This week, we're announcing two new additions to the list of Yoctopuce modules available with USB-C connectivity: the Yocto-SDI12-C and the Yocto-Temperature-IR-C.
Yocto-SDI12-C
Although little known to the general public, SDI12 is a protocol widely used in the field of agricultural sensors. This protocol uses a three-wire serial bus, including the power line, and emphasizes long-distance communication and low power consumption. However, compared to more common wired communication systems, it is quite slow: around 1200 baud.
The Yocto-SDI12-C can act as a master capable of polling all sensors on the SDI12 bus. It can even automatically inventory the sensors present on the bus. It can also act as a sensor that transmits data when polled. There is a third operating mode: it can simply passively listen to the data passing through the bus, which can be very useful when you need to understand what is happening on a bus that is behaving somewhat unexpectedly.
The Yocto-SDI12-C
Technically, one of the challenges of interfacing with an SDI12 bus is the fairly tight timing requirements imposed by this protocol. In the case of the Yocto-SDI12-C module, these timings are fully managed by the module, which may not be the case with a simple SDI12-to-serial converter that you might find for next to nothing on the market.
Like all Yoctopuce modules that manage serial buses, the Yocto-SDI12-C offers a system of autonomous jobs that allow you to query SDI12 sensors and present the results in the form of classic Yoctopuce sensors, with all the advantages this entails: data logger, callback programming, compatibility with Yocto-Visualization, and so on.
The USB and SDI12 parts of the Yocto-SDI12-C are separated by functional isolation, which should protect you from electrical mishaps that could potentially be caused by the very long wires of an SDI12 bus.
At CHF 87.20, the price of the Yocto-SDI12-C is quite similar to that of the Micro-B version, which was lowered a few weeks ago.
Yocto-Temperature-IR-C
The Yocto-Temperature-IR-C is a temperature sensor based on a MELEXIS MLX90614ESF-DCA infrared sensor that can measure temperatures ranging from -70 to 380°C. Its main advantage is, of course, the ability to measure temperature without contact. In addition to the temperature measured by infrared, the Yocto-Temperature-IR-C can also measure the ambient temperature.
Apart from that, it behaves exactly like a standard Yoctopuce temperature sensor: measures in °C, °F, or Kelvin, and a built-in data logger. The measuring part of the module can be separated from the USB part of the module. The Yocto-Temperature-IR-C is sold with a single MELEXIS MLX90614 sensor, but the firmware supports additional MLX90614 sensors wired in series with the original sensor. You can find more information about this feature in the Yocto-Temperature-IR-C documentation.
The Yocto-Temperature-IR-C
Using the Yocto-Temperature-IR-C is intuitive; simply point it at the object to be measured, keeping in mind that the sensor returns the average temperature of everything within its field of vision, which has a 90° aperture. Also be careful with reflective surfaces: you can quite easily end up measuring the temperature of a reflected object rather than the temperature of the surface itself. Also be aware that you cannot use the Yocto-Temperature-IR-C as a medical device to determine whether someone has a fever or not.
After calculating the price of the Yocto-Temperature-IR-C at CHF 70.50, that is three times the cost of its components, we decided to lower the price of the Micro-B version to CHF 70.30 to maintain some consistency.
