STM 32 programming

https://www.youtube.com/watch?v=VlCYI2U-qyM&ab_channel=Phil%E2%80%99sLab

 

 STM32 can be programmed via

1. Not clear: Serial wire debug = SWD
2. Not clear: JTAG
3. DFU= Device firware upgrade 
1. ( No provision of setting break points in DFU mode)
2. Use application note AN3156 
3. STM32 Cube programmer software use elf file as input
4. STM32 Cube programmer can upload using 
1. STLINK
2. USB
3. UART
5. Boot zero pin to be pulled to high and restart the MCU to put the MCU in the DFU mode.
6. After flashing the elf file to the MCU using the STM32 Cube programmer, pull boot 0 pin low, restart the MCU
   
4. Not clear: Via USB = You have to write your own boot loader for this.
   

DynCont#5 Fixed and relative frames of reference in high speed shafts

1.  We always measure the speed only in the fixed frame of reference, inertial, non accelerating, constant velocity.
2. It is easier to do integration in ground fixed, inertial frame of reference.
3. But for a whirling shaft / tumbling body, the mass moment of inertia along the x axis of fixed frame of reference keeps changing due to the tumbling of the disk,even though the disk is rigid.
4. For an axis system that is aligned to the disk at a particular instant in time, not fixed to the disk, the mass moment of inertia along the x axis of the aligned system is constant.
5. But it is difficult to do time integrations along this axis system that is aligned to the disk 
6. Again, we are only measuring with respect to ground fixed reference system. That value, we are expressing in terms of an axis system that is aligned to the disk at that particular instant of time. This is only to use the inertia defined in the disk aligned axis system. With this kinetic energy, we can write the Lagrange governing equation and then derive the fundamental equation of motion. 
   

Skills

Mathematical modeling

1.  Development of physics based models for mechanical systems from fundamental equations.
2. Development of plant models using system identification techniques from test data with various control inputs (Step, impulse, sine sweep, PRBS)
3. Development of performance augmentation controllers / Stabilising controllers using
1. PD
2. PI
3. PID
4. LQR
5. State space control
4. Development of simulation models in 
1. Python using numpy/scipy
2. Matlab with Simulink.
5. Tuning of controllers using the simulation models

Embedded programming /  Electrical schematics / PCB

1. Implementation of control algorithms in C for TI MCU / AVR MCU / C2000 DSP
   
2. Design of electrical schematics for controllers and power circuits
3. Design of signal conditioners for ADC and DAC
4. Simulation of electrical schematics using LTspice/Falstad
   
5. Design of PCB (low speed upto 5kHz) 

 Mechanical design

1. Design of test rigs using Solidworks : Dimensioning/TOleranceing GD &T as per ASME standards
2. Optimising design for assembly and manufacturability.
   
3. Design of sheet metal structures for equipment , test rigs and protective enclosures.
4. Design of welded structures / frames
5. Follow up : Fabrication of machined parts : CNC turning center / VMC machining center.
   
6. Follow up :  3D printing (ABS/PLA/PCA)
   

DynCont#5: Z transform, Phils Lab, DDorran

Phisl lab

1.  Z transform is better than Fourier transform because it can do 2 things:
1. Check the stability of the implemented difference equation
2. See the frequency response of the system, that the difference equation represents
2. Z transform based stability check: Simple, replace y[n-1] by z^-1 Y and form the Z transfer function and check the location of poles . Zeros can be out side the unit circle for stable system
3. Z transform based frequency response z^(-k) = e^(-j theta k), where theta  = 2*pi*f/fs. Maximum value f can take is fs/2 so maximum value theta can take is theta = pi. 
4. For DC gain, omega is zero so z = 1
5. For high frequency gain, z= -1

 DDorran

1. Z transform is used to detect the presence of exponentially increasing or decreasing components in the signal
2. By identifying the increasing or decreasing oscillations in the impulse response  of a system we can determine if that system is stable or unstable
3. x[n] is a signal with different values for different n. z^(-n) is also a signal for different values of z. Multiplying individual values of the 2 signals and adding them is basically taking correlation of 2 signals. Higher the correlation, more is one signal present in another signal
4. Correlation is the measure of presence of one signal in another signal.
   
5. When taking correlation of 2 signals, note that if second signal is constructed using z = 1, then we are basically taking the DC value of the first signal. Also see 4th point of previous stack.
6. Z is e^(-sT). Value of the z transform at z = 1 in the plot with z values as x axis is the DC value of the signal.
    

New things he did.

1.  Started saying 2 word sentences in the second week of July 2022
2.  Started saying 3 word sentences in the second week of July 2022, like "Mukesha Amma kupudranga!" to Mukesh who was playing inside.
3. Went to Priya office for full day without going to school so that me and mother can go to Vaniyambadi for Manju funeral. Next day, he asked mother to go to shop and me to go to office so that he and Priya will be alone in the morning and she will take him to office in Bus rather than go to school.
4. Started saying all options other than school. "Priya, Bus train auto polama?"
5. Started identifying a train when we cross a train track near BEML gate and started asking shall we go in train whenever we cross BEML gate.
6. Started adding his own words into conversations : When Priya told me to buy chocolate and cake from behind on the bike, I asked her to repeat as I could not hear what she told. Him, sitting, inbetween told, "Chocolate, ice cream, cake". 
7. When we go to drop Priya in the morning, he starts crying that he wants to take his bag too. So that he can take his bag and go to Priya office rather than school.
   

Notes Random

1. Best drill bits to buy, even if you are drilling rocks: PDC = poly crystaline diamond compacts
2. Why Tungsten Carbide drill bits are better than HSS drill bits?
1. Tungsten carbide drill bits have to be sharpened only by diamond wheels, so their sharpening is done on good machines whose angles are controlled precisely. So they make better drill bits
2. HSS drill bits are cut in normal grinding wheels, so their angles may not be as precise and process may not be strictly controlled. This results in poorer drill bits in the end
   
3. Both Cobalt and Nickel are used as binder in Tungsten Carbide drill bits. When nickel is used, the bit is slightly magnetic. When cobalt is used ?
   
4. Cobalt has higher thermal expansion and so when Cobalt binded Tungsten Carbide drill bits are used for long, due to thermal expansion, they may fail.
5. Always have UV seals next to the commutator brushes in the motor. Constant sparking of the commutator brushes give out UV light and the light damages the polymer cage of the bearing and the grease.
   

 

DynCont#4: SVD, 3Blue1Brown

1.  If determinant is zero, the transformation matrix collapses the input vector to a point in the output vector space
2. A span of the vector is a line , infinite passing through the vector in both the directions. A vector can be multiplied by a constant number and the head of the vector will be somewhere along the line for different constants 
3. Matrix multiplication:
1. Row wise picture, conventional computational approach
2. Column wise picture
3. Transformation from one vector space to another vector space approach
4. Will be edited after listening to the lec again.