- on Test & Measurement
ConclusionsIt's important to note that the Arduino ProMini board was packed with the Otii Arc kit for review and quick demoing only-- it is not a regular part of the Otii Arc set. As minimal criticisms of the demo set only, I would mention the lack of a proper description of what the Arduino ProMini is doing exactly besides flashing its onboard LED. The demo obviously measures the peak current draw of the little board and unsurprisingly reveals that the LED steals most if not all of the power, although the on time and initialisation of the processor can be seen too! Food for programmers! The very positive crux though of the demo is in the exact pinpointing of the current peaks, and being able to prove that battery power (if used on the Arduino as a virtual IoT device) can be extended considerably by dropping the supply voltage to say 3 volts. The system instantly displays cumulative energy consumption E in picowatt-hour (yes, pWh), instantaneous and peak currents. Very convincing.
On shortcomings, these are minimal and concern minor hardware issues only. First, no cable is supplied to power the Arc box through its 7-9 VDC barrel socket. Second and more annoying, but again only relevant to the Demo kit I reviewed, the little cable to connect the Arc RX pin to the Arduino ProMini TXD pin has a pin at one end, and a receptacle at the other, when in fact receptacles are required at both ends. I solved this by using a test lead from a Tektronix 1978 (!) oscilloscope field service kit.
This is an exciting kit for an, admittedly, niche market: those of you after the last nanoamps of power that can be saved to keep an IoT device alive. Or optimise battery charge/discharge processes (the premium version of Otii Arc comes with a battery simulator extension). Compared to a USB scope, a shunt, an adjustable supply and a data logger, the Otii Arc is a compact and exquisitely portable unit. Its price of €399 plus VAT (valid until May 31st 2018) I find steep though, and pro users also face a €399 annual license fee for extra features & premium tech support. Your Product Development Manager may laugh at the total investment though, once he sees your chart-supported deep analysis of “the battery problem” on his screen.
This is an independent review. I have no commercial or contractual affiliation with Qoitech.
About Jan Buiting
Jan Buiting (1958) has been active in electronics and ways of expressing it since the age of 15. Attempts at educating Jan formally have so far yielded an F-class radio amateur license, an MA degree in English, a Tek Guru award, and various certificates in ele... >>