April 5, 2014 Jonathan Valvano EE445M/EE380L.619. Motor Interfacing• Motor physics• Transistor-level interface19.1Ya Brain,who pluggedthis typewriterinto our TV?J VwPinky,are youponderingwhat I'mpondering?Digital InterfacingApril 5, 2014 Jonathan Valvano EE445M/EE380L.619.2VOLis defined as the voltage at maximum IOLFamily Example IOH IOL IIH IIL fan out Standard TTL 7404 0.4 mA 16 mA 40 µA 1.6 mA 10 Schottky TTL 74S04 1 mA 20 mA 50 µA 2 mA 10 Low Power Schottky 74LS04 0.4 mA 4 mA 20 µA 0.4 mA 10 High speed CMOS 74HC04 4 mA 4 mA 1 µA 1 µA LM3S/LM4F 2mA-drive LM3S811 2 mA 2 mA 2 µA 2 µA LM3S/LM4F 4mA-drive LM3S811 4 mA 4 mA 2 µA 2 µA LM3S/LM4F 8mA-drive LM3S811 8 mA 8 mA 2 µA 2 µA Electrical specifications• See Chapter 24 of TM4C123• 5V tolerant?• PD0, PD1  PB7,PB6All GPIO signals are 5-V tolerant when configured as inputs except for PD4, PD5, PB0 and PB1, which are limited to 3.6 V.April 5, 2014 Jonathan Valvano EE445M/EE380L.6Motor Physics19.3WireElectricalCurrent,IMagneticField,BElectrical ModelRLemf-+IBElectromagnet+-+-WireIBNorth SouthFFNorthMagnetSouthMagnetCoilIIFBrush BrushICommutatorsFNSCoilFStatorRotorApril 5, 2014 Jonathan Valvano EE445M/EE380L.6Darlington Transistor• TIP120 (NPN)• hfe= 1000• Ice= 3A19.4LM3SLM4FPWM0PWMPWM050 200125 125200 50H LH LH LH L2N2222orTIP120RDC motor+V1N914-+RLemf-+bPWM0PWM0Ib= Icoil/hfe= 1A/1000 = 1mARb≤ (VOH-Vbe)/Ib= (3-2.5)/1mA = 0.5 kRb= 100 VCEdepends on currentApril 5, 2014 Jonathan Valvano EE445M/EE380L.6MOSFET Interface• VGSturns on• VDSsmall• IDSlarge19.5PN22221 kLM3SLM4FPortIDCoil+V1N914-+RLemf-++V10 kIRF540IRF522PN22221 kLM3SLM4FPortIDCoil1N914-+RLemf-++V10 kIRF9540FQP27P06GDSGSDApril 5, 2014 Jonathan Valvano EE445M/EE380L.6H-bridge Interface• Both directions• VOH= +V-1.4, VOL= 1.219.6L293+5A+V361A2A1Y2Y2711,2EN+54,5168+V1N914Q1Q2Q3Q4A1Y 2Y36845L293April 5, 2014 Jonathan Valvano EE445M/EE380L.6H-bridge Interface• PWM controls power• Out controls direction19.7 uC 1 , 2 E N 3 , 4 E N 1 A 2 A 3 A 4 A +5+519271015+516451 2 1 3+ 9 8 + 9 +9 +9+9 3611141 Y 2 Y 3 Y 4 Y L 2 9 3 1N914PWM Out PWM Out See L6203.pdfApril 5, 2014 Jonathan Valvano EE445M/EE380L.6H-bridge Interface• One Port is PWM controlling power• Other port controls direction19.8April 5, 2014 Jonathan Valvano EE445M/EE380L.6Servo Motor• Simple digital interface (built in controller)• Duty cycle controls angle19.9April 5, 2014 Jonathan Valvano EE445M/EE380L.6Servo Interface• Needs its own +5V regulator• Duty cycle controls angle19.10Command waveforms60o30o0o0.5 ms1.5 ms2.5 ms20 msIn OutGnd7805VinServoPowerGroundCommand+5V9S12PWM10F10F+-+-AngleuCPWMApril 5, 2014 Jonathan Valvano EE445M/EE380L.6Servo Software• Duty cycle controls angle19.11Summary• Be careful of the currents• Sensors are noisy• Time lag makes it unstable• Component testing• Visualization and controlApril 5, 2014 Jonathan Valvano