By request for an irrigation system based on “Ebb and Flood irrigation technique” I made a system that should be able to handle a very large area and variation in complexity as well as irrigation types. The system is modular and is based on a main unit and multiple modules that are used for sensors and system control. My idea was to make the system stand alone so there should be no need for a computer running the garden/greenhouse, but I still wanted a good and easy way to configure and log the system. So with that in mind I built a system that is stand alone, but configured with a PC program trough radio/USB.
This is what I came up with:
While I worked on my own segway I got a request from my University (KTH) to create a vehicle that the students should be able to test their control system theories on. So I created an improved version based on my own segway.
I made a system for signal data acquisition that had to be modular and also work standalone without a connected PC. It should be powered by battery or usb and communication should be done by Bluetooth or USB. The memory had to be absurdly large or else I had to implement a trigger and sample profile that should be able to handle various situations. The later was the better solution. I did the PCB HW and firmware plus demo PC software that held all the functions/classes needed for another guy that did the final PC software, mechanic parts and HW installation.
So, what to say. I can’t just build and fly quadcopters. As usual I have to create something that makes me gain knowledge or create almost the same solution but based on my idea how it should work. So I couldn’t really help my self when I did not really understand why one ESC-Motor-Propp setup would be better than an almost similar setup. And there is a lot of information “as usual” on the Internet, but most is based on the writers opinion.
So I figured the best thing is to build a solution that really tests all of these parameters at once, so I can get my hands on real data to analyze 🙂
So the previous quad with big motors and battery became a bit heavier then I hoped for.
So I made a smaller hex one with my standard frame solution.
And this one is running on 2s 🙂
I do not know how long it will hold because the motors are burning up on 2s, but wow the quad packs some serious punch 🙂
So I made a new quad with my Raze32 FC board. One with FPV 8x20mm motors and a sleek carbon frame.
Read MoreSo I been trying to build as small quadcopters as possible for a while now.
So I tought that the next step would be to design my own FC med integrated brushed motor drivers for a hex quad.
Been using the micro multiwii for some time, but after I started using the Naze32 for my 250 quad I was really looking for a better version of the micro multiwii, with no luck.
So after some time and searching I did my own version that is HW compatible with Naze32
I just finished the cad, and will be ordering a few boards tomorrow, will be fun.
I named it Raze32
It has the same HW as the Naze32 without the PWM7 and PWM8.
But I have added 6x 7,5Amp motor drivers for DC motors. the board can be assembled with or without the DC motor driver. So I can make a real hex micro, and still use the board for my bigger quads
Other then that there is a SBUS inverter that is connected to CH4 on the board.
2 open drain 300mA ports, so I can control leds direct.
the board is only 20x38mm and 0,8mm thick.
The motor driver takes 9mm of the lower part of the board, so it could be 20x29mm without the motor drivers.
the board has 3 voltage regulators, one extra for the external radio RX.
The MCU and MPU-6050 will be tested with 3v and 2.8v regulators, to see if it works Okay with lower voltage.
So there should be no problem with low voltage drop on from the battery if I use 1S.
It is designed to take 10v, so I can test 2S on the micro copter projects
The side pads is designed for standard 2.54mm pin headers.
Really looking forward to test them out
Read MoreSo my own design did not survive a 20m fall from a tree, how shocking 🙂
So I bought
a BEE245 from birdseye, a bit harder to break I hope 🙂
Read MoreI am currently teaching a PCB Design course at my University (KTH). And the two previews years the students had to build a STM32 prototype board. The problem was that many of the students thought it was really hard to design the board layout, and there was not many that used the board afterwards. So for this year I changed the design so they should create a lab power supply. If you are going to study electronics you got to have a lab power supply. So I put forth three different solutions that the students could choice from, easy, hard, harder 🙂 . Easy is only a board with internal voltage reference and two potentiometers for voltage and current. And the two other has a STM32F3 Discovery board as a reference and controller, with the harder boards the user can set the voltage and current limit trough push buttons.
Specification of the “Harder” board.
This way it is better, because now I have a better way to determent (and show) how good the student has designed the board. By noise measurement with static / oscillating load or no load the students will see how good their design is. And I suspect some boards will oscillate or in worst case burn. So the students will be faced with troubleshooting their own board. And if the student board works, I will introduce a fault so they have to troubleshot, which is the best way to see if they understand the inner workings of the design 🙂
Read MoreI created a intelligent LED driver for my friend Marcus, his current project is to build a underwater torch light. The controller regulates the current to the led based on intensity setting and LED temperature. Most underwater torches are easy to break if you use it on land where the LED/Lamp will get overheated pretty quick. The controller can supply the led with 1.5Amp at most, I believe he is using the CREE MKR which is rated to 1665 lm at 15.25 W (12.2 V, 1250 mA). The first idea was to use the MCU to sense the voltage over the led when it’s turned off, and then use a PC screen to send command to the torch controller trough a PC program -> Screen -> LED -> MCU. But when we tested the idea it showed us that a standard LCD Screen did not affect the voltage out from the LED. but if we used a normal lamp or sunlight the LED supplied a few hundred mV, so that idea did not work. The board holds two switch regulators, one for the LED and one for the MCU. And the MCU can
also read the LED current.
The MCU is a STM32L151
Want to read more about Marcus underwater torch, click the link LINK
Read More