Gen 3.2 MACRO reference page

From Seamonster

Gen 3.2

• General                           Microservers, Vexcel Microservers, Quick Reference, Data Acquisition, Middleware
• Components                   GPS, SBC
• Configuration                   Microserver, SBC, SD Card, Power
• Operation                       Communication Protocol (SBC <--> uc), SBC Operations, Agent
• Operation (background)   Task Manager "milo", config files, MACRO
• Microcontroller                 Microcontroller, Firmware, Skeleton firmware
• Evaluation                       2008 Cairn relay failure evaluation, Lab evaluation, Eval-Firmware, BPMS, Source notes
• PCS Board                     PCS Board Design, Voltage Monitoring Circuit

Gen 3.1

• Gen 3.1 Kernel Upgrade and Field Notes (Spring 2007)
• Gen 3.1 Microserver, README, Schematics
• Gen 3.1 Task Manager "milo", GPS, Firmware

Microcontroller-related

• Power Management / Microcontroller documentation, Instruction Set, General Purpose I/O (GPIO)

Other Microserver-Related

• Project Technical Notes, Microserver GPS, EmStar

Introduction

This page responds to To Do items generated in the course of the MACRO collaboration.

Dipa's Memo 1/17/2008

Microserver Operational Modes can be combined

• Basic mode descriptions
  • All On
  • Radio Quiet: SBC up, Bridge off
  • Timed Hibernate (due to planned duty cycling)
  • Power Hibernate (due to insufficient external supply voltage)

• State modifiers
  • GPS Off/On
  • SBC Normal Power / Low Power
  • SBC USB Off/On
  • SBC Ethernet Off/On
  • Mote Basestation Off/On

• Example Configuration modifiers
  • External power battery/line/other
  • External charge PV/line/other
  • External supply 12/5/3.3 110 (i.e. 12V in use, 5V in use, 3.3V not in use)
  • External USB Engaged
  • External Ethernet Engaged

The configuration modifier list is potentially quite long; let's see how much detail becomes necessary (for example to specify jumper configurations on the power board) before belaboring this further.

Duty cycling

The following current/power values are off of a 12V supply. Both the charge controller and the voltage reg draw power which creates a vampire drain even when the device hibernates.

• Off 0.036 amps (0.43 watts; this power supply draw, not PCS)
• PCS 0.055 amps (0.66 watts; additional 0.23 watts drawn by PCS board)
• GPS 0.116 amps (1.4 watts)
• WET 0.610 amps (7.3 watts [sic])
• AMP 0.180 amps (0.12 watts)
• SBC 0.240 amps (2.88 watts)

Power state measurement

The external voltage can be sampled as often as once per second. The measurement is made by the PCS microcontroller and can be returned to the SBC as either push or pull.

• Push: Signal an interrupt to an SBC Listen process; e.g. if a low voltage threshold is reached
• Pull: SBC does a voltage request interaction with the uC; e.g. if an agent is watching for a trend.

120 minutes

This time limit was chosen as a balance between a "decent" GPS time acquisition and a failsafe strategy: No matter what the SBC does (or what hang state it enters) the uC will reset the system every 130 minutes. This time interval can be controlled in firmware and can be disabled.

Microserver knowledge of date/time

Each Microserver SBC has a Real-Time Clock (RTC) backed by in internal lithium battery. This means that when the system boots it will know date and time to within minutes. As a back-up, the GPS can be used to determine same per gps.c. Based on deployment latitude a solar illumination estimate can be generated that covers the year. In a previous deployment the year was divided into seven intervals with corresponding duty cycles.

Sunlight

Two methods to detect: First on the microserver a strong illumination of the solar panel will produce a corresponding excess voltage which should be readable by the uC. Second, motes have onboard PAR/TSR light sensors. Development is needed in both cases.