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Sixth Sense Design Challenge

16 Posts authored by: weiwei2
weiwei2

Finisher prize

Posted by weiwei2 May 7, 2019
I have received my finisher prize today. Thanks element4   The interesting is that it is programmable. It is the first programmer quad copter I have ...
Really did a last minute rush to complete it, although very much scaled down in term of operation from what i originally envision The bot with power bank to power up the Nucleo, load cell and Hx711 based board that utilize the load cell FX1901 the board is SEN0160 load cell FX1901 is mount in front of the scissor to sense any grass (hitting a big enough weed will give a reading to load cell) The load cell is glued to an ice cream stick to extend it all the way up to the end. And a shampo ...
The sensortile website at https://www.st.com/content/st_com/en/campaigns/sensortile-edu.html  provides wealth of information though somewhat confusing (e.g in the curriculum tutorial suddently it has Linux based beaglebone)   Anyhow, we follow the tutorial Note: out of box, the SensorTile is using https://www.st.com/en/embedded-software/fp-sns-allmems1.html , so we want to revert to it out of box state, that enable the SensorTile to be connected to phone, we should revert to using t ...
My previous blog is kinda long, so i put the motor control outcome in this blog instead   after verifying that the nucleo bot is producing PWM and DIR signal, i test it on the robot. The nucleo is powered up with the always on powerbank, whereas the bot is powered up with NiMH battery   It is moving but not to my expectation. I have being expecting both the left and right motor to be turned on at the same time   explanation to be continued..... ...
MBED maintains all the supported board programming reference at https://os.mbed.com/platforms/   For our board, F411RE, it can be referred at https://os.mbed.com/platforms/st-nucleo-f411RE/ i copy some of the essence here Converting from Arduino The Nucleo-F411RE has arduino compatible pinout. However, to use some of library created orginally for Arduino, we need to do some conversion from the arduino code to MBED. When naming the pin, it is best to use the pin name under "MCU pin ...
NOTE: i actually forgotten about this #9 blog so only post it today, few weeks after i initially work on it my blog 12 is the coding sequel to this   Introduction There are multiple IDEs that can be used with the Nucleo-64 STM32F411   Today, i try with the MBED. It is cloud based and free. After logging in to your developer console, one need to select the supported board. I add the STM32F411 and choose to create a new hello world example....in this case the LED blinking. Screensho ...
Due to really lack of time, rush out this simple motorized scissor first, i cut out a L shaped holder from old table calendar cardboard. it is hard enough and easier to work with After that, i glue the scissor to the L-shape holder. well i could have attached it with screw, but...to save time, glue is useful And this is the video that it is in operation. i do find that it needs at least 5V to operate properly. At 3V, it cannot move From the power supply, we can also see that it needs 0.3 ...
time flies, and soon it is deadline for contest. today i am assembling the 'weapon' of the robot, the motorized scissor. First, i want to choose a suitable motor to drive the scissor i dig from my collection and found this Tamiya motor set, and assemble it with 4:1 ratio Then we do a simple test with power supply, driving both motor at 3V (low enough so that i can directly drive it from the Nucleo 64 later http://vt.tiktok.com/JF5WPP/  << the link of the motor testing   & ...
As i was testing nucleo64 in mbed notice that some arduino pin convention needs to be changed for example, the pinMode in arduino need to be updated pinMode(_pin1, OUTPUT)  ---> reconfigured as DigitalOut i am wondering if there is any tutorial documentation that shows how to do conversion to MBED, listing every compatible command in arduino ide to what we have in MBED   Nonetheless, few days ago i tested with a MCU that uses the arduino IDE instead. Each of motor driver can be dri ...
Following yesterday blog, i have left my battery charging overnight. Today, when i measure its voltage with my Sanwa CD800a it reads 8.4V, surprisingly higher than my expectation.   So i bring it out for testing on the grass and it runs   Next step is how to connect the nucleo64 board to this 13A motor driver board. ...
Following from yesterday post, today i try to connect my bench top power supply to the 13A motor driver to test it   i first tested with a single motor, then i realize that i can just chain two motor together. The objective is just to test these   1) test setup: 1 motor, 12V i am astonished to find though my motor is rated 12V, the original chasis only use 7.2V to drive it. i don't see that there is a DC-DC converter is used to boost the voltage up to 12V either this is a simple no ...
wow, time flies, i realize i haven't posted anything for 1 months plus. This post is a relatively short post   i was out for oversea trip for 2 weeks, also another 1 week for Chinese New Year holidays, nonetheless over the last one month, i have look at trying to build my motor driver circuit with MOSFET i got some IPT60R028G7 infineon COOLMOS high current MOSFET, which is capable of 75A continuous drain current and an optocoupler TLP521-4   i then research on some home DIY PCB maki ...
Reality struck. despite its 'formidable' looking track, my chasis cannot move properly on the grass. The video shows that it struggle to move on my garden grass. The motor driver is a ST L298 based motor driver. It is dual channel but limited to 2A per channel. As one can see on the video, my power supply is also running into the >2A range and sometimes overload.   One way to solve this is to make use of current capable motor driver. I am right now evaluating the option. i do want to ...
I use a tracked chassis platform, which i ordered from Shenzen and it has arrived yesterday. Getting this shipped has gone through some drama. At first, the shipment is rejected by by forwarder, as it contains LiPo battery. I got to cancel the shipment, communicate with the seller to buy another set without the battery. In total, it take less than 2 weeks to ship, which is a very decent speed. As the chassis is not the main "sixth sense" design in this work, i have decided to use an off the shel ...
weiwei2

The Motors

Posted by weiwei2 Dec 24, 2018
I have just got a UPS update that my kit will reach on 26 Dec 18, right after Christmas. So i still can enjoy the Christmas holiday now. Anyway, the only update i have is i have decided to go for somewhat fail safe chain track chasis. It does comes with 2x of gear motor (DC 6V-12V with 320mA no load current, 446rpm, 4.5A stall current). Well, these pair of motor should work on my playground. If they don't i have another pair of 6W Maxon DC geared motor which i salvage from an old factory automat ...