SubPos Ranger: Indoor Positioning System
SubPos Ranger: Indoor Positioning System
The SubPos Ranger allows you to accurately measure distance or obtain your position indoors for all hobbyist robotics applications.
The SubPos Ranger allows you to accurately measure distance or obtain your position indoors for all hobbyist robotics applications. Read more
About this project
What is the SubPos Ranger?
The SubPos Ranger is an open source development system for accurate distance measurement and positioning that's ready for manufacture. The Ranger has been designed as a flexible radio frequency platform for hobbyist robotics and educational applications, to enable you to realise your project’s positioning potential. This flexible design can even allow you to perform passive motion sensing to augment your existing positioning systems!
- Supports 2D and 3D Positioning – not just x and y, but z also.
- 2.4GHz ISM Spectrum – supported worldwide.
- Standards Compliant Hardware – supports 802.15.4 and can also utilise Zigbee or 6LoWPAN communication protocols.
- Reconfigurable RF Chipset – enables many different 2.4GHz ISM applications.
- Firmware Updates over USB – no need for any extra programming hardware.
- Open Source Hardware and Software – hack, repurpose and play to your heart’s content.
- Modular Design – the Ranger allow all sorts of connectivity options. You can connect it to anything such as a Raspberry Pi via USB or GPIO, Arduino or to your smartphone via Wi-Fi.
- Low Level Raw Data and Parameters – access to all low level measurement data and parameter tweaks are available to discover interesting new applications (such as motion detection).
- Node Position Calibration – get the position of nodes automatically; no manual fixed node measurements required.
- 9-Axis Accelerometer – the client expansion board contains a 9 axis accelerometer for increased positioning accuracy.
What Can It Do?
The distance measurement or proximity capability of the Ranger Boards achieves accuracy of up to +-10cm in line of sight conditions. When combined with the client expansion board and Teensy module, the position is calculated completely on the client without any external processing required.
When operational, the client will output its position and control information much like a GPS receiver, to a serial UART/GPIO or via USB. As such, the system allows you to develop an autonomous platform which always knows where it is indoors. You will now be able to eat every piece of cat hair with your modified robot vacuum, or guide your sustenance procurement bot 2.0 to the fridge to gather lemonade.
The boards also support a remote ranging function that can be used to monitor the movement of another board. This means you can use an additional board to track the motion of another device, without being physically connected to it. If you order the 5 board positioning kits, you can use one of the boards to track another board and still have 2D positioning around 3 nodes, or add an additional board if you want 3D remote ranging.
The RF chipset on board also provides a true 2.4GHz ISM transceiver interface, this means that the Ranger Board is completely reconfigurable and not limited to only standards and positioning purposes. Because of this, you could also use it in an array of different RF applications such as radio modems, motion detection or wireless sniffing devices.
How Does the Ranger Work?
The Ranger Boards support a software load that uses the 802.15.4 standard to communicate information between each board. When determining distance between two Ranger Boards, they initiate a ranging handshake over 802.15.4 to then perform a distance measurement.
The Ranger Boards accurately determine the distance between one and other through phase shift/difference measurement and accurate timing techniques in the onboard Atmel AT86RF233 chipset. This is similar to how laser range finders work, except instead of light it uses 2.4GHz radio frequencies. The multiple antennas on board allow for multiple out of phase measurements to mitigate multipath effects, to best determine the distance between the Ranger Boards.
The client performs this measurement operation multiple times per second to all visible nodes in range. It then uses the node positions and these distances to determine its own position in relation to these nodes through trilateration.
Optional Wi-Fi Support
The expansion boards also support the addition of an ESP8266 module if you would like to enable Wi-Fi for you to connect to a multitude of devices such as your smartphone. The Wi-Fi module can be used to transmit data to a local server if you are using the Ranger Board for other purposes, such as motion detection, or using it as a Zigbee to Wi-Fi gateway.
One expansion board without Wi-Fi is included to convert a Ranger board to a client when you back the positioning system reward (and add a Teensy), however if you would like to support Wi-Fi on the Ranger Boards configured as a node, you can order additional expansion boards and the ESP8266 (ESP03) modules separately.
The positioning software libraries will also support the SubPos Wi-Fi Positioning System standard, when an ESP8266 Wi-Fi module with appropriate firmware is attached to both the client and nodes. The regular version of the SubPos Ranger Positioning System only supports up to 16 nodes, the standards supported version (when you add a Wi-Fi module) supports virtually unlimited nodes.
Ranger Board Technical Specifications
- Atmel ATxmega128A4U Microcontroller
- Atmel AT86RF233 RF Chipset
- Antenna Diversity (Phase/Multipath)
- RF shield (not pictured) is included
- Built-in Ceramic Antennas
- USB CDC Serial Connection (No Driver Required) for Distance Output/Control
- USB Firmware Update Bootloader
- Dual UART Serial (2xTX/RX) for Distance Output/Control
- 8 GPIO Connections
- 3 LEDs
- USB 5V or External 3.3-16V Supply with Reverse Polarity Protection
- Highly Stable TCXO
- 35mA @3.3V during normal usage
- Dimensions 46x55 mm
Expansion Board Technical Specifications
- InvenSense MPU-9250 Nine-Axis IMU
- Teensy 3.2 Support
- ESP8266 (ESP03) Support
- ESP03 Power Control (Easy Reboot for Firmware Update and Watchdog)
- UART Serial Position Output From Teensy
- GPIO Output From Teensy
- External 5-16V Supply with Reverse Polarity Protection
- Dimensions 46x39cm
How Far Has The Ranger Come?The Ranger Board is a complete design ready for manufacture, having already gone through various prototype revisions. The software is also operational and almost ready for public release. The Kickstarter funding will be immediately used to begin production at the scale that allows us to bring it to you for the lowest price.
We are husband and wife team interested in the hobbyist and education sectors. We spend many of our spare hours hacking away for fun and to develop learning programs for school students.
- Wi-Fi Module (ESP-03) - $6AUD
- Expansion Board Without IMU - $12AUD
- Expansion Board With IMU - $25AUD
- Teensy 3.2 Module - $34AUD
- Extra Ranger Board - $54AUD
- Blank Ranger Board PCB - $9AUD
Risks and challenges
While the final production ready hardware design is complete and awaiting manufacture, there are always significant challenges when going to production and having it ship on time. To counter this, the Ranger will be manufactured and parts sourced as locally as possible. Blair Wyatt has experience, contacts and constant engagement with the Australian electronics manufacturing industry. This allows for oversight and accurate price estimation to ensure the product can be delivered on time and on budget, with the strictest quality control. All things going to plan, the Ranger will be completely Australian made.
While the ranging and positioning software is completely operational, there is always room for improvement and bug fixes after the hardware is released. With the ability for the modules to update their firmware via USB, end users will be able to load firmware onto their hardware as soon as new updates are released. They can also change the Ranger Board and client code as they wish, as it’s all open source!
As for shipping, the biggest challenge will be managing the large and varied list of destinations around the world. While Sue has a lot of exporting experience, we first need to wait and see how the campaign pans out before deciding how things are managed in that department. However, we do have plans in place for the Australian and US contingents and will manage these first. We ask if you are from elsewhere around the world for your understanding if there is a minor shipping delay. If you live in or want to visit Melbourne and order an early hand soldered positioning setup, we’d be more than happy to organise pickup or hand delivery so you are the first to get it.Learn about accountability on Kickstarter
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