Life has its ups and downs, so why not measure them? The MPL3115A2 is a MEMS pressure sensor that provides Altitude data to within 30cm (with oversampling enabled). The sensor outputs are digitized by a high resolution 24-bit ADC and transmitted over I2C, meaning it's easy to interface with most controllers. Pressure output can be resolved with output in fractions of a Pascal, and Altitude can be resolved in fractions of a meter. The device also provides 12-bit temperature measurements in degrees Celsius.
This breakout board makes it easy to prototype using this tiny device by breaking out the necessary pins to a standard 0.1" spaced header. The board also has all of the passive components needed to get the device functioning, so you can simply connect it to something that talks I2C and get to work!
This skill defines how difficult the soldering is on a particular product. It might be a couple simple solder joints, or require special reflow tools.
Skill Level: Noob - Some basic soldering is required, but it is limited to a just a few pins, basic through-hole soldering, and couple (if any) polarized components. A basic soldering iron is all you should need.
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If a board needs code or communicates somehow, you're going to need to know how to program or interface with it. The programming skill is all about communication and code.
Skill Level: Competent - The toolchain for programming is a bit more complex and will examples may not be explicitly provided for you. You will be required to have a fundamental knowledge of programming and be required to provide your own code. You may need to modify existing libraries or code to work with your specific hardware. Sensor and hardware interfaces will be SPI or I2C.
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If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.
Skill Level: Noob - You don't need to reference a datasheet, but you will need to know basic power requirements.
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Based on 15 ratings:
1 of 1 found this helpful:
The part worked good mounted on a msp430 launchpad. Used it to deploy a parachute on a water bottle rocket. Parachute deployed upon descent and it gave me the altitude.
3 of 3 found this helpful:
I'm developing a telemetry system and I've gone through some parts now and I can say this one is a good buy in terms of work with. Easy to configure but limited regarding of internal sampling configuration (custom sampling frequencies are done using one shot). I've gave a "Good" grade because I still haven't measure output (pressure/altitude) variance, offset, linearity, etc.
P.S.: If you are doing an engineering project don't forget to calibrate these things. Most are "factory calibrated" but that is the same as if they aren't. Calibration is one of the most expensive component of a sensor.
4 of 5 found this helpful:
Not a knock against this board, but it doesn't work with the Raspberry Pi. Wish I'd done my homework and figured that out first.
It's a limitation of the Pi itself, which doesn't support repeated start over the I2C bus. The BMP180 is the sensor you need if you want to use it with a Raspberry Pi.
1 of 2 found this helpful:
I am trying to figure out the experimental heights for a few of my projects, and it workers perfectly fine for that, it is off by about 2 degrees Celsius with temperature which isn't too big of an issue, the pressure reads fine, but the altitude is totally screwed up. I'm only 400 feet about sea level and it keeps giving me a number around 500-900 feet, and always changes.... I left it running for 2 days once, it started at 550 feet above sea level, and jumped up to 900, and came back down to around 600. And every time I turn it back on, it keeps starting with a different height. I don't know what is causing this. I am considering buying another one to see if I got a defected one.The changing height is a liability on my project, and slows me down.
I would of loved to give this 5 stars, but I would be a liar if I did.
Hi, Sorry to hear about your issue. Please contact our Tech Support team for assistance. We can help do a little trouble shooting and assist if a replacement is needed. https://www.sparkfun.com/technical_assistance
Arduino software worked out of the box and was quite easy to modify
The sensor is alright, I was going to use this to record the height that my model rocket would have flown, but it is a bit off. I am 1,137 feet high at my workbench, and the sensor reads about 1158.32. Also the sensor usually varies from about two feet when not in motion.
It was easy to hook up and get running following the instructions given, and the data is fascinating. I used it in a lesson for college freshmen about modeling measurements as signal plus noise plus bias. We were a letter to easily recognize the motion of the sensor up and down about 2 - 3 ft in the pressure measurements against the noise and background changes.
I received the board with two caps soldered together giving poor readings. A quick (free) replacement later and I was back in business. Using the 330 Ohm inline resistors I got readings accurate to a few feet of my location (remember to convert from altimeter pressure to absolute station pressure if using weather readings). Overall, a good board and accurate to a few Pa from my own experience.
After I hooked it up with my Arduino MEGA 2560, the temperature reading was very close to what I expected. However, the altitude was reading about 100 feet less than the GPS altitude. I was using the GPS altitude as my standard because think it's more accurate. Any ideas? All and all, I think it's a good product.
I've purchased 3 of these sensors. The first one was connected to 5V for a few minutes, and the second had been in storage for a long time so I thought maybe I had damaged them. When the sensors were at rest, their output altitude could drift by up to 30 feet in 4 minutes (although their temperature readings were just fine).
I purchased a third one nine days ago, but this sensor is no better. In 4 minutes its output drifted +30 feet, and in 10 minutes it drifted by over 80 feet.
I wondered if maybe this was an artifact of the MPL3115A2 chip, so I purchased the same sensor with a different breakout board from Adafruit. I ran both sensors concurrently and here is a graph of the resulting outputs: https://live.staticflickr.com/65535/50080620812_20222b1e08_b.jpg The Adafruit version shows some variation but is far more consistent than the brand new SparkFun board I used.
I've been chasing down this problem for over a month. Here is the SparkFun forum thread I started for it: https://forum.sparkfun.com/viewtopic.php?f=74&t=53015&p=216413#p216413
Overall I'm extremely disappointed because the board just can't do the one thing it's supposed to do.
Bought this for a small project and hooked it up to a Spark Fun Pro Micro, had to fiddle around with the example code before I got it to work for my needs but it outputs the correct temperature and altitude and is sensitive enough for my application. Would recommend to anyone looking for a relatively cheap and small pressure/altitude/temperature sensor.
I am planning to fabricate an integrated Barometer/Altimeter and Thermometer unit. A;ll of these functions are in this unit and it just needs I2C and off you go. I took right off, I used a 6 pin header for interface and wirewrap. The chip and allare on a Protoboard and I use a laptop for now to analyze the data. I need a little timeto figure out the various tweaks for altitude etc. Fun project!
0 of 1 found this helpful:
Installed in project, seems to work well, still doing testing.
0 of 1 found this helpful:
Exactly what it says on the tin.
works fine, haven't hooked it up to my weather station yet. Stay tuned