Motherboard Specs and Notes 26 Feb 2016 Friday Dorado AUV Meeting: Ground fault sensing .Current limiting in common rails we break out Littlefuse Polyfuse max hold current: 9A Bourns: 11A Raychem: 30A ( Mouser 650-MHP30-36-T ) .Multiplexing I/O to penetrators ( provide several grounds) Iridium SBD service may become the Drop Wt watchdog .Look at I2c addressing .Opto-Isolators are power hungry ( minimize the use of them ) Quiescent draw of HiSide Switches can exceed the load ( examine the use closely ) May use the TS-4100 for CPU DC-DC Converter Temp Sensing ---0--- 27 Dec 2016 Phone convo HRH / DRT: Not all RS232 ports need to be isolated Capture a union between the CTD_Gulper and Mapper AUVs Gulper RS422 DVL has different triggering scheme than Kearfott Draw Block Diagram two different ways, or with options Some devices like Kearfott require a complex scheme: Control Comms One PPS Timing Trigger GPS data RS232i Main Bus Connection: One PPS Trigger Isolated Ground Two classes of power loads Hi Current Tailcone New style 10A max Old Style 16A max Second 10A load Kearfott draws about 2A ( Bus Voltage ) MCBH8 penetrators Check current per pin spec == 2A ? Seacon catalog says 3 Amps Motherboard I/O Connections Each penetrator goes to one or two board connectors Board connectors do not share penetrators Four Pin Connector +12V Isolated Ground +24V / Bus power Bus Ground Termination point for shield / seawater ground Serial Ports Isolated RS232 ADM3251 460kbps 2.5kV 20SOIC pkg Isolated RS422 ADM2687E 500kbps $14.05 ADM2682E 16 Mbps $15.70 half or full 5kV 16SOIC pkg ADM2587E 500kbps $11.53 ADM2582E 16 Mbps $13.64 half or full 2.5kV 20SOIC pkg Non-isolated RS232 full duplex LT1130ACSW 5 channel $7.66 28SOIC pkg TRS208CDBR 4 channel $1.82 24SSOP pkg SN75C1406DWR 3 channel $1.63 16SOIC pkg ST232CDR 2 channel $0.58 16SOIC pkg SN75155D 1 channel $1.45 8SOIC pkg Want capability to loop - back grounds Pin Example: Non-Isolated Instrument Example: 1 Tx 1 Rx 2 Rx 2 Tx 3 Iso Gnd |------------3 Gnd 4 Bus Gnd | 5 Iso 12V Gnd ----| Kearfott is more complex Needs more detailed examination Hall Effect Current Sensors How much space is required Allegro part obsolete; check TI GMW ? See recommended layout Consider shunt - based design A TI part measures V I and Temp ? Can use I2c isolators on Bus Gnd referenced measurements INA250 Internal Shunt I only Analog Out 16TSSOP pkg .201" x .260" needs external ADC LTC4151 External Shunt V and I 12bits I2c 10MSOP pkg .122" x .122" INA226 External Shunt V and I 16bits I2c 10MSOP pkg .122" x .122" MLX91205 PCB Trace I onl Analog Out 8SOIC pkg .196" x .244" needs external ADC Power Supply Design TS4100 has stand - alone 5V supply Look for minimum no - load draw Peripheral 5V supply Switch on - off capability for stand - by mode Consider an Ideal Diode at Tether power connection ( ETR ) ---0--- 9 Jan 2017 Office MTG w/ HRH Comms What is SPI voltage ... ck w/Erik == 3V3 12 Xcvrs minimum Re-configure w/ optoisolated line from CPU One FET turns on/off Xcvrs Multi-protocol RS232 / RS485 Possibilities: ADUM5401 Exar SP336E Intersil Linear Tech Maxim 3160 Number/direction of channels, power required Power Be able to switch off all except CPU Need control inputs to be Isolated BUS V +12 V +5 V Small loads get switched w/ FET instead of HiSide Sw Check out Micrel MIC5018 HiSide MOSFET Driver and Microchip HT0740 Kearfott draws inrush 5A from BUS ( use a ProFET ) ---0--- 12 Jan 2017 office MTG w/ HRH EACH comms port gets its own individual isolation; separate grounds EXAR SP330E TSSOP24 ADuM 6400 series isolator / DC-DC ---0--- 23 Jan 16 office w / HRH Parosci will have it's own dedicated 12V dc/dc converter ( 7 - 25VDC, 270 mA max Model 715 pg 11-1 ) ( 6 to 16 VDC, 38 mA max Model 8107 pg 3-1 ) ( 6 to 16 VDC, 32 mA max Series 8000 - worst case ) Separate dc/dc converter 15 to 25 W for instruments ( keep from taking down whole AUV on instrument failure ) ( 14 Feb 17 ... sample from XP Power JCM3024S12 ) ---0--- 11 Apr 17 Test Board Comms Channel draws 14 mA at 3V3 Need to make changes to SD: Delete OptoIsolator, use a jumper to select RS485/RS232 Break line from SP330E pin 14 to GND, use a jumper to select Half/Full RS485 ---0--- 24 Apr 17 Consider XLP PIC running on Coin Cell Batt Monitors reed sw for start-up / shut-down 3 ea ADCs: 24 V batt, 9 V batt, Coin Cell 1 ea ( at least ) GPIO to enable system DC/DC converters I2c isolated channel for comms with TS4100 CPU Possibly PIC16LF1503 / 1823 Development board DM163046-ND Microchip XLP battery life estimator software Run mode 10 min Sleep mode 24 hours Batt life > 3 years ---0--- 4 MAY 17 Major subsystems: Power Isolated 5V 5W CPU 5V 10W DG14 AHRS Freewave 12V 5W Parosci 12V 30W Instruments 10V 30W Novatech SBD Warrior Backup Batteries 3V CR2032 Start circuit 9V C Cells Novatech SBD Warrior 24V C Cells Acomms Drop Wt Comms 12 serial Channels Acomms Ethernet CPU Start Circuit Super Cap Drop Weight