Owl Power Management
Contents
OpenCR References
Power Connection Hardware
Goal: Connect the NUC to the 12V output source used by the Joule in the original TB3 Waffle. This is a reasonable possibility because the NUC uses an amp when lightly loaded which is well within the the 3 amp spec for power input to the Joule.
- The Joule 570x development kit
- Online Guide for the Intel® Joule™ Module Development Kit Overview
- Uses 2.1 mm inner diameter (positive)
- 5.5 mm outer diameter (negative)
- 12 v 3 amps
- Intel NUC Board D54250WYB
- Intel NUC Board D54250WYB and Intel NUC Board D34010WYB Technical Product Specification H18263-007 May 2017 page 48 (page 55 also has some information about power requirements)
- 5.5 mm outside diameter
- 2.5 mm inside diameter
- 12 - 19V
- I connected the Intel NUC to the OpenCR 12V out using the cable supplied with the Joule Waffle and an adapter I designed for the NUC. (The inside pin for a NUC is 2.5mm and for a Joule is 2.1mm.) This is the same power output jack that is used for the Joule.
Baseline Test
Goal is to get the baseline current used by the OpenCR when it is not powering the NUC.
- The NUC is powered by its brick.
- A bench power supply is set to 11.1 volts and connected to the 11.1 V battery input of the OpenCR.
- The lidar was connected to the NUC
| OpenCR 11.1V at Battery - Not powering NUC | |
|---|---|
| State | Current Amps |
| Off | 0 |
| Booted | 0.22 |
| NUC Booted | 0.22 |
| Post Bringup | 0.22 |
| Motors running full no load | 0.34 |
OpenCR Powered NUC
- The Intel NUC is connect to the OpenCR 12V out using the cable supplied with the Joule Waffle. The adapter describe above is used to adapt the Joule cable to the NUC.
- I connected a bench power supply to the battery input and set set it to 12 V.
- The lidar was connected to the NUC
Note: If the bench supply is set to 11.1 V the OpenCR's low voltage buzzer will go off. This didn't haven in the prevous test. I suspect there is some internal resistance someplace that is causing a voltage drop. Setting the bench power supply to 12 V solved the problem. I suspect the 11.1 V parking on the battery input label is to define the battery rating. Not the input voltage. The OpenCR expectation is to have the bench power supply connected to the SMPS (Switch Mode Power Supply input jack. However, I was interested in understanding the power requirements of the battery and the bench power supply allowed me to set the voltage and read the current draw.
| OpenCR 12.0V at Battery - plus NUC | ||
|---|---|---|
| State | Peak Amps | Steady State |
| Off | 0 | 0 |
| Booted - NUC booting - lidar turning | 1.9 | 1.8 |
| NUC Booted with lidar | 1.43 | 0.77 |
| Post Bringup | 0.9 | 0.84 |
| Post keyboard teleop | 1.45 | 0.9 |
| Motors running full no load (0.26 M/sec) | 1.03 | 0.97 |
| Powered down NUC | 0.22 | 0.22 |
LiPo Batteries
Specs
- 11.1V 3s
- Dean's connector
- 1800 mAh: Original
- 2200 mAh: 25C: Floureon replacement
