smartMeter
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Contrary to the other smartDevices, the smartMeter is an autonomous device. It doesn't require any connection to the RoboTX controller as it features its own display.
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Large fischertechnik models include many motors and lamps and reach high power consumption. A simple bulb lamp requires up to ~100 mA and 1 W.
So total consumption can quickly outreach the capacity supplied by the battery pack or the AC power adaptor. This project provides a handy tool to get precise measures:
The smartMeter keeps minima and maxima for each of the three measures. A push-button allows to change unit, clear the minima and maxima, and change the decimal separator between point and comma. As usual, the module is cased on a 9V red box for a nice integration. |
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The different screens, from left to right: splash screen, measures in mV-mA-mW, measures in V-A-W with point and comma as decimal separator.
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Selecting the function with the push button, from left to right: ./m. change of units, =0 reset, ., decimal separator, __ cancel.
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The smartMeter uses an INA219 as sensor and a MSP430 as MCU. The project is described at the Embedded Computing website.
Thanks to its built-in regulator, the smartMeter can be powered with 5–16 V. The measure range is wide enough for fischertechnik models, up to 26 V and 3 A. The I²C Voltage-Current-Power INA219 Sensor provides the three measures, so there's no need for multiplying voltage by current to obtain power. |
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