Turn-key PCB assembly services in prototype quantities or low-volume to mid-volume production runs

Home made 9 DOF IMU

Inertial measurement units (IMU) are commonly used where position, motion information must be processed. It is commonly 9 degrees of freedom (DOF) modules used that include LSM303 3 axis accelerometer and 3 axis magnetometer, ITG-3200 3 axis gyro. These are considered enough for precisely calculating position of board carrying all sensors. Amandaghassaei was working on project where orientation information was needed. So instead of purchasing available board, he built one which saved a bit of money, but mos importantly had all he needed. He included Atmega328p microcontroller which reads all sensor data and then can send it through I serial interface. He made 6 pin header to accept standard FTDI interface module. PCB was fabricated by using milling machine. Milling and soldering was a bit challenging since footprints of both sensor chips are really tiny. Continue reading

Learning about accelerometers and gyroscopes

Accelerometers and gyroscopes are commonly used sensors where some sort of balance is needed. Combination of both in one board is called IMU (Inertial Measurement Unit). You will find one on flight controllers, balance modules and in many other areas. If you are going to build something from scratch then you should know some background information on how to interpret readings and how to use them in control. Gadget Gangster have shared pretty good instructable where he explains how to interface IMU device to microcontroller and how to use this data to get desired results. As example he uses Acc_Gyro board with LIS331AL triple axis accelerometer and LPR550AL dual axis gyroscope. He goes through some math while explaining how to determine orientation of IMU using either only accelerometer data or combination with gyroscope readings. Plus gyroscope gives some clue about rotation around one or another axis. SO if you are thinking of building inertial system, you should do your homework and understand hos things work. Continue reading

The High Speed Rocket acceleration logger

You’re always fascinated with the rocket and you’ll try to get it no matter what cost it takes? However, do you ever know how fast the rocket will blast off above the ground, every time you launch it from the ground? Well, if you have no idea about it and you’re desperate to find out the truth, then it’s about time for you to build the high speed rocket acceleration logger! So, what’s the main purpose of this rocket acceleration logger? Ok, this little buddy has the ability to collect and record data from a freescale mma7260, a 3-axis accelerometer. After the microcontroller has collected the require data, it stored in 32k of EEPROM on a 24c256. The rocket accelerometer logger is built around the popular Attiny13 microcontroller and it’s small enough that you can fit it into the nose-cone of the rocket without any hassle at all! A small 3.6v Li-ion battery can power the rocket accelerometer logger (The battery could be the largest part of the circuit!). It would be even better, if you’re able to get a… Continue reading