With the ability to measure 4 remote temperatures using inexpensive 2N3904 type transistors, the MRBW-RTS is ideal for array temperature monitoring. Using several MRBW-RTS nodes allows you to monitor many points on the solar array with all the data consolidated onto the common MRBus network (either wired or wireless). Knowing the array temperature allows you to most effectively cool the array when charging and can indicate hot spots that may be signs of problems with the array or the power trackers. The MRBW-RTS can be connected to a wired MRBus network on the vehicle or, transmitting the data wirelessly, from a single 12V battery or a pair of AA batteries using the CKT-LTC3528. The MRBW-DAQ is a general-purpose data acquisition system containing a high-performance 24-Bit ADC coupled with a very accurate voltage reference and is capable of measuring 16 single-ended channels, 8 differential channels, or any other combination. The ADC can interface directly to a variety of sensors including thermocouples (array temperature measurement), current shunts (array current monitoring), and voltage dividers (cell voltage). Two 12-bit DACs are also available along with 8 general-purpose digital IOs. The MRBW-DAQ can be powered from a wired MRBus network on the vehicle or, transmitting the data wirelessly, from a 12V battery using the CKT-LT3973 or from a pair of AA batteries using the CKT-LTC3528.

For a fully self-contained data logging system, consider the ARD-LTC2499 Arduino shield. This shield contains the same ADC as the MRBW-DAQ, but can be joined with an Arduino board and microSD Shield to make a complete, self-contained data logger.

The MRB-DCCM is a 4-channel isolated current monitoring node with each channel, in its default configuration, capable of measuring up to 5A. These nodes can be deployed to monitor the current into (or out of) each power tracker on the solar array providing greater insight into the efficiency of the solar modules on the vehicle and spotting problems before they become more serious.

The turn-signals and brake lights can be controlled by an MRB-GIO using custom firmware to control the blink rates and respond to control signals over the MRBus network such as "brake activated", "left turn", "right turn", and "hazard lights". The GIO can interface with inexpensive relay modules to enable control of 12V off-the-shelf lighting modules. The MRB-GIO can be connected to a wired MRBus network on the vehicle allowing remote control of its outputs via the driver interface, in response to other events in the vehicle, or even from the chase vehicle!

The MRB-FCM can be adapated to be a comprehensive driver information display. A large font format is available for critical display items, such as speed, leaving plenty of room to display other car data for the driver. Four integrated pushbuttons (with a header for remote mounting) can also be used to interact with the car and the telemetry system. The MRB-GIM2 is a 64-segment LED driver that can interface with up to eight 7-segment LEDs, 64 discrete LEDs, or any combination. This node can be used as a versatile driver information display for things like speed, cruise control status, charge/discharge levels, dashboard turn signal indicators, and error/fault display. The MRB-GIO provides 16 general purpose input/output pins that can be used for driver inputs or simple indicator lights. Examples applications include turnsignal control, cruise control settings and brake switch input. The MRB-GIO can be configured to broadcast its input status over the MRBus network allowing other nodes to react apprpriately (e.g. a separate MRB-GIO configured to control the turn signals and brake lights - see Lights tab). The MRBW-TH is a versatile temperature and humidity sensor platform that can interface to a variety of I2C sensors (not limited to just temperature and humidity). These can be used for monitoring the driver compartment for health and safety reasons and for monitoring weather conditions.

Several options are available ranging from temperature only to low-cost temperature + humidity to high-performance temperature + humidity + pressure configurations. Custom setups are also possible, utilizing any I2C based sensors. Multiple sensors are supported on each node, connected via low-cost 4-conductor phone cable. The MRBW-TH can be connected to a wired MRBus network on the vehicle or, transmitting the data wirelessly, from a pair of AA batteries or from a single 12V battery using the CKT-LT3973.

With the ability to measure up to 4 remote temperatures using inexpensive 2N3904 type transistors, 8 single-ended voltages, or 4 differential voltages (for example, a current shunt) the MRBW-RTS makes a simple battery pack monitoring solution. The MRBW-RTS can be connected to a wired MRBus network on the vehicle or, transmitting the data wirelessly, from a single 12V battery or a pair of AA batteries using the CKT-LTC3528. With a little creativity, multiple wireless MRBW-RTS nodes could be attached to the battery pack, powered from successively higher cells in the stack, providing very fine-grained monitoring of battery voltages and temperatures. The MRBW-DAQ is a general-purpose data acquisition system containing a high-performance 24-Bit ADC coupled with a very accurate voltage reference and is capable of measuring 16 single-ended channels, 8 differential channels, or any other combination. The ADC can interface directly to a variety of sensors including thermocouples (array temperature measurement), current shunts (array current monitoring), and voltage dividers (cell voltage). Two 12-bit DACs are also available along with 8 general-purpose digital IOs. The MRBW-DAQ can be powered from a wired MRBus network on the vehicle or, transmitting the data wirelessly, from a 12V battery using the CKT-LT3973 or from a pair of AA batteries using the CKT-LTC3528.

In addition to applications on the vehicle, the MRBW-DAQ can also be used in a battery characterization system in the lab. By characterizing battery performance outside the vehicle, your team can gain valuable information for strategy decisions required during the race.

The MRB-ACSW is a dual 15A networked switch. In addition to the onboard relays capable of switching up to 15A, two additional outputs are available with integral protection for directly driving external relays. Four logic inputs are also available for control inputs or counters. The MRB-ACSW can be used as part of a battery characterization system to automate the charge / discharge cycling. The I2C-RELAY16 will allow any I2C master to control commonly available 16-channel 5V relay boards. (These typically have SPDT relays down both sides, and an 18-pin, 2-row, 100 mil header). Use them for switching sense leads between batteries in a pack where isolation is of the utmost importance.

The telemetry network on the vehicle can be constructed in a number of ways from fully autonmous, wireless nodes to a centralized computer talking to every node and communicating to the chase vehicle. Various interfaces are available to accommodate any configuration. The MRB-AP is a wireless bridge between wired MRBus networks. If the vehicle uses a local wired network between nodes, the MRB-AP can then be used to transmit the data on the network to/from the chase vehicle, either via another MRB-AP in the chase vehicle or directly to an XBee Explorer connected to a PC. Alternatively, the MRB-AP can be used to receive and consolidate all the wireless traffic from a collection of independent wireless nodes on the vehicle into a single wired network for further processing. The MRB-CI2 provides a USB interface to the MRBus network. It emulates a standard serial port on the USB side sending packet data from the MRBus network to the PC and accepting packet data from the PC to be transmitted on the MRBus network. The MRB-CI2 can be used as the interface between a wired MRBus network and a central computer located on the vehicle.

The MRB-AP is a wireless bridge between wired MRBus networks. It can be used in the chase vehicle to receive wireless data from the solar vehicle, either from individual wireless nodes or from another MRB-AP. The MRB-CI2 provides a USB interface to the MRBus network. It emulates a standard serial port on the USB side sending packet data from the MRBus network to the PC and accepting packet data from the PC to be transmitted on the MRBus network. The MRB-CI2 can be used with an MRB-AP to receive wireless data from the solar vehicle and transfer it to a PC for processing, display, and archiving. The MRB-FCM can be adapated to be a comprehensive telemetry information display. A large font format is available for critical display items, such as speed, leaving plenty of room to display other car data used for making strategy decisions. Four integrated pushbuttons (with a header for remote mounting) can also be used to interact with the display allowing more information to be shown as needed. The small size and easy networking of this display makes it ideal for mounting in multiple locations around the chase vehicle to provide information to every team member involved in racing decisions. The MRBW-TH is a versatile temperature and humidity sensor platform that can interface to a variety of I2C sensors (not limited to just temperature and humidity). These can be used for monitoring weather conditions, and with the appropriate sensor package(s), solar irradiance and other environmental conditions.

Several options are available ranging from temperature only to low-cost temperature + humidity to high-performance temperature + humidity + pressure configurations. Custom setups are also possible, utilizing any I2C based sensors. Multiple sensors are supported on each node, connected via low-cost 4-conductor phone cable. The MRBW-TH can be connected to a wired MRBus network in the chase vehicle or, transmitting the data wirelessly, from a pair of AA batteries or from a single 12V battery using the CKT-LT3973.

MRBFS is a Linux filesystem emulator providing a direct interface to an MRBus network. Incoming data from the network is represented as plain text files in a hierarchical filesystem. Data can be sent to the network by simply writing to certain files and MRBFS takes care of all the protocol.

MRBFS is directly compatible with the MRB-CI2 and XBee Explorer. Most existing Iowa Scaled Engineering MRBus nodes already have MRBFS drivers and the code is completely open-source allowing it to be customized for any requirements.

Using Arduino? The MRB-ARD is an Arduino compatible shield that interfaces to a wired MRBus network. Arduino code that handles the MRBus protocol is also available. The ARD-LTC2499 Arduino shield contains a 24-bit ADC coupled with a very accurate voltage reference. It is capable of converting 16 single-ended channels, 8 differential channels, or any other combination. In addition to measuring voltage, the ADC can interface directly to a variety of sensors including thermocouples and current shunts. The onboard EEPROM can be used to store calibration and configuration information directly on each ARD-LTC2499 board. The ARD-LTC2499 can be used with other Arduino shields to make a simple, yet very accurate, data acquisition system. The ARD-LTC1863 Arduino shield contains an 8-channel, 12-bit, 200ksps ADC. It can be used in various data acquisition applications including battery cell voltage monitoring, array voltage and current monitoring, coloumb counting, etc. Coupled with other Arduino shields, the ARD-LTC1863 can be part of a simple, yet sophisticated, data acquisition system. The ARD-LTC2990 Arduino shield contains two LTC2990 Voltage, Current, and Temperature monitors. These can be used to measure 8 single-ended voltages, 4 differential voltages, and/or 4 temperatures using inexpensive 2N3904 type transistors. Breakout boards for many useful, yet hard-to-prototype parts are available. Some are described below and others are added periodically. Find the complete listing here or contact us if you would like to request a new breakout board. The CKT-LTC2990 is a breakout board for the LTC2990 Voltage, Current, and Temperature monitor. It provides easy access to the pins of the LTC2990 in a standard DIP footprint. The CKT-LTC2997 is a breakout board for the LTC2997 Remote/Internal Temperature Sensor. It provides easy access to the pins of the LTC2997 in a standard DIP footprint. The CKT-LT3973 is an ultra-efficient step-down regulator in a standard 3-terminal footprint. It can be used to replace "7805" style regulators in power sensitive designs. Unlike other 3-terminal switching regulators on the market, the CKT-LT3973 has ultra-low quiescent current. This means that when the load is sleeping or disabled, the regulator draw orders of magnitude less current from the input (typically a battery). In battery powered applications where the node being powered operates on a very low duty cycle, the resulting increase in battery life can be significant.

The CKT-LT3973 can operate up to 40V at the input and provide up to 750mA to the load. Output voltages of 3.3V and 5V are standard and other options are available on request.

The CKT-LTC3528 is an ultra-efficient step-up regulator in a standard 3-terminal footprint. It can be used to convert traditional linear regulator designs ("7805") to run from batteries. Because the CKT-LTC3528 also has very low quiescent current, the power drain on the battery is minimized while the load is sleeping or disabled. Output voltages of 3.3V and 5V are standard and other options are available on request. The I2C-RELAY16 will allow any I2C-enabled microcontroller to control commonly available 16-channel 5V relay boards. (These typically have SPDT relays down both sides, and an 18-pin, 2-row, 100 mil header.) Use them for switching line level or higher current loads with complete isolation. They're not limited to just relays, though - they're an easy way to add 16 channels of logic-level digital outputs to any I2C bus. The MRB-XIO provides 40 channels of digital I/O, an MRBus interface and programmable AVR, an onboard switching regulator to power all of those I/O channels, and an I2C expansion jack all on one board. Useful for anywhere you have a large number of inputs to monitor or outputs to control. The PCA9698 that handles the I/Os allows for pin-selectable direction, interrupt on change, output inversion, and reasonably high currents (10mA source, 25mA sink) on all pins simultaneously.

If you need even more I/O lines, check out our I2C-XIO 40 channel digital I/O expander. Each provides 40 I/Os through the same PCA9698 and switching regulator, but without the built-in MRBus interface of the MRB-XIO. With eight selectable I2C addresses, these boards can be connected together on a single I2C bus to provide up to 320 I/Os. The MRB-AP is a wireless bridge between wired MRBus networks. The MRB-CI2 provides a USB interface to the MRBus network. It emulates a standard serial port on the USB side sending packet data from the MRBus network to the PC and accepting packet data from the PC to be transmitted on the MRBus network. MRBFS is a Linux filesystem emulator providing a direct interface to an MRBus network. Incoming data from the network is represented as plain text files in a hierarchical filesystem. Data can be sent to the network by simply writing to certain files and MRBFS takes care of all the protocol.

MRBFS is directly compatible with the MRB-CI2 and XBee Explorer. Most existing Iowa Scaled Engineering MRBus nodes already have MRBFS drivers and the code is completely open-source allowing it to be customized for any requirements.

Frequently Asked Questions

Q: How do I set up an MRBus network?
A: Getting started is easy. Please read our step-by-step tutorial over here.

Q: Will you sponsor our team?
A: Having been on a team in the past, we certainly understand the appeal and desire for cash donations and free stuff. While we are not in a position to make cash donations at this point, we are willing to work with your team to arrange product discounts in return for exposure to other engineering students and faculty on campus and/or a spot in your sponsor listings. Send us a proposal and we will see what we can do.