Please feel free to explore my YouTube channel for even more videos. Most of the ones I have uploaded do not include any speech/explanation, however do not hesitate to go-on and write me a message.
If you need more details e.g. documentation, circuits, firmware or general guidelines please feel free to contact me here.
Some trials to create a wireless connection via the FM radio band (88-108). It was partly successful in the end after adding a schmitt trigger after the receiver, however this hilarious footage shows me, trying to make a connection by feeding-in the chinese ratio receiver's speaker output directly to the microcontroller's port (first thing to try when you only have all that garbage around you). The string sent is "Krastavica" ACSII, in Bulgarian meaning a cucumber. So, I guess there could be some gurus out there, who will be able to decode that "noise".
You can briefly read more about the project we did here. I am just listing a show-off video of the simple system we had.
During my first year at university, me, Tsvetomir, Simon and Kamen decided to give a new life to an old mechanized robotic hand produced in the late 1980s in the Factory for Medical Equipment in Sofia. The six stepper motors were originally controlled by one of the first Bulgarian 8 and 16bit computers - Pravetz.
However as these were obsolete, we decided (most credit goes to Simon) to create a new stepper motor control module with an ATMega32 instead. Here's a show-off video. There was however an issue with the mechanics, as the steel cables were not correctly threaded and thus the "robot" looks like disabled.
You can read more about our automatic weather station project here. However, as I will be listing videos on that page, here are some too:
An overview of the initial "fly-around" prototype:
A somewhat more completed prototype on a separate PCB - first tests:
First tests on the pole (not mounted at full height):
Another view, now mounted and tensioning cables attached - height 11 meters.And in case you want to see what the weather is in Ruse now: http://220.127.116.11/
Here's an update on the powder filling machine prototype I was trying to develop. It is quite intuitive, I was trying to use a screw conveyor, German/Bulgarian: "Schnecke/Шнек", as a filling mechanism. The idea was to have a strain gauge measuring the amount of material falling into the package and actively controlling by PWM the DC motor's speed. I was using an "el cheapo" resistive tensometric strain gauge (a wheatstone bridge kind-of) feeding it directly to an AD620 instrumentation amplifier. The amplified analog voltage was fed-in to the PIC's ADC and was oversampled to get some more stable readout (too noisy/fluctuating otherwise). A simple linear control algorithm changes the PWM accordingly, until a desired weight (AD-in amplitude is reached).
Surprisingly it was accurate up-to plus-minus 5 grams, for a set weight of 50 grams, offset and gain calibrated in advance. The aim of achieving plus-minus 1 gram was too optimistic, as the whole mechanical system was very crude. Possibly a lower-step screw would have somewhat improved the whole system.
In 2010 I had a task to find way to control a two-pole DC motor quickly enough. The whole control module (to be developed) was supposed to be used in the dosage apparatus of an automatic packing machine (to be developed) and provide an active feedback for the dosage system. One of the above videos shows an example of the test dosage prototype. This video below practically shows a PIC MCU, controlling the DC motor using a 1 kHz PWM. Nothing special/very intersting, however it may suit as an inspirational video to newcoming electronics hobbysts.
I'll leave out any comments here :)
I guess you've never thought that it is possible. Dekatron counting tubes are basing on a somewhat similar principle. Ronald's electronic project site is explaining the principle very thoroughly.
Nothing special here, besides the joy and fun such a simple circuit can give you.