, voice knowledge, and extra. The MCU collection additionally presents a variety of product roadmaps, supporting full pin perform compatibility and the choice so as to add new options like Bluetooth and QR code scanning.

The design features a built-in ROM bootloader, immensely helpful for on-line upgrades and temperature parameter calibration. The built-in high-precision inner clock is important for manufacturing unit firmware manufacturing.

NXP Semiconductor has examined this reference design. It comes with a Invoice of Materials (BOM), schematics, and so on. You could find extra knowledge concerning the reference design on the corporate’s web site. To learn extra about this reference design, click on right here.