LIS302DL on a DIP
After 15 years (subjective impression) of research and development, Hardware Monkey inc. is proud to present a fully functioning 3-axis accelerometer on an 8 pin DIP socket. Oooh. The LIS302DL allows digital communication via I2C or SPI. We have tested the I2C interface, though the layout and PCB design also allow for the SPI interface to be used and access to the two interrupt lines on the accelerometer. If you want to use extra pins on your microprocessor to achieve the same thing as the 2 pin I2C interface. Remember to put in the 100KΩ pullup resistors on the clock and data lines! The device was tested using a dsPIC33FJ706GP128 as that's what we had set up from the last big project. Plus the development board (Mikroelektronika LV-33) it is mounted on operates at 3.3V, as a pose to the 5V that our PIC development board works at. The LIS302DL likes 3.3V signal levels. It doesn't like 5V signal levels. Anyways, we read the device ID and display the x, y and z-axis readings, watching them change as we twiddle the accelerometer. Firmware was developed on the excellent and free version of Mikroelektronika's C compiler for the dsPIC.
The board was designed using the Eagle software available from cadsoftusa.com and manufactured at PCBpool. Soldering was done by hand, using the lab monkey and our rinky dinky new Weller PU81 soldering station and lead-free solder. The extra power of the 80W PU-81 compared to our older 40W station seems to make a big difference with lead-free soldering. Especially sticking things onto power planes. Use a narrow (0.4mm) bit and a steady hand.
The LIS302DL is quite a sophisticated accelerometer with added functionality, such as tap detection (set via internal registers) that make it more versatile than earlier models. The digital interface takes the ADC load from your microprocessor and at 8 useable bits allows for a good resolution. The device can be set to scale to 2g or 6g.
LIS302DL on a DIP in action!
Board layout, schematics and library parts can all be downloaded in Eagle format:
LGA14 break out board
An LGA14 break out board was completed for prototyping purposes with the accelerometer. I hadn't come across this footpint and had to draw it into the Eagle library. Hopefully this will be of use to someone: