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Sam -III Construction Manual

3-axis geomagnetometer, simple aurora monitor
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SIMPLE AURORA MONITOR
~SAM-III~
3-Axis Geomagnetometer
CONSTRUCTION MANUAL
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  • Page 1 SIMPLE AURORA MONITOR ~SAM-III~ 3-Axis Geomagnetometer CONSTRUCTION MANUAL Revision history on last page...

  • Page 2: Table Of Contents

    SAM Display and Keyboard Reference Information XIV. Install the Controller, Keyboard and LCD in the Enclosure Magnetometer Sensor Hookup XVI. Magnetometer Sensor Installation XVII. Temperature Sensor XVIII. Circuit Description Appendix Using SysInternals PortMon Document History File: SAM-III Magnetometer Construction.doc, Page 0...

  • Page 3: Description

    (software). It is based on the 2-axis SAM. A schematic is provided at the end of this document. The basis for the SAM-III is a fluxgate magnetometer sensor manufactured by Speake & Co Llanfapley. The sensor signals are processed on the signal processor module, which uses a Microchip PIC16F877 microprocessor.
  • Page 4 Software Setup Guide. Building the SAM-III If you build the SAM-III yourself: Before you start, you should first read through all manual sections and then follow them in order during construction. This will greatly reduce the chances of error. If you choose to build the SAM-III without following this manual, you do so at your own peril and greatly increase your chances of failure.

  • Page 5: General Building Tips

     You will need a digital or analog multimeter to properly assemble and test this kit. it must be able to read resistance up to 500k ohms and voltage up to about 20 Vdc.  Before starting assembly, perform an inventory of all components – see the file SAM Kit Parts List.xls on the CD ...

  • Page 6: Separate The Controller Pcb And Keyboard Pcb

    It may be helpful to sandwich the PCB between two pieces of soft wood and clamp in a vise while cutting; do not clamp the PCB directly in the vise jaws. See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 4...

  • Page 7: Install Keyboard Components

    Double-check all components for location and check polarity sensitive components (LED and PCB header)  Double-check all soldering When the keyboard PCB is finished it should look like the illustration below. Set the keyboard PCB aside. See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 5...
  • Page 8 SAM-III Construction Manual See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 6...

  • Page 9: Install The Power Supply Components

    18-pin x 0.3 in. DIL (not supplied) ►  IC socket 6-pin x 0.3 in. DIL (not supplied) ► ► Indicates pay attention to polarity or direction See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 7...
  • Page 10 + polarity  Solder the pluggable terminal blocks. The holes are very slightly oversized, so take care to align the terminal blocks parallel to the PCB edge See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 8...
  • Page 11 Note: The + terminal of the battery has two pins on the edge and the – terminal has one pin. Your SAM-III Kit includes one of two battery types, with slightly different spacing between the + and – terminals. The PCB may be equipped with one or two holes for the –...
  • Page 12 SAM-III Construction Manual See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 10...

  • Page 13: Test The Power Supply

    If you supply your own ac adapter its output must be rated at least 9 Vdc, 200 mA under load. DO NOT attempt to power the SAM-III with an under-rated ac adapter. DO NOT use an ac adapter with an output higher than approximately 17 Vdc when under load.
  • Page 14 If the voltages or load current are not within the specified ranges, check for shorts, solder bridges and orientation of polarity sensitive components (electrolytic capacitors, diodes, and voltage regulator ICs). Do not continue until you have fixed the problem. See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 12...

  • Page 15: Install The Logic Circuits

    Solder the IC socket in position with the small notch at the end near U6 See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 13...
  • Page 16 The wafer or paper raises the crystal a little above the PCB and prevents it from touching the traces. Solder crystal Q1. DO NOT overheat the crystal as it could be damaged All controller PCB soldering is done. See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 14...
  • Page 17 The controller board should now look similar to the pictures below (some components may look slightly different). Set the controller PCB aside but do not set it on a conductive surface. See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 15...
  • Page 18 SAM-III Construction Manual See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 16...

  • Page 19: Install The Display Components

    LCD module, and the row of pins closest to the polarizing slot will rest against the board edge. See illustration below  Carefully solder the 16 pins All printed circuit boards are now done. See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 17...

  • Page 20: Install The Ribbon Cables

    After assembly, trim the cable with a razor blade or hobby knife  After the connectors are installed, fold the cable over the top of the connector and snap the strain relief into place See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 18...
  • Page 21  Lay the boards as shown in the illustration below with the 34-pin and 10-pin headers facing up  Carefully insert the connectors in the sockets. They will fit only one way  Turn the three boards over See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 19...

  • Page 22: Wire The Eia-232 Serial Port Cable

    This section describes several serial port configurations. The first one, described immediately below, wires the SAM serial port as Data Terminal Equipment (DTE) with a DB-9M connector. This requires a null modem cable (supplied with kit) in which pins 2 and 3 are reversed on one of the connectors. One of the other configurations wires the SAM serial port as Data Communications Equipment (DCE) so that it can be connected to a PC with a straight-through cable and not a null modem cable.
  • Page 23 (or USB/EIA-232 adapter) without a null modem cable. Instead, a straight-through cable may be used that has a DB-9M plug at one end (SAM-III) and DB-9F plug at the other end (PC). Even though a null modem cable is supplied with the SAM-III Kit, some users may prefer using this more common arrangement.
  • Page 24 SAM-III Construction Manual See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 22...

  • Page 25: Testing And Adjusting

    The operating system firmware (SAM3_ENG.HEX) and sensors will be installed and tested later.  Connect the LCD module, keyboard, power connector and EIA-232 serial port connector to the SAM- III PCB as shown below. Do not connect anything to the Aux Controls plug (X1) or Sensors plug (X2) at this time.
  • Page 26 This is especially important if you are using Windows 7. Check for the latest drivers now. Initial Power Up Connect the ac power adapter to the SAM-III controller board and plug the ac adapter into an ac outlet receptacle. The LCD probably will not show anything at this time. With no sensor connected, the current draw will be around 50 mA with the LCD backlight on and around 30 mA with it off.
  • Page 27 If you have problems, measure the Vcc pins on the ICs. You will have to refer to the schematic to determine the pins. Also, measure the current drawn by the SAM-III. It should be nominal 50 mA. A current draw significantly higher or lower indicates a problem with a component or the soldering. Use normal troubleshooting procedures to clear the problem before going to the next test.
  • Page 28 Setup HyperTerminal Start the HyperTerminal program (Start – All Programs – Accessories – Communications) and create a new connection. If you had a connection setup for a SAM-II, you may skip the setup and just open the connection. Select File – New Connection.
  • Page 29 Choose the appropriate COM Port from the dropdown list. If you are using a USB-serial adapter, this is the COM Port used by the adapter. Plug the adapter into a USB port, but DO NOT connect it to the SAM- III serial port.
  • Page 30 Reset pushbutton on the main PCB. After the processor has booted, press F1, F2, F3 and F4 in that order as in the Test the Keyboard section above. A moment after pressing F4, the SAM-III starts transmitting the test message and it should appear in the HyperTerminal window.
  • Page 31  pin 5 (negative multimeter lead) to pin 3 (positive multimeter lead) In both cases, the voltage should be in the range –6V to –12V. If not, remove power from the SAM-III and try swapping pins 2 and 3 on the DB-9M connector or the 3-pin header connector. A good software tool for troubleshooting serial ports is PortMon for Windows.
  • Page 32 Use the F2 or F3 function keys to scroll the year field. When set to the correct year, press F1. The screen to set the hour appears 25.07.09 00:31:10 Set time: hour F1=OK F2=+ F3=- See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 30...
  • Page 33 (the real time clock IC is battery powered by G1). However, if you ever remove the JP2 header shorting block with no power on the SAM-III, the clock will have to be reset. This can be done when the SAM is in operation as described in the Software Setup Guide.
  • Page 34 Digital input: Test aborted If the test is aborted, the SAM-III automatically will go to the next test. To proceed with the test, refer to the X1 terminal block pinout shown above. Connect the + lead from an isolated 12 Vdc power supply to pin 1 of X1 and the – lead to Pin 2. Note: 12 V dc is available between pin 7 (+) and pin 8 (–) of X1.
  • Page 35 SAM-III Construction Manual The output can be calibrated to provide a range of 0 to +5 V or –2.5 to +2.5 V. The SAM-III analog output is proportional to K-index, so it is recommended that it be calibrated for a range of 0 to +5 V. If you do not plan to use the analog output, this step can be skipped.
  • Page 36 All tests are now done! The above tests and adjustment can be repeated by pressing the reset button on the SAM-III controller PCB. You have to cycle through the entire set of tests but you can skip a particular test or adjustment by pressing F1.
  • Page 37 If you just finished construction of the SAM-III PCBs, you normally would press F1 to load the default parameters. On the other hand, you would press F2 if you had been using the SAM-III for some time and wanted to readjust the analog output or retest a function but wanted to retain the parameter settings from previous use.

  • Page 38: Load The Microprocessor Operating System Firmware

    Note that either IB3_ENG.HEX or SAM3_ENG.EXE can be loaded onto the microprocessor but not both at the same time. In general, IB3_ENG.HEX is loaded when it is necessary to test and adjust the SAM-III, and SAM3_ENG.EXE is loaded when the SAM-III is to be placed in service.
  • Page 39 The application program (SAM_VIEW) will automatically detect whether or not temperature data is in the SAM-III data stream. If you load SAM3_ENG.HEX and later decide to use the temperature sensor, you can easily replace it with SAM3T_ENG.HEX at that time.
  • Page 40 If the sequence does not complete properly, see Troubleshooting PIC downloader below. After the SAM-III has rebooted, press the RESET (F3) button on the SAM-III keyboard. The SAM-III should reset and the LCD should look like this (line 4 initially will be blank but will appear after a moment) ...
  • Page 41 Oscilloscope: PC → SAM-III, measured at Pin 2 of JP1 while waiting to press RESET to download IB3_ENG.HEX from PIC downloader: Image F0000TEK See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 39...
  • Page 42 SAM-III → PC, measured at Pin 3 of JP1 while wai[ng to press RESET to download IB3_ENG.HEX: Approximately –7 Vdc PC → SAM-III, measured at Pin 2 of JP1 after pressing RESET and while receiving IB3_ENG.HEX from PIC downloader: Image F0001TEK PC →...
  • Page 43 SAM-III → PC, measured at Pin 3 of JP1 while sending "RS232" text to HyperTerminal: Image F0005TEK PC → SAM-III, measured at Pin 2 of JP1 while sending "RS232" text to HyperTerminal: Approximately –9 PC → SAM-III, measured at Pin 2 of JP1 while waiting to press RESET to download SAM3_ENG.HEX from PIC downloader: Image F0006TEK...
  • Page 44 SAM-III Construction Manual SAM-III → PC, measured at Pin 3 of JP1 while wai[ng to press RESET to download SAM3_ENG.HEX: Approximately –7 Vdc PC → SAM-III, measured at Pin 2 of JP1 while receiving SAM3_ENG.HEX in progress from PIC downloader: Image F0007TEK SAM-III →...
  • Page 45 SAM-III Construction Manual See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 43...

  • Page 46: Sam Display And Keyboard Reference Information

    SAM-III Construction Manual XIII. SAM-III Display and Keyboard Reference Information SAM Display: The SAM-III display is a 4x20 (4 lines x 20 characters per line) LCD with the following layout: Line Example  X:____________  Y:____________  Z:____________ K:4(5) D:61nT 21:42 Line 1, 2 &...
  • Page 47 Geomagnetism Tutorial available from the following web address: http://www.reeve.com/Documents/SAM/GeomagnetismTutorial.pdf The K-index triggers can be changed in the SAM-III processor for standalone mode by using the SAM_INI version 2.0 program. The charting program, SAM_VIEW, also has its own triggers for computing the K- index so the values have to be set twice - in the microprocessor EEPROM for standalone operation using SAM3_INI and again in SAM_VIEW for logging operation with a PC.
  • Page 48 SAM-III Construction Manual See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 46...

  • Page 49: Install The Controller, Keyboard And Lcd In The Enclosure

    LCD and keyboard, but additional spacers are required (spacers are supplied with the optional enclosure). When viewing the enclosure from the front, the open See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 47...
  • Page 50 Controller PCB, viewed from top (component side); NOT full size. The controller PCB is mounted to the base section (see next drawing) See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 48...
  • Page 51 SAM-III Construction Manual See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 49...
  • Page 52 These line up with the two outer holes in the keyboard PCB and provide sufficient support for most applications. If additional support is needed, use a spacer (not supplied) at the middle hole in the keyboard. See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 50...
  • Page 53 Ø 3.5 mm Ø 8 – 12 mm Recessed area on top of enclosure Dimensions shown are nominal and should be verified before cutting the holes 87.00 See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 51...
  • Page 54 A keyboard label image is provided on the supplied CD. Print it and trim the holes with a sharp hobby knife. Not full size. Keyboard label for use with the SAM See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 52...

  • Page 55: Magnetometer Sensor Hookup

    SAM-III Description The sensors are manufactured for the SAM-III by Speake & Co Llanfapley. Up to three sensors can be used (see picture below). The sensors have four pins and the label on the sensor indicates pin designations. Note that the sensors are potted into a plastic tube. Some shrinkage may take place during the curing operation or from temperature cycling, creating what appears to be an air bubble under the clear plastic tube.
  • Page 56 One, two or three sensors can be connected to the SAM-III. The schematic diagram below shows three sensors. This drawing assumes the 78L05 voltage regulators U1, U3 and U4 are installed on the controller PCB and the sensors are fed with 5 V power from the controller.
  • Page 57 SAM-III Construction Manual Note: Crosstalk interference is likely when two or more sensors use the same cable. This is discussed later under Mutual Interference. See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 55...
  • Page 58 4. Refer to SAM-III Construction Manual for bonding/grounding information. Each site is different! 5. Other types of cable may be suitable or required. See SAM-III Construction Manual 6. Observe polarity of tantalum capacitors...
  • Page 59 SAM-III Construction Manual Sensor power Each sensor is powered by a dedicated +5 V voltage regulator on the SAM-III controller (78L05, U1, U3 and U4). Each sensor draws around 15 mA. In some applications, it may be desirable to move the sensor voltage regulator from the SAM-III controller PCB to the sensor location to improve voltage regulation at the sensor.
  • Page 60 SAM-III Construction Manual Sensor cable The cable between the SAM-III controller and the sensors is user supplied. An installation with three magnetometer sensors and a temperature sensor will require a total of 10 conductors (10 conductors if no temperature sensor). It is possible to share the ground conductor in installations if the cable is not too long (say less than 10 m).
  • Page 61 The following information was provided by Darrel Emerson, who performed some undocumented testing on the SAM-III sensors. If two sensors are parallel and too close, they tend to pull each other onto the same frequency. In the parallel configuration, it is recommended that the sensors be separated by at least 150 mm (6 in.) to minimize this effect.
  • Page 62 5. Use the radio transmitter PTT to activate the input voltage detector. When +12 V dc is applied to pin 1 with respect to pin 2 of terminal block X1 the SAM stops measuring the sensor output. In this way, the SAM-III will ignore the interference during transmission. When the PTT is released,...
  • Page 63 If a frequency counter is connected to the output of each sensor, the counter should show a frequency close to the frequency on the SAM-III display when the processor module is in Calibration mode (the tolerance is not specified). Note: The sensor output is a logic level squarewave, and it is possible the frequency counter will measure an odd harmonic.
  • Page 64 SAM-III Construction Manual The SAM-III sensors are very sensitive and will give erratic readings when placed in an uncontrolled or magnetically noisy environment. It is a common mistake of first-time users to misinterpret the erratic readings as a malfunctioning sensor or SAM-III controller problem. Any tiny movement of the sensor or movement of metallic objects in the vicinity of the sensor will affect its output.

  • Page 65: Magnetometer Sensor Installation

    Magnetic field components It is first necessary to decide what component or components of the magnetic field are to be measured. The SAM-III supports one, two or three sensors, so it may be setup to measure the following combinations: 1-sensor installation,...
  • Page 66 Refer to the Geomagnetism Tutorial for additional information. The standard for the SAM Magnetometer Network project is geographic coordinates, X, Y and Z, with reference to true north. This means the N-S sensor is installed with the cylinder axis horizontal and pointed toward true north.
  • Page 67 Place the sensors in a magnetically quiet location where they will experience as little local magnetic disturbance as possible, usually in an open field or yard away from any buildings and automobile traffic. See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 65...
  • Page 68 24 hours. Field Use The SAM-III sensors have proven to be very robust in the field and have survived incorrect signal and power connections and shock from being dropped. However, they should never be routinely treated that way.
  • Page 69 SAM-III Construction Manual Buried Sensor Fixture – Single-sensor installation, Typical See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 67...
  • Page 70 SAM-III Construction Manual Buried Sensor Fixture – Three-sensor installation, Typical (all components in USA trade sizes) See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 68...

  • Page 71: Temperature Sensor

    The temperature is not displayed on the LCD because there is no room for it. The temperature data is included in the SAM-III data stream only if a digital thermometer is detected. If a digital thermometer is not detected, the data stream will not include temperature data.
  • Page 72 SAM-III Construction Manual Temperature sensor test: After installing the digital thermometer, turn on power to the SAM-III and then run SAM_VIEW. Go to the directory or folder where SAM_VIEW stores the data (specified in Edit – Setup – Logging – Data Directory).

  • Page 73: Circuit Description

    (10 or 50 parts per million frequency precision, depending on part number) and keeps track of date and time. The SAM-III includes a battery, G1, and voltage steering diodes, D3 and D4, for the real-time clock. Terminal block JP2 allows the battery to be disconnected. A pull-down resistor, R11, is used for U8 chip select.
  • Page 74 RC7 programmable input. This input channel normally is used only during setup of the SAM-III. Capacitors, C15, C16, C17 and C18, are charge pump capacitors necessary for the operation of the EIA-232 transceiver, whose main function is to convert the microprocessor TTL/CMOS voltage levels (0 and 5 V) to EIA-232 voltage levels (typically ±...
  • Page 75 A four-button keyboard, consisting of S2, S3, S4 and S5, associated pull-down resistors R3, R4, R5, and R6, and isolating diode, D2, are used to control the SAM-III. The keyboard PCB also has an indicator LED, D5. Resistor, R7, provides current limiting for the LED.
  • Page 76 SAM-III Construction Manual Main Controller Schematic Diagram See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 74...
  • Page 77 SAM-III Construction Manual Keyboard Schematic Diagram See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 75...
  • Page 78 SAM-III Construction Manual PCB Component Layout See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 76...

  • Page 79: Appendix Using Sysinternals Portmon

    To troubleshoot, compare your PortMon logs to those shown. See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 77...
  • Page 80 20:20:07 PM PIC_downloader. IOCTL_SERIAL_CLR_RTS Serial2 SUCCESS 2050 20:20:07 PM PIC_downloader. IOCTL_SERIAL_CLR_DTR Serial2 SUCCESS 2051 20:20:07 PM PIC_downloader. IRP_MJ_CLEANUP Serial2 SUCCESS 2052 20:20:07 PM PIC_downloader. IRP_MJ_CLOSE Serial2 SUCCESS See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 78...
  • Page 81 20:17:06 PM PIC_downloader. IOCTL_SERIAL_CLR_RTS Serial2 SUCCESS 3236 20:17:06 PM PIC_downloader. IOCTL_SERIAL_CLR_DTR Serial2 SUCCESS 3237 20:17:06 PM PIC_downloader. IRP_MJ_CLEANUP Serial2 SUCCESS 3238 20:17:06 PM PIC_downloader. IRP_MJ_CLOSE Serial2 SUCCESS See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 79...

  • Page 82: Document History

    Portions of the manual were translated from German. Please let us know if you find errors – send an email to SAMinfo@reeve.com with “SAM Kit” in the subject line (or else your email may be caught by our spam filters).

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