Problems Powering a Lidar-lite v3HP from a boost module

Sensors Distance
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There are ongoing problems with incorrect ranging, when trying to power the lidar-lite V3HP from a 3.6 volts, non-rechargeable, long life, battery (Lithium Thionyl Chloride Cylindrical D Cell and also a Saft 14500) boosted to 5 volts, using various off-the-shelf boost and also step-up/step-down modules with disable modes that can be controlled via an mcu. The minimum voltage input for these DC-DC modules is specified at around 3 volts (actually we also tried one with 1.5 volts minimum with same issue), so in theory there should be no problem. Current output should in theory easily be sufficient. Strangely there is no ranging problem with voltages above about 3.7. However that leaves us with a problem trying to use long life, non-rechargeable batteries for a key project. Their 3.6 nominal voltage will drop to 3.5 over time and under load.

We have noticed that the non-ranging current draw when the lidar-lite V3HP ranges correctly is 60+mA. I haven’t yet measured the ranging current as it is very rapid. Will need to setup something with a scope. However when a boost module input voltage is below 3.7, the current draw is around 58 or 58 mA, this is despite unit being driven at 5 volts or very close to 5 volts as measured. In that case the unit returns completely incorrect ranges, e.g. 100s of centimeters or near zero.

So not really sure yet what is going on or why the lidar-lite v3HP seems so unforgiving with these boost modules. I’ve checked power line noise in case this was increasing as the voltage reduced with the modules working harder to achieve 5 volts but there is no significant noise difference from lower to higher boost module input voltages.

There is a 1000uF capacitor across the lidar-lite v3HP +ve and -ve lines, i.e. somewhat higher than recommended, which I’m assuming should make no difference.

We need to use a boosted, long life battery for the project, as 2 batteries in series would mean too high voltage for other electronics, whilst a buck module capable of supporting the total current required would introduce too high quiescent current.

Suggestions would be appreciated.

Best wishes, Ron

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Hey Ron,

My best guess is that it might be your power supply (the boost module) is not sourcing enough current or providing a stable 5V output. Based on the [operation manual by Garmin, the Lidar-Lite draws about 65mA in idle and 85mA during an acquisition. Additionally, it notes:

Connecting the device to a source greater or less than 5 Vdc is not supported and may result in poor performance or damage to the device.

If you want to test to see if your Lidar is working, I would use the setup recommended in the operation manual or our [hookup guide. If you find that the Lidar-Lite isn’t working, let us know so we can try to troubleshoot the Lidar-Lite. Otherwise, then you can start investigating the boost module. Another option for using batteries is to put them in series and use a voltage regulator or DC-DC converter to drop the voltage down to 5V. This is usually more reliable than a buck or boost converter.](LIDAR-Lite v3 Hookup Guide - SparkFun Learn)](http://static.garmin.com/pumac/LIDAR-Lite_v3HP_Instructions_EN.pdf)