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Copyright © 2014 Grid Insight. All rights reserved.
Grid Insight is a trademark of Gregory C. Hancock d/b/a Grid Insight and has been filed for registration
with the US Patent and Trademark office.
Itron and ERT are trademarks of Itron Inc. Badger and ORION are trademarks of Badger Metering, Inc.
Bluetooth is a trademark of Bluetooth SIG, Inc. Use of all third-party trademarks herein is for nominative
purposes only and should not be interpreted as endorsement of Grid Insight or its products by
trademark owners.
Reproduction, transfer, distribution, or storage of part or all of the contents of this document in any
form without the prior written permission of Grid Insight prohibited.
Grid Insight operates a policy of ongoing development. Grid Insight reserves the right to make changes
and improvements to any of the products described in this document without prior notice.
TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, UNDER NO CIRCUMSTANCES SHALL GRID
INSIGHT BE RESPONSIBLE FOR ACCURACY OF RECEIVED DATA, LOSS OF INCOME, OR ANY SPECIAL,
INCIDENTAL, CONSEQUENTIAL, OR INDIRECT DAMAGES HOWSOEVER CAUSED.
THE CONTENTS OF THIS DOCUMENT ARE PROVIDED “AS AS”. EXCEPT AS REQUIRED BY APPLICABLE
LAW, NO WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE
MADE IN RELATION TO THE ACCURACY, RELIABILITY, OR CONTENTS OF THIS DOUCMENT. GRID INSIGHT
RESERVES THE RIGHT TO REVISE THIS DOCUMENT OR WITHDRAW IT AT ANY TIME WITHOUT PRIOR
NOTICE.
Reverse engineering of any firmware in the Grid Insight device is prohibited to the extent permitted by
applicable law.
This device may contain technology or firmware subject to export laws and regulations from the US and
other countries. Diversion contrary to law is prohibited.
Document Version 20140827 DRAFT
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Safety and Performance Guidelines
When using the Grid Insight device, you must follow a few simple guidelines. Not following them may be
dangerous or illegal. Please read the remainder of this user guide carefully for additional information.
Device contains a lithium-ion battery than may catch fire if
damaged.
Device is susceptible to interference, especially in the range of
900 – 930 MHz, which could affect performance.
Device contains sensitive electronics and a protruding on/off
toggle switch. Don’t drop it.
Take the device to an e-Stewards or Responsible Recycling
Standard (R2) certified electronics recycler for proper disposal.
Device is not water resistant. Keep it dry.
Eye poking hazard. Keep away from children.
Li-Ion Battery Warnings
The Grid Insight device contains a rechargeable 4.5 Wh lithium-ion battery. Full specifications and
certifications for the battery are available from Grid Insight upon request.
The internal battery is not user serviceable. For battery replacement, contact Grid Insight.
If at any time you witness the device smoke or get hot, disconnect the device from the charger
immediately and observe it in a safe place for approximately fifteen minutes. A damaged or failed
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battery may leak, and the reaction with air may cause the chemicals to ignite, resulting in fire. Do not
use the device, and contact the manufacturer for further instructions.
Do not expose device or battery to water and do not incinerate or expose battery to temperatures
above 60ºC/140ºF.
Do not attempt to disassemble the battery, pierce the battery with a sharp object, or bend the battery.
A damaged or leaking battery should be handled with extreme care. Personal injury may result from the
mishandling of a damaged or leaking battery.
If leaking fluid gets into a person’s eyes, they should not rub the eye. Rinse the eye well with water and
immediately seek medical care.
Keep battery away from children.
Shipment Restrictions
Due to fire hazard, shipment of lithium-ion batteries is regulated by law in the US and other
jurisdictions. Consult your shipper’s dangerous goods department or an IATA- trained dangerous goods
shipping specialist for more information on how to safely and legally ship the Grid Insight device. For
example, the package may need to be labeled with something like the following:
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DECLARATION OF CONFORMITY
According to FCC Part 15
Responsible Party Name:
Gregory C. Hancock d/b/a Grid Insight
Address:
182 Howard Street, PMB 632
San Francisco, CA 94105
Telephone:
415-449-4757
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:
(1) this device may not cause harmful interference, and (2) this device must accept any interference
received, including interference that may cause undesired operation.
Contains Transmitter Module FCC ID: T9J-RN42.
This device complies with FCC radiation exposure limits set forth for an uncontrolled environment. This
device must not be co-located with any other transmitters.
Use only the supplied charger. Use with other chargers, or connecting to a USB host device, may violate
FCC rules and voids your authority to operate this equipment.
Additional information on FCC Part 15 compliance
This device meets the SAR Test Exclusion Threshold condition for head or body radiation exposure as
specified in FCC KDB 447498 D01 General RF Exposure Guidance v05r02, page 11. Device contains
Bluetooth transmitter module model RN-42 from Microchip Corporation with maximum peak power
output of 0.004 W.
Industry Canada Compliance Statement
CAN ICES-3 (B)/NMB-3(B)
Contains IC: 6514A-RN42.
This Class B digital apparatus complies with Canadian ICES-003.
Cet appareil numérique de la classe B est conforme à la norme NMB-003 du Canada.
System Requirements
This device requires a host device that is compatible with Bluetooth 2.1 and the Bluetooth Serial Port
Profile (SPP). The following platforms have been tested for compatibility:
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Windows 7 Professional running on Lenovo X220 laptop with built-in Bluetooth radio
Windows 7 Professional running on Lenovo ThinkStation E32 desktop with ASUS USB-BT400 Bluetooth
4.0 Dongle.
Google Nexus 4 smart phone running Android 4.4.4 build KTU84P.
Specifications
Battery type
Lithium ion prismatic single cell, 3.7 V nominal
Battery capacity
1200 mAh
Runtime on a full charge
Greater than 16 hours
Stand-by time on a full charge
Greater than 72 hours
Charge voltage and maximum current
5 V @ 220 mA
Receive range for Badger ORION fixed-frequency
signals
Approximately 100 feet line-of-sight
Receive range for Itron 60W and 100W FHSS SCM
signals
Approximately 10 to 40 feet line-of-sight
(depending on antenna angle), decreasing in the
presence of obstructions or interference
Dimensions
4” H x 2 7/8” W x 1 1/4” D
Weight
3.8 oz
Enclosure material
UL-rated molded ABS plastic
Indicator LEDs
The NB-407 uses three LEDs to communicate important status information as follows:
GREEN
RED
YELLOW
Bluetooth connection status
Serial data activity
Charging status
Flashing means ready to
connect. Goes solid on when
connected. Goes off when
battery is fully depleted or unit is
in forced SLEEP mode.
Flashes to indicate serial data
transfer via Bluetooth SPP
On when charging. Off when
either disconnected from
charger or charge is complete.
Rapid flashing indicates charge
error.
Receiver Operation
The device contains two receiver chains, both tuned to the 902 – 928 MHz ISM band in which many
utility meter endpoints operate. The first of these is a highly-configurable, high-sensitivity, narrow-band
receiver suitable for reception of fixed-channel signals. The second is a low-sensitivity, wideband
receiver suitable for reception of frequency-hopping signals with unknown or unsynchronized hopping
pattern. Using these two receivers together, the device is able to receive Standard Consumption
Message (SCM) automated meter reading (AMR) signals from Itron 60W and 100W water meter
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endpoints as well as ORION AMR signals from Badger ORION universal pit transmitters and integrated
register-transmitters.
Itron SCM Reception
The NB-407 was designed to be a general purpose data receiver capable of receiving and decoding
digital utility metering signals from a variety of transmitters. In the present firmware version, the NB-
407 works with transmitters that employ the Standard Consumption Message (SCM) radio protocol and
packet syntax pioneered by Itron’s ERT products. Some products by Schlumberger and at least one by
Hunt Technologies also use this protocol. We will refer to these transmitters collectively as “ERT-
compatible transmitters”.
The NB-407 receiver hides the detail of the underlying proprietary radio protocol, allowing end-user
applications to simply connect to the receiver and utilize the received and decoded meter readings. For
the purposes of understanding receiver performance, however, we must cover a few basic elements of
the radio technology and data protocol used by ERT-compatible transmitters.
The SCM protocol is proprietary to Itron, so public documentation is not readily available. The protocol
is not encrypted and is transmitted over unlicensed airwaves in the 900 MHz industrial, scientific, and
medical (ISM) band.
ERT-compatible transmitters employ a type of frequency-hopping spread spectrum transmission
technique. This helps to avoid interference in mobile and fixed-network applications.
ERT-compatible transmitters have come in a variety of types since they first came to market around
1990. The NB-407 is a general-purpose receiver than can receive signals from any specific transmitter
model. (Note that ERT-compatible transmitters always include an “ERT type” field in their transmissions;
the ERT type varies between electricity, water, and gas, among other things.) An ERT-compatible
transmitter may transmit from 916 to 918 MHz, or from 911 to 915 MHz, or from 916.5 to 917.2 MHz (or
some other range), utilizing a random non-channelized frequency-hopping pattern. Some transmitters
occasionally change their hopping range seemingly arbitrarily. Other compatible transmitter models
transmit in adjacent, discrete channels utilizing 10 MHz or so of the 26 MHz available within the ISM
band. Discrete channelization is required by FCC Part 15.247. Still other models use several chunks of
non-adjacent channels.
The NB-407 handles all this variation listening to a wide frequency range all at once rather than hopping
around. This allows it to receive almost all of the transmissions from the target transmitter, despite the
fact that they are being transmitted on a variety of channels. There is a trade-off for this, however:
physical range is limited.
The receiver is equipped with a wideband radio for receiving frequency-hopping Itron SCM signals. This
is a low-power means of detecting these signals suitable for a light-weight, portable receiver, but it only
works at close range and in the absence of strong interference on nearby frequencies. Under ideal
conditions with no interference, the wideband SCM receiver has a range of over 25 feet and should work
fine if you are wearing it on your belt and standing near the target endpoint. SCM signals are in the 900
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MHz band, so the wideband receiver is susceptible to interference from other 900 MHz devices such as
older cordless phones and baby monitoring systems. The presence of interference may further limit the
receiver's range, but you can always overcome the interference by moving the receiver closer to the
metering endpoint. In the worst case, you may have to remove the receiver from your belt and hold it
within a few feet of the endpoint – perhaps removing obstructions (like the pit lid).
Note that the wideband SCM receiver uses an internal antenna located within the device as shown in
Figure X. <insert figure> This antenna as on the bottom of the device as it is usually worn, which
improves reception toward the ground where many water meters are located. However, in some cases
you may get better results by holding the receiver upside down. Moving it away from your body and
aiming the label face of the receiver toward the endpoint will also improve reception. Radio waves are
tricky, so keep an eye on the signal strength readings and experiment a little to find what works best for
you.
On average, you should expect to get an SCM reading from any specific Itron 60W transmitter about
every 7 or 8 seconds as long as the device is in range.
Badger ORION Reception
The receiver uses a narrowband radio for receiving non-hopping Badger ORION signals. (The standard
device firmware may also receive signals from Badger ORION frequency-hopping spread spectrum
(FHSS) endpoints, but this is not supported.)
The narrowband receiver uses an internal antenna that is oriented as shown in Figure Y. <insert figure>
Receive range is greater than 100 feet in most environments. You will receive Badger ORION readings
from any specific transmitter about every 4 or 5 seconds.
Interface Specification
The device operates as a full-duplex serial device over Bluetooth. Interaction with it is similar to working
with a serial data modem, except the device employs a slightly different command language from the
“AT” commands used by a typical modem. Moreover, the receiver can accept commands at any time; it
does not need to be switched into a separate command mode with the “+++” command as is necessary
with a telecommunications modem.
Because the device operates as a virtual serial device over Bluetooth by implementing the Bluetooth
Serial Port Profile (SPP) standard, it does not have a fixed baud rate like a standard RS-232 device. For
that reason, it will work with serial terminal software configured for any baud rate.
To send a command to the device, simply transmit the command on the serial interface followed by a
carriage return and linefeed (or simply a linefeed). If a parameter is required, append it to the
command, separated from the command by a space character. Multiple parameters should be delimited
by the space character. For example, here is a typical command/response exchange (with control
characters shown for clarity):
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Sent:
VOLT<CR><LF>
Received:
$VOLTS,4.179*5B<CR><LF>
Every valid AMR data packet received by the device is output on the serial interface in the form of a one-
line data sentence. Details appear later in this document. Here is an example indicating reception of an
instantaneous reading of 172185 units (may be gallons, m3, or ft3), for an ERT Type 13 water meter
endpoint with ERT serial number 27249660:
$UMSCM,27249660,172185,13,4,102*6E
Every sentence conforms to the NMEA 0183 sentence format, as described here:
NMEA 0183 Application Layer Protocol Rules
------------------------------------------
Copied from Wikipedia page “NMEA 0183” (http://en.wikipedia.org/wiki/NMEA_0183) on 2011-03-13.
* Each message's starting character is a dollar sign.
* The next five characters identify the talker (two characters) and the type of message
(three characters).
* All data fields that follow are comma-delimited.
* Where data is unavailable, the corresponding field contains NUL bytes (e.g., in "123,,456",
the second field's data is unavailable).
* The first character that immediately follows the last data field character is an asterisk,
but it is only included if a checksum is supplied.
* The asterisk is immediately followed by a two-digit checksum representing a hexadecimal
number. The checksum is the exclusive OR of all characters between the $ and *. According to the
official specification, the checksum is optional for most data sentences, but is compulsory for
RMA, RMB, and RMC (among others).
* <CR><LF> ends the message.
As an example, a waypoint arrival alarm has the form:
$GPAAM,A,A,0.10,N,WPTNME*32
where:
GP Talker ID (GP for a GPS unit, GL for a GLONASS)
AAM Arrival alarm
A Arrival circle entered
A Perpendicular passed
0.10 Circle radius
N Nautical miles
WPTNME Waypoint name
*32 Checksum data
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In addition to the data sentences representing received data, every command also triggers the receiver
to output a data sentence. Command response sentences are therefore interspersed with receiver data
sentences in the serial data stream. Each sentence type, whether command response or received data,
can be distinguished from by the five-digit sentence type prefix.
Two exceptions to this are that some commands return a simple OK:
OK<cr><lf>
And critical error messages may be reported in plain text, such as:
SCM BUFFER OVERFLOW<cr><lf>
Commands
Command
Description
VOLT
Read the instantaneous li-ion battery voltage.
BOMOFF
Turns off Badger ORION read capability.
BOMON
Turns on Badger ORION read capability (default).
SCMOFF
Turns off Itron SCM read capability.
SCMON
Turns on Itron SCM read capability (default).
RESET
Reset the device – same as turning power switch off/on.
TEST
Goes into EMI test mode. Bluetooth module is disabled but all
other subsystems remain operational. (Not recoverable
without hard reset.)
SLEEP
Shuts down as much of the device as is possible, minimizing
battery consumption. (Not recoverable without hard reset.)
Data Message Formats
Every received data sentence represents one data packet received over the air. Before the receiver
outputs the sentence, it validates the data packet against its internal checksum to ensure the data is
complete and has not been corrupted during transmission.
The receiver then decodes the data packet and assembles the data elements into a sentence following
NMEA 0183 syntax before writing it out on the serial interface.
UMBOM
Each received Badger ORION message causes the receiver to output a single UMBOM line like so:
$UMBOM,70462785,999999,137,0,140*49
The fields are:
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1. UMBOM
2. Endpoint serial number (ID)
3. Consumption register
4. Flags 1 (8-bit decimal bitfield)
5. Flags 2 (8-bit decimal bitfield)
6. Signal strength (dB scale)
Following everything is *XX where XX is an eight-bit hex value representing the XOR checksum of the
ASCII sentence after the “$”.
UMSCM
Each received Itron SCM message causes the receiver to output a single UMSCM line like so:
$UMSCM,19016066,1,13,0,125*53
For UMSCM (Utility Meter Standard Consumption Message), the format is about the same:
1. UMSCM
2. Endpoint serial number (ID)
3. Consumption register
4. ERT type code (13 for 60W)
5. Tamper Flags (8-bit decimal bitfield)
6. Signal strength (log scale – not dB calibrated)
VOLTS
In response to the VOLT command, the receiver outputs a single line:
$VOLTS,4.179*5B
The fields are
1. VOLTS
2. Battery voltage to thousandths precision, though the value is only accurate out to hundredths.
Connecting to the Receiver
First off, you will need to pair the Bluetooth device with your computer. Below are instructions for doing
this in Windows 7. For other operating systems, consult your device’s documentation.
Pairing on Windows 7
In Windows 7, make sure you have a Bluetooth icon in your taskbar:
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Figure 1. Windows 7 taskbar showing Bluetooth icon (circled in red)
Switch on your receiver. The green LNK (link) LED will flash to indicate that the receiver is ready to
accept a Bluetooth connection. Right click the Bluetooth icon, then select Add a Device.
Your device ID should appear in the window:
Figure 2. Windows 7 Bluetooth Add a device dialog
Select the device, then click Next.
If you are prompted to verify a pairing code, simply approve it and click Next (having no physical display,
the receiver cannot show you the code for verification):
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Figure 3. Windows 7 Bluetooth pairing dialog
NOTE: You may be asked to enter the pairing code provided by the device manufacturer. If so, enter
1234, the pairing code printed on the device.
The Windows Bluetooth manager will information you that the device is installed:
Figure 4. Success adding a Bluetooth device
It may take another couple of minutes for Windows to configure the new virtual serial ports associated
with the receiver. Wait until you see a Your device is ready to use message balloon appear in your
taskbar.
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At this point, the LNK LED will remain flashing even though the receiver is associated with your
computer. This is normal.
Using a Serial Terminal
TeraTerm is a free serial terminal application that runs on Windows and works well with the Grid Insight
receiver. You can obtain a copy from http://ttssh2.sourceforge.jp/.
Launch TeraTerm. In the New connection dialog, you'll see two new virtual COM ports. The first of these
is used to communication with the device's serial interface. Select it, then click OK.
Figure 5. TeraTerm new connection dialog
Connection status will update in the title bar of the new TeraTerm window. It will show “connecting...”
for a few seconds, then will change to reflect the baud rate, even though the baud rate is irrelevant on a
Bluetooth COM port.
The receiver's LNK LED will turn solid green to indicate an active serial connection. The receiver will
reset, count out dots for eight seconds (or press 'b' to boot immediately), display a boot message, and
then begin listening for both SCM and Badger ORION data traffic.
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Figure 6. Boot message and received data
Charging and Battery Monitoring
Charging can take up to 8 hours. Charging should only be done with the supplied micro-USB charging
adapter.
The receiver supports the VOLT command to query the current rechargeable lithium-ion battery voltage.
The voltage reading will range from a maximum of approximately 4.2 volts at full charge to as low as 3.0
volts at total discharge1. Given its non-linear discharge voltage curve, correlating voltage to remaining
percent of charge is tricky. See Figure 7 to get a general sense for how battery voltage compares to
percent of discharge. When the battery reaches 3.5 Volts, the user should be told to switch off the
device and stop using it until it can be recharged. When it reaches 3.2 V, the application software can
issue the SLEEP command to shut down the device and avoid depleting the battery to the point where
1 Reported values vary by about 2% from device to device due to component tolerances.
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the safety shutoff activates at 3.0 V. The receiver's discharge rate while fully active is about 0.05C (70
mA / 1200 mAh), so the discharge curve is especially flat from about 50% discharge to 95% discharge.
Figure 7. Lithium ion discharge plot. (Courtesy of Lady Ada at adafruit.com)
The receiver supports the SLEEP command which turns off as much of the circuitry as possible to reduce
battery depletion. However, SLEEP mode cannot be canceled by software – the user must physically
switch off and on the power switch. In SLEEP mode, current draw drops to under 10 mA.
Firmware Update
The device is equipped with a firmware bootloader that allows the device's application firmware to be
updated by the end user. The installed application firmware version number is included in the boot
message output to the Bluetooth serial interface:
...................
*****************************************************
Grid Insight "Naselle B" Firmware v. 0.0.7 (BETA)
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Compiled on Aug 18 2014 at 10:34:51.
Copyright 2014 Gregory C. Hancock.
Chip ID: 24353B0252EEEB41
*****************************************************
New firmware can be uploaded to the receiver using the Xmodem over the Bluetooth serial interface.
Connect a Bluetooth-enabled PC and Xmodem-enabled serial terminal software such as TeraTerm to the
device and follow the steps below to easily upgrade or downgrade the application firmware.
To update the firmware, press the “!” key during the eight seconds before the boot message appears. (If
you miss the opportunity, simply run the RESET command within the application firmware to reboot.)
After pressing ‘!’, you will see the bootloader prompt:
...........
Energy Micro EFM32G Bootloader 1.6.5
Grid Insight "Naselle B" mod v. 1.0.1
ChipID: 24353B0252EEEB41
The bootloader is intentionally very simple in order to fit it in a small memory space. The following
commands are supported:
Upload
The 'u' command will upload an application. Use your terminal software to transfer the application
binary to the chip. After completing the upload you might wish to verify the correctness by calculating
the CRC-16 on the uploaded binary. This can be achieved by the 'verify application checksum' command
(See Section 3.1 (p. 7) ). To start the application from the bootloader use the 'boot' command ('b' - see
Section 4.1 (p. 8) ).
The 'd' command will start a destructive upload. Use your terminal software to transfer the binary to the
chip. Destructive upload differs from regular uploads in that it overwrites the bootloader. This enables
you to upload another bootloader or a combination bootloader/application image.
Verify
The 'c' command will calculate and print the CRC-16 checksum of the flash from base 0x800 or 0x1000
(beginning of application) to the end of flash space.
The 'v' command will calculate and print the CRC-16 checksum of the flash from base 0x0 (beginning of
flash space) to the end of the flash space.
Reset
“r” resets the receiver as if it were just power cycled. “b” boots the main firmware.
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Performing the Update
In almost all cases, you will want to use the ‘u’ command to leave the existing bootloader intact. This has
the benefit of allowing you to recover from a botched upgrade attempt. Press ‘u’ to begin the upgrade.
u
Ready
CC
When, within your terminal software, initiate an Xmodem upload of the new application firmware
image. In TeraTerm, this is in the menu system under File
Transfer
Xmodem
Send…
You can monitor the progress of the upload, though it should take only a few seconds to transfer the
new image.
Figure 8. Xmodem upload status dialog in TeraTerm
When the upload completes, press “c” to verify the firmware checksum matches the value provided by
Grid Insight. If the value does not match, you will need to re-run the firmware upgrade.
If the checksum matches, press “b” to boot into the new application firmware.
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