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--- mission:tech:odyssey:sku [2012/06/29 08:21] – [Software] chrono
+++ mission:tech:odyssey:sku [2014/11/22 19:22] (current) – [Station Keeping Unit (SKU)] chrono
@@ Line 1: / Line 1: @@
+====== Station Keeping Unit (SKU) ======
+[{{ :mission:tech:odyssey:foxg20.jpg?270|Fox/Netus G20 with Atmel AT91SAM9G20}}]
+The purpose of the SKU is to monitor, analyze and control all of Odyssey's subsystems as well as to provide mandatory system features:
+  * Positioning
+  * Precision Time-Keeping
+  * Power controlling
+  * System-Alerting/Monitoring
+  * Basic Vehicle Operating & Module-Communication System
+It will also monitor and record habitual & mobile environmental parameters (external/internal), in order to develop power consumption/harvesting profiles which may propose either a change in power usage behaviour or a change in power harvesting methods so that we can maximize efficiency and prolong battery live by reducing charge/discharge cycles. In short, all designated house- and station-keeping tasks will be controlled by this unit.
+It is meant to be always kept powered on, so the power consumption budget of the SKU is very demanding. The Goal was to deploy a system that will not draw more than 1-2W in full system operation mode, the current implementation of the SKU draws **less than 1W**, running Gentoo-Linux, gpsd, chrony, collectd and USB/SD data storage units.
+~~CL~~
+=====Hardware platform=====
+After researching different embedded solutions the choice went in favour of the Acme-Systems Netus G20 system, with an ATMEL AT91SAM9G20 400MHz ARM9 CPU (max. 50mW@25°C = 0.125mw/MHz) and 64MB/1.8V BGA SDRAM(532MB/s), to reduce power comsumption and due to the mobile nature of the SDRAM, enabling low power modes, claiming a total of 80mA@5V (0.4W) idle power consumption. Although the Cortex A5 offers more than twice the DMips/W amount, the broader availability, the price and the available amount of documentation on the internet lead to the Netus G20, produced by Acme-Systems, Italy. It was also considered to use an ATMega32 as SKU but the idea was abandoned because a real Linux can offer more features off the shelf and seems a much more flexible solution than to reinvent everything on a uC level. Temperature range: -15 to +70 Celsius degree (°C).
+\\
+^CPU^Mhz^DMIPS^mW^mw/Mhz^DMips/Watt^Used in^
+|Intel Atom N270|1600|4000|10000|6.3|400|low-end miniitx / netbooks|
+|Intel Atom Z515|1200|2500|3600|3.0|830|mid-range netbooks/miniitx /w US15W |
+|Arm9 old|200|220|260|1.3|830|Smartphones, embedded boards, routerboard|
+|**Arm9 new**|400|450|50|0.13|**5500**|Smartphones, newer embedded boards, FOX G20|
+|Arm11|600|780|360|0.6|2000|Smartphones, iPhone 3G|
+|Arm Cortex A8|1100|1500|500|0.45|3500|Smartphones (3GS), netbooks|
+|**Cortex A5**|480|700|60|0.12|**13000**|Smartphones NG|
+|AVR32|150|210|150|1.0|1400|embedded (atmel/avr) boards|
+=====Operating System and Software=====
+The underlying Operating System will be Gentoo with a custom portage tree for the individual house- and station-keeping modules. The Development and compilation shall be done in a chroot container either on the MCU when mobile or the HP DL380 when stationary and on-grid, for fast deployment.
+  * Chrony
+  * GPSD
+  * TPV Logging
+  * Watchdogs
+  * CollectD
+For more Info about the SKU Software go [[mission:tech:odyssey:sku:software|here]]
+===== Station Keeping Runlevel =====
+  * Mobile
+  * Stationary Off-Grid
+    * Offline
+    * Online
+      * Hibernating
+      * Basic Operation
+      * Full Operation
+  * Stationary On-Grid
+===== External Peripherals =====
+{{:mission:tech:odyssey:sku-block.png?560|}}
+The SKU gathers relevant performance/environment data, provides mandatory network services and controls the system mostly through external periphery, which has to be kept modular in order to
+  * leave room for future optimization
+  * maintain overall system funcionality - in case of single module malfunction
+  * modules can be used otherwise when the system doesn't need it
+  * keep power consumption low by only supplying power to active modules
+  * off the shelf usb modules have a bigger chance to be quickly replaced on the road in different countries
+^Name^Connect via^U^I^Purpose^
+|Rockwell/Connexant Jupiter TU30-420-031|3.3V Serial + DCD|3.3|0.15|Time & Frequency 10 khz -> GPS disciplined clock/10MHz OCXO|
+|uBlox LEA-6T|3.3V Serial + DCD|3.3|-|Time & Frequency GPS disciplined clock/10MHz OCXO|
+|uBlox LEA-6R|3.3V Serial RX-only|3.3|-|PV + Dead-Reckoning|
+|CUL-868|USB|5|?|ISM 868 MHz Mastercontroller|
+|USB UMTS/GPRS (PrePaid)|USB|5|?|Failsafe Datalink|
+|USB WLAN 802.11a/g/n?|USB or SPI|3.3|?|Primary Datalink|
+|PDU sensor input|3.3V Serial RX|3.3|?|Log PDU sensor data|
+|PDU switch output|3.3V Serial TX|3.3|?|Switch Power buses|
+|DS1820 Tempsensors|1-Wire|3.3|0.001|Temperatur sensor Bus (-55/+125°C@9-12bit)|
+==== GPS ====
+It was more by accident than intention that I was able to get one of the old Rockwell/Connexant Jupiter TU30-420-031 GPS receivers on eBay. The earlier plans involved 2 GPS Systems, one for PV (Position/Velocity) and one for TF (Timing/Frequency) purposes. They were also supposed to back each other up (one module fails, the other will take over PV or TF duties as secondary system).
+As it turned out the TU30-420-031 is not only capable of supplying the rare GPS disciplined 10kHz frequency output feature, I originally wanted it for, but it is also capable of dead-reckoning. Even when satellite reception is lost due to a tunnel/building, the gps will measure the speed/distance, given by the car's wheel sensor ticks and the rotation around the z-axis (going left/right) by measuring the analog output of a gyro sensor (ADXRS610). The driving direction (for/rev) is also taken into account, I guess I'll take the reverse-light power as input for this.
+Altough I cursed myself at first for buying a 3.3V model, I came to realize how lucky I've been. Since the SKU base board is a 3.3V model I hooked it up directly to ttyS1 (RX/TX and PPS on DCD) - ttyS1 is the only serial interface on the Netus G20, that supports all serial pins (including DCD). Although there are patches to use CTS as PPS input I opted for DCD.
+The only problem with 3.3V was, that the GPSDO had to be redesigned to work with the 3.3V 10kHz frequency to PLL sync the OCXOs 10MHz ouput.
+The GPS module is responsible for the following features:
+  * GPS PV Data for navigation subsystems (GPSD)
+  * Dead-Reckoning PV data for navigation systems (GPSD)
+  * Stratum 1 time sync capabilities (Chrony/Kernel)
+    * Kernel PPS through DCD
+    * Chrony GPSD socket sync (nanosecond deviation)
+  * 10kHz GPS disciplined frequency (->GPSDO Module)
+[{{:mission:log:2011-09-27:jupiter_chrony_time_offset_utc.png?295|Ref. Time-Offset to UTC}}]
+[{{:mission:log:2011-09-27:jupiter_gps_visible_sats.png?295|GPS - Visible Sats}}]
+[[apollo:hardware:sku:jupiter]]
+==== RNG ====
+http://www.jtxp.org/tech/XR232circuit_v20_HiRes.gif
+==== IMU ====
+===Accelerate===
+===Gyro===
+===Compass===
+Honeywell tilt compensated MEMS Compass Module HMC4363
+===== Interfaces =====
+==== Software ====
+  * SKU <-> [[mission:tech:odyssey:mcu|MCU]] (tcp)
+  * SKU <-> [[mission:tech:odyssey:pdu|PDU]] (RS232 <-> PDU Daemon in python)
+=== Position to Timezone Tracking ===
+Apollo-NG's primary clock is always UTC. As a moving element, we will pass through different local time zones, we should be aware of. When passing a timezone boundary, Apollo-NG will notify the crew and change the secondary clock (localtime) according to the current timezone (including correct DST offsets as well).
+[[mission:tech:odyssey:sku:position-to-timezone]]
+=== Solar-Output prediction model ===
+[[lab:ucsspm]]
+==== User ====
+  * Button-panel with led status on/off
+  * Display (budget dependent)
+===== Notes =====
+==== SKU - EN/IEC 60603-2C Header ====
+The following table is a documentation of the latest Netus/Foxboard G20 connections to the 60603-2C (DIN 41612) Header (96-Pins):
+^ FOX ^ PIN ^ Description ^  A  ^  B  ^  C  ^
+| J6.08 | RXD0 | Receive GPS data on ttyS1 |  23  | | |
+| J6.09 | TXD0 | Transmit data ttyS1 | |  23  | |
+| J7.31 | DCD0 | PPS0 Timepulse input | | |  23  |
+|J6.15 | RXD5 | Receive PDU data ttyS6 |  4  | | |
+|J6.16 | TXD5 | Transmit PDU data ttyS6 | | |  4  |
+| J6.30 | AD0 | Analog input 0 |  28  |  28  |  28  |
+|  | 1W VCC | OneWire VCC |  1  |  |  |
+|  | 1W DATA | OneWire DATA |  |  2  |  |
+|  | 1W GND | OneWire GND |  |  |  3  |
+|  | Sys VCC | System VCC |  28  |  28  |  28  |
+|  | Sys GND | System GND |  26  |  26  |  26  |
+| J7.40 | Sys 3V3 | System 3V3 |  32  |  32  |  32  |

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