Razor IMU Enhancement requests: surface ADC pins, i2c, SPI

Archive New Product Ideas
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I got my Razor IMU working today (SEN-10736). Thanks to SparkFun for this useful board. It’s amazing what’s possible now with 3-axis chips.

As always, there is room for improvement :slight_smile: Here’s my wishlist. The expansion I/O on the Razor is “a little” limited. So many AVR pins are not connected. All that’s needed are a few more pads and holes around the chip for it to be an awesome basis for many projects. I would like to wire a bunch of these together along with some additional sensors for a motion capture system, but with the current Razor I/O situation I would have to use something else for some of the nodes.

Specific requests (in order of preference):

  1. Provide access to SPI SS pin (Slave select). This would allow interfacing SPI devices. The other SPI pins are already on the programmer header so this would just need to be one extra hole/pad (notice there is space for 2 extra pads between the AVR and the programming header).

  2. Provide access to AVR ADC pins and some general data pins would be very useful too. E.g. I would like 5 ADC pins so I could make a VR glove with this and 5 flex sensors. Also having access to one or two extra data pins would make it possible to interface the USART to your RS458 transceiver breakout while potentially still having SPI and I2C available).

  3. Connect pin 15 (DRDY) of the HMC5883L magnetometer to an interrupt pin on the AVR. The magnetometer is slow to acquire a measurement and DRDY is used to signal that the data is ready. To achieve a tight constant sample rate it would be useful to have access to this signal. Less important (to me anyway) but also useful would be the interrupt pins on the Accelerometer and Gyro. FreeIMU gives access to these pins for example (http://www.varesano.net/projects/hardware/FreeIMU).

  4. Provide access to I2C pins, so we don’t have to solder directly on to the AVR like this poor guy:

http://trandi.wordpress.com/2011/01/03/ … o-arduino/

Quoting TRANDI: “Sparkfun guys, if you do read this, then pleeeease, do add a simple connector on this board for the I2C bus !”

Thanks for reading!