neoPLC 9-DoF IMU Board

Based on the Bosch BMX055, this sensor board provides a 9 degree-of-freedom inertial measurement solution in the neoPLC form factor. Adjustable full-scale range and Internal filters make this sensor a great choice for most common IMU needs. Easily adjustable internal filters ensure the data this module outputs are immediately useful – no need to compute filtered data on your microcontroller. The accelerometer has an adjustable range from +/-2 Gs to +/- 16 Gs, and with bandwidth to 1000 Hz. The gyroscope has an adjustable range from +/-125 deg/s to +/- 2000 deg/s, and with bandwidth to 500 Hz. The magnetometer outputs data at up to 30 Hz.

neoPLC – “professional prototypes, no compromises”

• Easy wiring – all our boards use i2c serial, so no matter how many boards are in use, they share the same four wires – so you can be connected and running in no time
• Easy chaining – the boards share the same serial wires– allowing trouble-free connection of multiple boards – even boards with different functions!
• No ‘extra’ pins are broken out – you never have to dig through datasheets to connect these boards
• The boards can be stacked for easy testing, or soldered edge-to-edge creating a professional rapid-prototype for demonstration and small production products
• All code is contained in a single (open-source) library, but only the code you need is compiled to your micro-controller, saving space and increasing speed
• All boards operate from 3 to 5.5 V – safe with most common microcontrollers
• Uniform pricing – all boards of all functions are $20 – easily estimate total project costs
• Every board is tested for performance before shipping

Wiring

First, provide the neoPLC boards a common ground (GND) and a power bus V+ (anything from 3-5V for all our boards!). Secondly, i2c uses two lines to communicate – a ‘Serial CLock’ (SCL) bus and a ‘Serial Data’ (SDA) bus. Simply connect these to the appropriate pins on your microcontroller and neoPLC board, and you’re all set. Can’t be much easier than 4 wires! One more, very important thing – you must connect a ‘pullup’ resistor (between 1kOhm and 5kOhm) between the SCL and SDA bus. GND, V+, SCL, and SDA are clearly labeled on all neoPLC boards. The SCL and SDA pins on common microcontrollers are listed in the table below:

How does i2c work?

One of the key benefits of the neoPLC boards is the simple wiring. Nearly all modern microcontrollers include a dedicated i2c (pronounced ‘eye-squared-see’) port. Standing for ‘inter-integrated-circuit’, i2c is clever as allows many integrated circuits to share the same communication and power lines – the ‘bus’. The SCL clock is controlled by your microcontroller, it provides a steady march of pulses while communicating to ensure no data is missed by either component. While the SCL steadily pulses, the microcontroller and neoPLC board take turns sending and receiving data over the SDA bus. Each board has a name in i2c called its ‘slave address’. When the microcontroller sends a specific board’s name out on the SDA bus, that board alone will respond. So, many boards can share the same SCL and SDA bus, but only if they have unique addresses – otherwise everyone gets confused about who should be speaking! To allow multiple identical boards on the same bus, we provide adjustable address ‘pads’ on most boards: by cutting the same trace near A0,A1,etc. and putting a small dab of solder on the other side of the pad, the address is changed. Multiple combinations of cut/uncut traces allows several boards to be connected.

Downloads

Datasheet and library is available in the Right Sidebar. Library was derived from code by Kris Wiener.