leader: amos friend hardware specialist:luke noschese software specialist: jacob longwill assistant:...
TRANSCRIPT
Leader: Amos FriendHardware Specialist: Luke NoscheseSoftware Specialist: Jacob LongwillAssistant: Ryan Trump
Power SystemsBy: Team Leroy Jenkins
Understand the ProblemNimH BatteriesCharge and discharge graphsHardwareSoftwareSummaryReferencesQ&A
OverView
Power SystemsClean accurate power to respective
components Safeguard against destroying components with
too much powerUnderstanding power output of the batter as it
drainsDisplaying battery lifeUse on-board LED to change color depending
on battery life.
The Problem
Battery NiMH (Nickel-Metal Hydride)LM2940 or 4941 LDO Regulator (5v Volts)MCP1702 or 1700 LDO Regulator(3.3 Volts)2x 4.7KΩ5 Capacitors of different values
Components Needed
NiMH BatteryNickel–metal hydride
batteryDoes not have Memory
Effect as NiCd did7.2v battery
Output can go as high as ~9.5v when fully charged
3000mAh battery6-cellEach cell
1.2v3000mAh
Discharge Graph of full 7.2v NiMH
Single 1.2v cell charge graph
Single 1.2v cell discharge graph
Different groups have different 5v and 3.3v regulators
Use only two voltage regulators1 – 5v regulator1 – 3.3v regulator
3 outputsDirectly from Nimh battery5v output3.3v output
Hardware
Battery DisplayVoltage Divider
If full battery voltage is supplied it will destroy the port
Divide voltage in halfMultiply by 2 in code
To display correct voltage on LCD
Remember to ground the board and battery to a common ground
Large capacitor is needed after 5v regulator for rapid power drain from servo
Hardware Wiring
LM2940 LDO Regulator 5 VOLTS @ MAX 1
AMP MAX INPUT 26VLOW DROPOUT
VOLTAGE500mV @ 1A
LM4941 LDO Regulator5 VOLTS @ MAX 1
AMP MAX INPUT 26VLOW DROPOUT
VOLTAGE250mV @ .5A
MCP1700-3302 LDO Regulator3.3 VoltOperation range
2.5v-6vOutput current
250mALow Dropout Voltage
350 mV typical @ 250 mA (VOUT = 2.5V)
Looks similar to a transistor
MCP1702 LDO Regulator3.3 VoltOperation range
2.8v-13.2vMax out 250mA Low Dropout Voltage
625 mV typical @ 250 mA (VOUT = 2.8V)
Looks similar to a transistor
Flowchart for battery output
Software
Varibles#define VBMIN 500int VBATT;
FB_RGB_ENABLE;FB_RGB_ON;Call Batcheck In Forever Loop
Software Code
void BATCHECK(void)
ADCSC1 = 10; // start 11-bit ADC on PTD3
WAITFOR(ADCSC1_COCO); // wait for conversion complete (new technique)
VBATT = ((((ADCR * 500)/1023)*2));
if (VBATT >= VBMIN && VBATT < VBMIN*(3/2))
FB_RGB_BLUE = 0;
FB_RGB_GREEN = 1;
FB_RGB_RED = 0;
BatCheck
else if(VBATT < VBMIN)FB_RGB_BLUE = 1;FB_RGB_GREEN = 1;FB_RGB_RED = 0;motorDC = 0;
else
FB_RGB_BLUE = 1;FB_RGB_GREEN = 0;FB_RGB_RED = 1;
BatCheck Continued
Analog to Digital Converter
ADC Register
PROBLEM STATEMENT DISTRIBUTING PROPER VOLTAGE TO VARIOUS PARTS OF THE
SMART CAR MONITORING BATTERY STATUS
HARDWARE REQUIREMENTS/CONCEPTS INTERFACE
SOFTWARE DESIGN CODE
Summary
250 MA Low Quiescent Current LDO Regulator." Microchip Technology Inc. Microchip Technology Inc., n.d. Web. 11 Mar. 2014.
"ALIMENTAZIONE." ALIMENTAZIONE. N.p., n.d. Web. 11 Mar. 2014.
"L4941 Very Low Drop 1A Regulator." STMicroelectronics, n.d. Web. 11 Mar. 2014. "LM2940/LM2940C 1A Low Dropout Regulator." Texas Instruments. Texas
Instruments, n.d. Web. 11 Mar. 2014.
"Nickel–cadmium Battery." Wikipedia. Wikimedia Foundation, 28 Feb. 2014. Web. 11 Mar. 2014.
"PDIP | ChipKIT Development Platform." ChipKIT Development Platform. N.p., n.d. Web. 11 Mar. 2014.
"Voltage Divider." Wikipedia. Wikimedia Foundation, 03 JulY2014. Web. 11 Mar. 2014.
MCF51JM128 Reference Manual Notebook reference CET 335 lab 7 Analog to Digital Input
References
Any Questions?