BASIC TOPIC

Portable sensor box

The goal is to design a sensor box that is used to give diagnostic information from outdoor robots, cars, motor cycles or other devices. The device measures the forces, acceleration and vibration experienced by a device, the temperature of critical parts such as motor, brakes, batteries or motor controllers, as well as existing ambient temperatures and humidity.

The device logs sensor values into an SD memory card for a long period of time. The logged data can then be extracted to a computer via serial port. The sensors include a three axis accelerometer, three temperature sensors and a humidity sensor.

The device works with a single 1.5 volt battery i.e. the current consumption must be minimized and the operation voltage must be pumped up from the battery voltage. The device contains also an LCD display and some buttons that are used to create a menu system. They also enable reading current sensor values.

The basic requirements for the device are the following:

• The serial interface works from MCU to PC. The unit sends all all logged sensor data to the PC in a readable form. The data is read in PC with some regular ASCII based terminal program such as Hyper Terminal. Data must be readable from SD card or online from the sensors.
• The serial interface works from PC to MCU. At least menu must be possible to be controlled via PC.
• Menu buttons can be used to operate the device. User must be able to start and stop logging and data transfers from SD-card to PC via menu.
• LCD display shows menu and some information, at least the current sensor values and the amount of logged data.
• The data is saved to an SD-Card.
• The system stores also maximum and minimum values from sensors.
• The device gets 3.3 volt operating voltage from a 1.5 volt battery.
• The device utilizes power comsumption possibilities. MCU and all the components must be in a power consumption mode or off when not used.
• Device must measure acceleration, temperatures and humidity. At least one sensor must be read via AD-converter (accelerometer), at least one sensor must be read via i2c bus (temperature sensors).

These are also the basic grading points. Additional points can be received from additional features that demonstrate utilizing different features of the MCU. You may include also following optional features:

PC data visualization for measurements

The Portable sensor box will be based on an Atmel ATmega series microcontroller (MCU). The students are recommended to use ATmega32 controller. The control module is required to contain the following on-board components:

ATMega MCU

some buttons for operating the Portable sensor box

LCD display

RS-232 interface for PC connection

JTAG connector for programming and testing the MCU

electronics needed to support required functions

Each group will receive

• The serial cable connector
• Accelerometer module (2,54mm raster socket (Put pin header to your PCB))
• LCD display (optrex F-51553)

---

Serial cable connector, 5 pin 2,54mm raster socket for pin header. Notice 2 empty orientation slots.

---

Accelerometer module, 8 pin 2,54mm raster socket. Put pin header to your PCB.

---