Portable Control & Measurement Device

Yotam Vit Karinne Attali

Supervisor: Boaz Mizrachi (Zoran)

The PCD: Portable & user friendly

Low-priced

Versatile & multi-purposed

Measure and display results instantly

Store data for later re-evaluation

Control over environment

Customization and extension of feature-set in

HW & SW

Project goals• Self-learning process:– Data sheets, schematics, HW & SW, MPLab

• Assemble & HW debug

• Sensors debug and driver implementation

• Multiple devices production – 9 boards

• Boxes production

• Main menu improvement

• BOM & inventory management

Main Menu

• PCD voltage shows battery value.

• Dcdc opens automatically when needed.

• Dcdc and all related sensors turn off when

temperature sensor is on.

• Each menu has different sensors according

to what is assembled on its board.

Accelerometer

A micro-machined device measuring static acceleration.Output voltage alternates according to 3 dimensional axis.

Pressure

A silicon sensor measuring absolute pressure.Output voltage can be converted to

pressure by:

קומה פישבך13

קומה פישבך1

Buzzer

An electronic audio device working by alternating on and off the signal source given by the PIC, thus creating different frequencies which give a big array of sounds.

for (b=0;b<9000;b++){}for (b=0;b<18000;b++){ if ((b%100)==0) MCU_AUX_BUZZER = !MCU_AUX_BUZZER;}for (b=0;b<9000;b++){}for (b=0;b<18000;b++){ if ((b%190)==0) MCU_AUX_BUZZER = !MCU_AUX_BUZZER;}

UV

A “Shotki” photodiode for UV sensing. The sensor is brought to the surface of the box in order to efficiently absorb all UV rays. Max value in full UV exposure is 3.3.

Shadow

Through window

Full sun light

IR

IR transmitter/receiver.Receiving function is checked using ISR due to high frequencies.

Magnetic

Measures the earths’ magnetic field. Nickel-iron strips change their voltage in presence of a magnetic field. Output voltage alternates according to 2 dimensional axis.

Optic

A CMOS optic sensor that decides on direction of movement by taking 1700 frames per second and comparing them. The sensor needs an external led and prism to work. Output voltage (“1”/”0”) needs to be processed in a FSM. 2 outputs for each direction.

FSM:

Optic

• In order to meet the nyquist condition sampling must occur every 30 microsec.

• Sampling in the main func occurs every 30 milisec.

• There is a need for a short ISR every 30 microsec of the main func.

• Entrance to ISR is made by “Timer 0” .• Only sampling inside the ISR

Optic

ISR must be shorter than the timer, therefore only a minimal number of actions are made inside.

• Sampling sensor output.• Comparing to last value saved in array.• Saving new value in array, only if changed.

FSM and the decision about what direction to move to are done in the main func.

void isr_timer0(void){A=SENS_MCU_MOUSE_X1;B=SENS_MCU_MOUSE_X2;C=SENS_MCU_MOUSE_Y1;D=SENS_MCU_MOUSE_Y2;current_byte = D + (C << 1) + (B << 2) +

(A << 3);if ((current_byte ^ last_byte)) {

OPT[w]= current_byte;last_byte = current_byte;w=(w+1);

}}

Optic

Multiple devices production

• Common malfunctions:–Design mistakes–Assemble mistakes–Defective components–Short/open circuit –Borderline design–Unexpected high “Pic” resistant–Out of range “Pic” input voltages

Multiple devices production• Locate malfunctions:–Visual check–Voltage measure using Scope–Comparison to proper boards–Confirmation with “Data Sheet”–Resistant measurement w/o component–Disconnect (“lifting”) components (“legs”)–SW

Status Report8 7 6 5 4 3 2 1 0 Device No/.

Sensors

+ + + + + + + + IR

+ + + + + + + + + Temperature

+ + + + + + + + + Buzzer

+ + + + + + Pressure

+ + + + + + + + + Accelerometer

+ + + Microphone

+ + + + + + + + + SD

+ + + + UV

+ + + + + + Magnetic

+ Optic

3 batteries missing – fund alternative

Future improvements • Improvements and amplifier for the microphone • Optic sensor:– Add speed detection – integration to the main menu (change timer)

• Clock

• Improvement of buzzer resolution

• Case for buttons

• Additional memory

Future applications • GUI for PC

• IR - remote control

• IR + microphone – volume control

• Optic – digital ruler

• Optic – OCR

• Accelerometer – digital leveler

• Accelerometer – angle gauge

• UV + buzzer – high radiation indicator

Questions?