[ST MEMS waterproof pressure sensor LPS27HHW review] + First impression of LPS27HHW

jinglixixi

[ST MEMS waterproof pressure sensor LPS27HHW review] + First impression of LPS27HHW [Copy link]

 

 

The LPS27HHW function board is a waterproof pressure sensor from the ST MEMS family. It is an ultra-compact piezoresistive sensor that can be used as a barometer with digital output. The device consists of a sensing element and an IC interface that communicates via IC, MIPI I3CSM or SPI. The sensing element detects absolute pressure and consists of a suspended membrane manufactured using a dedicated process developed by ST.

The specific features of LPS27HHW are as follows:

• Pressure sensor in waterproof package
• Potting compound and grounding metal cap
• Absolute pressure range: 260hPa to 1260hPa
• Current consumption as low as 4μA
• Absolute pressure accuracy: 0.5hPa
• Low pressure sensor noise: 0.7Pa
• Built-in temperature compensation
• 24-bit pressure data output
• ODR: 1Hz to 200Hz
• SPI, IC or MIPI I3CSM interface
• Built-in FIFO
• Interrupt functions: data ready, FIFO marker, pressure threshold
• Supply voltage: 1.7V to 3.6V
• Meets ECOPACK lead-free requirements

The appearance of the LPS27HHW function board is shown in Figure 1, and its schematic diagram is shown in Figure 2.

From this we can see that although there are many pad holes on the functional board, only 8 or even fewer are actually used.

Figure 1 LPS27HHW function board

Figure 2 Function board schematic diagram

The purpose of the relevant pins is as follows:

Inside the LPS27HHW, the processing flow is shown in Figure 3. It uses a bridge to increase the amount of physical signals, and transmits two analog signals to the ADC converter for conversion through a multi-way switch, and then transmits the digital signals through interfaces such as I2C and SPI.

Figure 3 LPS27HHW processing flow

From the relevant driver code, it is based on the NUCLEO_STM32F411RE development board. Later, we will follow this path to test the functions of LPS27HHW and configure the corresponding OLED screen for it to realize the intuitive display output of the air pressure measurement value.

Related references include:

LPS27HHW Datasheet:

lps27hhw.pdf(1.31 MB)

LPS27HHW Application Notes:

LPS27HHW MEMS pressure sensor with water-resistant package en.DM00650819.pdf(530.86 KB)

LPS27HHW driver code:

lps27hhw_STdC.rar (10.71 KB)

w494143467

How should this sensor measure performance?

jinglixixi

w494143467 posted on 2020-12-16 13:16 How should this sensor measure performance?

Generally speaking, performance testing is a professional matter and we have nothing to do with it, but this air pressure sensor is a digital sensor, which means we don't need to worry about the nominal value. The default values are all instrument-level, and we can read the measured values of the sensor in the application. If we have high-level related instruments, we can also test and analyze the results obtained by the sensor. We are application personnel, and our superficial understanding is only to this extent. Professionals may have different textbook answers.

w494143467

jinglixixi posted on 2020-12-16 18:51 w494143467 posted on 2020-12-16 13:16 How should this sensor measure performance? Generally speaking, performance measurement is professional-level...

Got it, then just measure some of its basic performance~

jinglixixi

w494143467 Published on 2020-12-16 18:55 Got it, then just measure some of its basic performance~

That's what I mean

ddllxxrr

The review photo is quite large, but it is actually not that big.

jinglixixi

ddllxxrr Published on 2020-12-16 21:48 Review The photo looks quite large, but it’s actually not that big.

How big can 2.7*2.7*1.7 mm be!

申小林

The attachment cannot be read……………………

nmg

Shen Xiaolin posted on 2020-12-17 09:06 The attachment cannot be read……………………

Now, you try it.

ddllxxrr

jinglixixi posted on 2020-12-17 00:18 ddllxxrr posted on 2020-12-16 21:48 The evaluation photo is quite large, but it is not really big. How big can 2.7*2.7*1.7 mm be...

Should it be as big as the photo?

jinglixixi

ddllxxrr posted on 2020-12-17 12:26 Should it be as big as the photo?

Haha, let’s see how it performs later!

freebsder

Is the U1 a sensor? Is it waterproof? I want to try to measure the water pressure after reading your reviews.

jinglixixi

freebsder posted on 2020-12-17 21:39 Is the U1 thing a sensor? Is it waterproof? After reading your reviews, I want to try to measure the water pressure.

Judging from the information, it has waterproof properties and uses suspended membrane technology. As for whether the pressure it can withstand is the same as the measured pressure range, it is hard to say and actual trial is needed.

freebsder

jinglixixi posted on 2020-12-18 00:15 From the data, it has waterproof performance. It uses suspended membrane technology. As for whether the pressure it can withstand is the same as the measured pressure range, it is hard to say. It needs to be actually tested...

Thanks, I'll watch you guys play first.

littleshrimp

jinglixixi posted on 2020-12-18 00:15 From the data, it has waterproof performance. It uses suspended membrane technology. As for whether the pressure it can withstand is the same as the measured pressure range, it is hard to say. It needs to be actually tested...

jinglixixi

littleshrimp 发表于 2020-12-18 13:35

meticulous!!!

tagetage

The accuracy, power consumption and size are all very impressive, but I don’t know how long it will last.

jinglixixi

tagetage posted on 2020-12-19 17:19 The accuracy, power consumption and size are all great, but I don’t know how long it will last.

Insightful questions that can only be answered in time.