One Liners

 

Scale Kicad Footprint

awk '{{for(i=1;i<=NF;i++){if($i~/\((start|end|center|at)\>/){$(i+1)=$(i+1)*0.6667;$(i+2)=($(i+2)*0.6667)")"}}};print}'

留言

張貼留言

這個網誌中的熱門文章

EIE3105 / EIE3106 Robot Car Info (2024 Jan - Apr) - Integrated Project

圖片
  PolyU EIE3105 / EIE3106 - Note (Robot Car) - Integrated Project 2024 ( Jan to Apr 2024 )   PolyU EIE3105 / EIE3106 Info (EEE) 2023/2024 S2 - Integrated Project -  Some Note & Info *  ( 30 Jan 2024 )   (Click the photo to enlarge it) ----- -----  * Important Note *  ----- ----- 1) Please note that each robot car is with a unique number assigned. Please do not exchange the car with your classmates, without approval. 2) Please note that the electric current or the power output of the I/O (Output pin) of microcontroller  unit (MCU) STM32F103 is limited. Over electric-current driving will damage the circuit and the I/O pins of the MCU. So please make sure to have resistors to limit or protect the I/O pins of the MCU ("+" pin, driven by the output of MCU). (from https://www.eleccircuit.com/current-limiting-resistor/) Some students connect the LEDs and the output pin of the MCU, to drive the LEDs without any resistors to limit the electric current. Some students reported that
閱讀完整內容

PolyU EIE3105 / EIE3106 (2022-2023) EIE JoyPad & MCU Control PCBs - Important Note (Robot Car) - Integrated Project

圖片
PolyU EIE3105 / EIE3106 Real PCB Photos  2022/2023 S1 to S2 - Integrated Project - Important Note * ( 15 Mar 2023 ) ----- ----- * Important Note * ----- ----- Some students reported failure on MCU or USB port burnt in short circuits (pins among 3.3V and GND). Possible damage causes: 1) The capacitor of C2 on the Blue-Pill MCU adaptor board is too small. It should be 100 uF or larger (recommended to use 220 uF, 10V) 2) Short circuit occured because of bad soldering or wrong connections. Please check your regulator outputs Vcc. It should be 3.3 V. Is it 3.3 V? Many students reported that the Vcc is 6V to 7V from the 3.3V regulator because it has been burnt due to short circuit. Please don't keep asking for new blue pill MCU board if you haven't checked the Vcc voltage!!! We have purchased many pieces of new AMS1117-3.3V. 3) The two 3.3V power were turned ON with: a) Battery power is turned ON to have a regulator to provide 3.3V AND b) USB port is connected to USB dongle to gene
閱讀完整內容

PID Speed Control

圖片
    In this post, all codes are NOT tested. the PIDs are not tuned yet. Derived wheel rotation speed from Wheel Count Have you ever calibrated the wheel counter? Let me give you some data. 1. one revolution = 60 counts 2. wheel diameter = 56 mm 3. sampling time = 2.5 ms What do you think about the MAXIMUM change in count per 2.5 ms? Doing a simple arithmetic, you will learn that it is not likely to exceed 15 counts per 2.5 ms. In fact, 1 count per 2.5 ms is equivalent to 1.17 m/s. So 2.5 ms is not suitable for deriving the car speed. 20 ms will give a lowest controllable speed of 15 cm/s. My plan to obtain a speed would be: 1. get the change in count every 2.5 ms and save it for at least 8 cycles. 2. sum up 8 consecutive readings every 2.5 ms to obtain speed as counts per 20 ms. I will use 1 integer to hold 8 samples. Recall that each sample's value would not exceed 15, so 4 bits is enough. Integer is 32 bits long  (stm32f103 is 32-bit MCU), so it can hold 8 samples. The r
閱讀完整內容