EnvironOne - Light, Humidity, Temperature and barometric pressure all in one
This is the EnvironOne module, a module designed specifically with room monitoring in mind. EnvironOne is populated with a light sensor, temperature sensor, humidity sensor and a barometric pressure sensor. All of these sensors combined will give your system a complete picture of the environment in the surrounding area of your system.
The board is fairly simple in its design by using two highly integrated sensors to do all the measurements.
The Light Sensor
To do the light measurements the OPT3001 sensor is used. This device was selected due to its tight matching to the photopic response of the human eye and that it significantly rejects infrared light. The OPT3001 is a single-chip lux meter, measuring the intensity of light as visible by the human eye. The precision spectral response and strong IR rejection of the device enables the OPT3001 to accurately meter the intensity of light as seen by the human eye regardless of light source. The strong IR rejection also aids in maintaining high accuracy when industrial design calls for mounting the sensor under dark glass for aesthetics.
Measurements can be made from 0.01 lux up to 83k lux without manually selecting full-scale ranges by using the built-in, full-scale setting feature. This capability allows light measurement over a 23-bit effective dynamic range.
An Arduino library for accessing the light sensor can be found at https://github.com/Sweet-Peas/OPT3001
The Temperature/Humidity/Barometric Sensor
The rest of the measurements are performed by a device called BME280. The BME280 achieves high performance in all applications requiring humidity and pressure measurement. Emerging applications of home automation control, in-door navigation, health care as well as GPS refinement require a high accuracy and a low TCO at the same time. The humidity sensor provides an extremely fast response time for fast context awareness applications and high overall accuracy over a wide temperature range. The pressure sensor is an absolute barometric pressure sensor with extremely high accuracy and resolution and drastically lower noise than the Bosch Sensortec BMP180. The integrated temperature sensor has been optimized for lowest noise and highest resolution. Its output is used for temperature compensation of the pressure and humidity sensors and can also be used for estimation of the ambient temperature.
An Arduino library for accessing the BME280 can be found at https://github.com/Sweet-Peas/BME280
The board have two jumpers that you need to consider before using the board. The first one is SJ1. this jumper connects the interrupt output from the OPT3001 sensor to pin GPIO12 of the ESP210. The current Arduino libraries does not rely on having this jumper closed but if your are developing your own software you might consider closing this jumper.
The second jumper, SJ3, connects a pull up resistor to the SCL signal. The ESP210 does not have a pull up resistor connected to the SCL output so this need to be arranged externally. Most +One modules have a solder jumper that will enable this pull up resistor. You can only have one board with this jumper closed. So if you have a node.IT stack with several I2C boards you need to ensure that only one of these boards have the SCL jumper shortened.
SJ4 is used to select a specific pin for the SCL function. By default this is connected to GPIO14 but if you are building a system that requires the use of GPIO14 for something else, such as the SPI interface for instance, you can configure this jumper to select pin GPIO0 instead. This way you can have both SPI and I2C running in your system.
The jumpers are PCB level jumpers that need to be closed using a solder blob. This is very easy to obtain, simply heat your solder iron and melt the already existing solder on the pads of the jumper. Then apply as much solder you need to close the gap between the pads. When you need to remove a solder jumper you simply take your solder braid, heat the braid and the solder and wick the solder away.
When running the ESP210 from a USB supply, the linear LDO on the board will get a little warm. If the EnvironOne is connected directly on top of the ESP210 the heat generated from the LDO will affect the measurement results. If you want to have the EnvironOne connected directly on top of the ESP210 we recommend that you run the ESP210 from a separate 3.3 volt power supply connected to the 3.3V pin.
The best results can be achieved by running the system from a 3.3V supply and then putting the ESP210 in deep sleep mode between measurements.
- Library for accessing the OPT3001 sensor
- Library for accessing the BME280 sensor
- OPT3001 Data Sheet
- BME280 Data Sheet
- EnvironOne Schematic