Adventures of a Tech, avonturen van een techneut

I got a second hand (but barely used) BF30 clone milling machine. The rpm meter was not working correctly (not showing high RPM, nonsense numbers) I investigated and found the photo interrupter on the spindle axle. It was covered in grease (sticky brown Chinese transport grease). After taking it apart I noticed all holes were over-sized (and slotted). Mounting the thing back and getting the perfect alignment would be a gamble (I like more precise work, but it appears all holes in this machine are too large or slotted, every edge is sharp and needs deburring). I made a little tool to check the workings, it is impossible to adjust once the motor is mounted so it has to be correct before I put the motor back on the machine. Here is the setup : The ring has 16 holes, so the rpm is more accurately (or quickly) determined. How this works : the system counts number of pulses in one second and from that displays the number of rpm ( NL: toerental in omwentelingen per minuut)...

A friend gave me a Denon DHT-T100 to look at. Do not spend much time on it.. ok. It had a problem, it started clicking and ticking after power on, and after some time. (a so called intermittent problem) Sometimes it did not tick or click, but it was basically not usable. The clicking had a sharp click in one channel and repeated after about a second, then sound recovered and it would click and drop out again. He told me, do not spend any time on it, yeah, right. ;-) like I would give up after 15 minutes. I wanted to know what was going on with this thing, I found some schematic online and started measuring the usual things. The power supply, 24V did it drop down when a tick occurred ? Difficult to find out because sometimes the thing would play for hours without a glitch. I eventually found out the 24 V PSU, the step down SMPS on board and the LDO's were all ok, all power rails remained within spec, but it still glitched sometimes. (while power was ok) I inves...

Yesterday I tested my new Chinese 2.2KW spindle with the VFD. After 10 seconds the whole place was smoking and I had to pull the cord. I took the VFD parameters from a blog, the writer appeared to be knowledgable, but man, it was a big fail. In this video I show how I set up a real low 3 phase voltage and Amp meter to verify the spindle. Enjoy.

I have made my new cortex M0 based microcontroller board operational with FreeRTOS. The chip is a W7500P - a cortex M0 with 16KB SRAM and 128KB Flash - hardware tcp/ip stack incl mac/phy on board (P101G) This chip is a single chip microcontroller/ethernet/internet IoT solution, no software TCP/IP stack that can fail or hacked. For TCP/IP buffers it has another 32KB SRAM, this can be used by 8 simultaneous TCP connections (sockets open at same time). I like this chip because it eliminates a lot of other stuff on the board. It is fast, and has lots of IO. I added a SD-card connector for data-logging applications. My main application will be small measurement and control applications, adding network easily and securely, super fast bootup times (0.1 sec instead of 20 sec, no linux based board with large bodies of software) ADC : 12bit, 8ch, 1Msps DMA 6-channel DMA controller Peripheral supported: UARTs, SPIs GPIO 34 I/Os  Debug mode Serial Wire Debug (SWD) Tim...

Yesterday and some days before I did some experiments in testing the LoRa radio modules I have from microchip. The modules were connected to some laptops over USB serial. I wrote some python scripts to send data using the pyserial library. One laptop was sitting on a table indoors, no real antenna, just a piece of wire. The other laptop was outdoors, walking around, no real antenna, just a piece of wire. The spreading factor for LoRa was SF12, power was set to high. Further details available on request. (email me) This experiment was very successful, about 1 kilometer, good connection, no loss of data. In the picture above, Richard is holding the laptop and the RF module, we are about a kilometer away from TX and get perfect data, on the overpass above the A2 road. But when we got between a lot of buildings, the results were not that good. At 700 meter we lost connection. 500 meter was mostly fine. In Tilburg an experiment was done.. and 500 meter urban was not...

Today the first LoRa modules arrived. I will be hooking these things up to a new board I am working on, it also contains a W7500P from wiznet (a cortex m0 with ethernet/IP/TCP stack inside) I Chose the complete LoRaWan implementation module from microchip to get started quickly. It communicates using a serial port using readable ASCII commands to the controlling MCU. Next step is making a break out board for this thing, it looks big but is only about 26.7 mm long and 3.3 mm thick. I will keep you updated. What is its use? It can communicate over RF (868 MHz) using LoRa protocol, using very little energy and over a very long range (10 km??) I am working on a easy to install sound-level and energy-monitoring/control system and think these modules can solve a piece of my very complex puzzle. It appears everyone in the world is jumping on the bandwagon right now to enable this IoT stuff, but real results and implementations are hard to find. If you need something like this, ...

Voor een bevriende ontwerper van waterattracties een proof of concept. Het betaat uit 2 pads van een AED, een chip met 2 oscillatoren, waarvan 1 beinvloed wordt door de pads. Op youtube fimpje gezet, 1 foto 1000 woorden, 1 filmpje ook zoiets. Dat scheelt weer veel typewerk. tot laters. Heb je zoiets nodig, neem contact op. Met gemak door 8 mm acryl isolatie, zal worden gebruikt met glasvezel/epoxy. Schakelt 1 contact, optisch gescheiden, voor bediening van klep of pomp in waterattractie.

In response op een discussie met een aantal "deskundigen" op het internet heb ik een filmpje gemaakt dat laat zien dat het gebruik van zenders, zelfs als zijn ze van laag vermogen, in voertuigen zoals auto's en vliegtuigen niet zonder risico is. Ik wordt altijd een beetje kwaad als ik mensen dingen hoor verkondigen met een zekerheid die grenst aan religeuze overtuiging en fanatisme over een onderwerp waar ze helemaal niks vanaf weten. Zo'n onderwerp is het effect van elektrische of magnetische velden op elektronische apparaten. Er zijn mensen (heel veel mensen) die beweren dat het gebruik van elektronische apparatuur en mobiele telefoons absoluut geen effect heeft op een auto of vliegtuig. De argumenten zijn dan : * "ik zet gewoon mijn telefoon aan, en we zijn niet neergestort" * "ze willen gewoon hun eigen telefoondiensten verkopen" * "die vliegtuigen hebben heel goede afscherming, dus dat maakt niks uit" * "Ik ken iema...

A few days ago I started playing with OnShape, an online design program. It can do a lot of things and I am very impressed by it. Check it out at https://www.onshape.com/ I designed a mounting bracket for my camera microscope (which needs to mount on my spindle motor) In 3D it looks like this  And after exporting the contour as a DXF file I milled it on my CNC machine. I used a 4 mm 2 flute end mill, at 20000 rpm. The mill had to stick out quite a lot, so I have some shatter markings on the surface, but it worked, milling 20 mm thick aluminium. The results are here. Impressive right ? Until next time, Greetings from Holland ;-)

Today I repaired my laptop. It was not working anymore, completely dead. Here is a link to the manufacturer : http://www.msiwhitebook.com/product_spec.asp?model=MS-1035 It is an old one, it does not support Virtualbox, but runs Debian just fine. I like it because it has a 17" screen, nice to work in bed, full size keyboard too. Searching for problems without any schematic is just gambling so I postponed it. I found a YouTube channel by Louis Rossmann who repairs laptops, https://www.youtube.com/channel/UCl2mFZoRqjw_ELax4Yisf6w and he got some schematics from a website : laptop-schematics.com I ordered my schematics for about 10 euro. I got 57 pages of PDF. I had to take apart the whole laptop to get near the actual hardware. I took my time, did not break any plastic tabs off.. And after what seemed like an hour I was where I needed to be. I started at the beginning, the power input and verified it. 19.14 volts. At the end of the ...

Today I repaired a parking sign. Why? Because I need to have an excuse to use my CNC milling machine, that is why! I drew the sign with Q-Cad professional ( http://www.ribbonsoft.com/shop/ ) and imported it into USBCNC. I used a 2 flute 4 millimeter end-mill and created a couple of P characters. Do you want to make one too : here is the DXF file , have fun.

Today I repaired a Samsung TV in just a few minutes. A friend walks in and says : My Samsung TV is ticking.. Red light blinking on/off... It is about 6 years old... What could it be? I just say : "Ah bad caps again?" Reply : "Do you really thinks so?" Let's fix this puppy a.s.a.p so you can watch TV again. So I take my screw driver and go with him to take a look at the TV. Indeed, it is trying to start but fails etc. tick tick tick blink blink blink... 1) remove power cord 2) take off back cover 3) look around 4) Notice caps with round caps in PSU??? Of course there are, 2 bad capacitors, 10 Volt 1000uF close to a thermal aluminium block. Alright, here they are... I say.. Exclamation : "Bad caps again? Can they not make anything anymore without bad capacitors, I bet most of these TV's get dumped in the trash for this" And that is probably true, a bad capacitor costing 20 cent will make your TV worthles...

Today I figured it out. What did you figure out, I hear you say... I finally resolved a problem with a USART on a STM32F407 board, that was easy to spot if I had just looked closely. I just lost a day in trying to find the fault. I am working with this board made by Olimex (https://www.olimex.com/Products/ARM/ST/STM32-E407/open-source-hardware) And connected it using ST-Link interface to my PC. I connected the SWD pins to the JTAG connector of the Olimex SWD-pin-1 ------ JTAG-pin-1 (VCC) SWD-pin-2 ------ JTAG-pin-9 (TCK) SWD-pin-3 ------ JTAG-pin-4,6,8 (GND) SWD-pin-4 ------ JTAG-pin-7 (TMS) SWD-pin-5 ------ JTAG-pin-15 (TRST) SWD-pin-6 ------ JTAG-pin-13 (TDO) I connected the serial port (USART6 is pins 3 and 4 of UEXT) of the Olimex to the TX/RX lines of the ST-link (see the green circle) Then I wrote a program and tested it. I made sure the PLL of the STM32F407 was running, configured all the needed files. defined the target cpu in stm32f4xx.h (...

Currently I am working on an alternative controller for AutoJet Technologies Spray controller made by Spray systems Inc. http://www.spray.com/spray_nozzles/pulsajet_nozzles.aspx I have been working on a more advanced and microprocessor controlled controller, it is intended to be used where the Model 1008 (AutoJet PWM driver modules, aka CP-PMDCT1008-XX) are not advanced enough or easy enough to install and set up. The 1008-AutoJet device is a pure analog box, it needs to be programmed with potentionmeter/trimmer inside the device and can be controlled externally using industry standard 0..20mA current loop to control frequency of pulses. The typical application I am looking at is the airless deposition of oils or emulsions used in the production of concrete products. The oils or emulsions are used as releasing agents with high viscosity, mould release agents designed for the production of expanded concrete blocks.  Deposition with air-driven nozzles leads to inaccu...