Raspberry Pi cooler

A fan design for the raspberry Pi (up to RPi 3B). it uses a very common 40x10mm fan with angle duct (I think its the same one used by Creality to cool the ender3 series).
I also made another version that really cools anything above the RPi3, including the RPi4, it uses a 5015s blower fan. it keeps the newer Pi’s very cool (no more than 20 above ambient under full load. )

RPI B fanL v10.f3d


Because we all do it (safety for tools)

ADAfruit makes some amazing little devices. One of them is the Circuit Playground.

I had this issue where I would do several projects at once, some involving the soldering iron, so i flip it on, do the job, and that’s it. notice what was left out of that sentence? yeah, sometimes i forget to turn it off. There have been several occasions where the iron was on overnight unattended. NO MORE.

I needed a temperature sensor,a micro controller, a speaker +amp, and LED’s to make a proper warning system that the soldering iron area is hot. guess what i used.

When the area above the iron reaches anything above 33° Celsius (almost 92 Fahrenheit), the circuit playground above the station switches to RED, and beeps a 1 KHz tone every 15 seconds. Every time it beeps, it takes a fresh measurement and resets that state.

When the temperature goes below 33°C, it goes back to its safe state, no beep, changes color to Green, and polls the temp about every second. it pulses a tiny LED on the board each time it is polled.
*One little warning, if you have a fan like the one pictured here (home made charcoal solder filter fan… for another post) and it is blowing on the iron, you may not get a good reading or warning. you can adjust the code if you need to.

I send the serial output to its connected COM port so you can do like i do, and monitor it yourself with the Arduino IDE, putty, or whatever you like to use.

with this info, you can read the simple code down below and see exactly what it is doing, and my hopes that anyone else that has ever left their iron on, uses my simple idea..

and YES, binder clips are what it being used to hold it, as you can see, it is perfect, so laugh, or improve it. I’d like to see other users do better, really. Send me an email or post a picture and let me know about it, ill include it here.

and here is the code i used to do this.

#include <Adafruit_CircuitPlayground.h>

float tempC, tempF;

void setup() {

void loop() { // use modified blink sketch for polling identifyer
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on
  delay(10);                       // wait 10ms
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off
  delay(10);                       // wait 10ms
  tempC = CircuitPlayground.temperature();
  tempF = CircuitPlayground.temperatureF();

  Serial.print("tempC: ");
  Serial.print("  tempF: ");
  if (tempC < 33) {
    for (int x = 0; x <= 9; x++) {
      CircuitPlayground.setPixelColor(x, 0,   tempC,   0); //(pixel#, RRR, GGG, BBB)
  else {
    for (int x = 0; x <= 9; x++) {
      CircuitPlayground.setPixelColor(x, tempF,   0,   0);
    CircuitPlayground.playTone(1000, 50);


my Amiga 1200 pt.3 (its back)

well, the fix was easy, finding the time to get measurements was not, but the repair took 3 min to do, after days of looking over pictures i took and schematics, along with this lovely online resource of a full traceable board-view. and some info from this page *of a A4000 audio repair guide.

The problem… a capacitor (C304) leaked on a trace that runs from the top to the bottom of the board, this trace goes from another capacitor’s +12v (C303) line to pin4 of the Op-Amp (U15) and would not power up the opamp with its proper voltage. in fact it was pushing that -12v from pin 11 and gave the opamp input a reading of ~-8v. not good. and im sure would cause issues if left unfixed. so, i jumped from the cap to pin 4 (large overkill yellow wire next to the scope probe) and it works like new. “a’Migamix is reborn”

The picture above is a reading from an output using a kit built DSO150 oscilloscope instead of my siglent scope (maybe more on that later) of one of the channels while i was playing one of my old DSS song modules. You can see the new CF harddrive in the picture too.
It’s fixed, it works great, but i noticed other damage around that area. i will be testing and cleaning up some thru-hole traces if needed some other day after i work on a few other key devices in my “ill get to it one day” pile that is quickly shrinking.

edit, whats next for my 1200, get an add-in card for the video out so i can connect to a modern monitor.

* broken link, will fix when new source is found


my Amiga 1200 pt.2

so, i will make this short . i “re-capped” my amiga 1200 (replace all electrolytic capacitors, not SM ceramic type). i am glad i did it since some of the caps were already leaking, and did do pad damage to the board. ( C821 was the worst one of them and had to rebuild a connection for the pad. )

first real time using a hot air station on something i wanted to keep, so i went crazy with the kapton tape. this was the reason for buying the hotair station and several other tools and parts.

I did not take video, and did not get many pictures after the project since i wanted to test if the re-capping fixed my sound issue. it did not. i am hoping the next part of the fix will do it. i will be ordering a replacement op-amp chip and hope that’s the issue as i would be very upset to find that the custom “paula” chip is the problem. anyone reading this , please cross your fingers. that post should contain some basic Oscope shots of the signals being generated by paula and the existing op-amp. there is sound, just an issue with the gain.

after the re-cap, i then ordered a IDE to CF adapter and took the very old mechanical hard drive out. installed the OS on it, and just dreamed about how computer tech would be so different today if the company back then were not so foolish. the new “hard drive” is now in use with the PCMCIA CF adapter i got several week before the recapping so i could pull files from their original floppies. still, right next to this REAL amiga, i have been setting up Ambien, a raspberry Pi emulator that will be put to use.

i also did a simple mod on an old PC floppy drive that allows it to be used on an Amiga, and will need to design a case mod for it to fit properly and be closed up or run as an external. the top of the case is not on it at the moment for this and the op-amp reason, im not done.

after my original 1200 gets up to snuff, and all mods are in place with the case closed, i will be looking at the A500 that was given to me with some genlock/toaster gear included with it.

my overall goal of getting the sound working is because i would like to use it with my music gear… project #2469


Its a Fake

Its not easy or even possible to find good quality or REAL IC chips on seller sites like Amazon, Ebay, or Alibaba.
if you want the real thing, you will have to go to sites like Digikey, Mouser. as they are the official distributors of Several chip manufacturers and will most likely not have a slew of fake chips for your final product or prototyping.

Let us start with something i discovered when looking over some chips i purchased from radio Shack, only months before the store near me went into liquidation (it was still an active store). the other night, i decided to look over all the different 555/556 chips i had in my storage.
before i go too much into what i found, have a look at this site, then see where i doubt that any of my chips are real. I would hope the ones i got from Adafruit are real, but i cant find any confirmation of what a real one looks like. the saddest part of it all, Radio Shack sold the .25c FAKE items for a markup that would make a fountain drink dispenser blush (service industry food cost joke).

labeled as 556 (dual 555) purchased from Radio Shack, the original chip has been scrubbed so this may not even be a timer or from TI.
another chip labeled as 555, also from Radio Shack, also scrubbed
same as above, purchased on the same day, from the same bin.

When you buy one of those 50pk 555 for 8$ from ebay/amazon/Shenzhen, you are NOT getting the real thing, they may kinda look legit, but no. some people have claimed these scrubbed chips are far from a 555, but in fact may be cheap op amps.

Left: 1 of the 50pk 555 chip — Right: Purchased from Adafruit and the closest thing i can find to being a real ne555p IC since supposedly they get their stock from official sources.

In short, im going to see if there is an easier way to get the word out about fake chips of any type, and it would be a good thing if Chip makers had more than this joke of a page. come on TI, bang the rocks together and let us help you get real devices to users.

this is sort of a rant post, more of a “we need to make it easier to get maker tools and supplies for those starting out, or those prototyping the next big thing noone can live without.” We also need to call out those sellers that sell fake chips, and make it harder for them waste your time.
and i dont mean by doing this…
FTDI on counterfeit chip bricking: “Our intentions were honorable”

As soon as i get time, i might make a 555 tester/stress’r and see how many survive or work to spec. In the mean time, have a look at some projects you can do with real 555’s


Full of hot air

my quick assessment of a “cheap” Yaugong hot air/rework station i received recently.
Looking all over the interwebs, you will find many “older” vids about the very common858D hot air station

I’m not going to discount those vids, maybe i got lucky and went with a different brand that appears to have some safety updates and fixes to issues i saw in many of those review posts/vids.

It looks like the issue fuse being attached to the neutral side of the 110vac line on US versions is fixed by having an all in one plug/fuse module. and the power cord itself is removable. i guess the hot-snot (glue) is there to keep the tabs from pinching in and getting pushed into the unit. :-/

It appears the device has better grounding than older versions and it checks out. checked ground pin, to chassi to nozzle to the plug that is in the back. the wires are still soldered and not crimped. the transformer seems a bit small for its use so it looks like a “bare minimum” rated trans, nothing more.

The controller board may be flashable but i wouldn’t know, this is one of those “binned” chips with zero markings as to what it is. (this is a major pet peeve of mine.) im only to assume it might be an atmega clone chip, but im not going to know until i dig up the schematics. (LMGTFY.com)

Its a common generic rework station that can be had for around 50$US and is just rebranded by loads of companies. this version has some safety improvements but i would say if you do the occasional hot air work, this is fine. If you are going to be using more than a few hours a day for a long duration, look at something that has better quality/safety checks like Hakko, Quick, or Weller.

UPDATE: soooo… I pulled the heat wand apart, and the grounding to the actual metal end was … well… sad, i found a small tab of metal soldered to the hot end, and a wire twisted around it. not the most reliable connections. never going to get a UL stamp.



just a quick idea

I’d like to start a sub page that gives lists of Bill Of Materials, or BOM’s for projects and lists of things like exact capacitors and other common repair parts for things like my Amiga 1200 restore project, or DIY kits and assembly without a crazy search through digikey or mouser. the list would have links to the parts, or category sections on those sites. I am actually planning on contacting electronic part outlets and other board assembly companies. this little bit is what is lacking in the electronics hobby/maker/learner realm

if you have actually read this and would like to contribute, or have ideas to get this going… contact me.

I think it would be fun, and a good learning tool for beginners.


my Amiga 1200 comes back to life

in my pile of not working but will one day, sat my Amiga 1200, between moving with it from New Orleans >Houston>New Orleans and it getting many hours of use, it stopped working.

first pin back in place, cooling, on to the next two. (pulled frame from microscope camera)

found two reason why, it was the accelerator card which dragged it from a blazing 14.### Mhz to a screaming 28.### Mhz (oh the raw power) and added a huge 8Megs of brutal fast memory. can you smell the sarcasm compared to today’s Ghz standards? The other reason was.. please dont laugh, i had a penny in the RTC battery slot. i have no idea why i thought that was a good things to do instead of buying a battery that fit. it worked like that for many years so i cant call it too silly of an idea.
the the 68030 chip had damaged pins, i dont know how that happened, and it must have been broken when removing the card at one point (maybe to put that penny in the battery holder) anyway. i carefully bent those pins back down to the pads (still intact) and carefully resoldered the 3 broken points. after putting the card back in, i booted up with the 80M harddrive i put into it years ago, and started my nostalga run.

all is not perfect, the sound barely works, and investigation points to the need to replace all of the old capacitors, so that project is now in its early stages and will be carried out AFTER i get ALL of my Amiga floppies to a modern medium since my 1200 never had TCP access. Im waiting on a kit that will use the PCMCIA card as a mass storage device so i can do a backup of everything. The internal floppy drives has issues, but im going to use the external on i have for as long as i can before opening the computer again. if the external fails, i have already done the “MOD” to to old PC floppy drives that should allow them to be dropped in if needed (untested).

Whats next? bit by bit, im going to get it back to its full glory, even if i just put it on a pedestal running old demo’s. im going to get it upgraded as far as i can with CF hard drive replacement, new kickstart, new workbench, scandoubler, and working sound so i could hook it up to my music gear and use it as an extra piece of music gear

in the meantime while waiting for parts to arrive, im also running a PC based emulator with the exact configuration and accelerator card as my real thing that can be loaded from my home file server. i will be making a raspberry pi version to hopefully replace the need to run the hardware (glass case pedestal time) and cram it into a mockup of the Amiga 1200 power “brick”.

an acquaintance of mine gave me an Amiga 500 and loads of amiga video editing gear and software. i haven’t even powered it on and have no idea if any of it works. i dont know what i will do with it. maybe try to upgrade it and use it… one day.


Jump into 3D

After my post in may, i purchased my first 3D printer, a prusa Mk3. This was after seeing many electronic “maker” posts and using machines to make models, cases, and prototypes. Of course i wanted to do all of this too. so i jumped head first into it, knowing nothing about the 3D printing. still i was being called a very knowledgeable person in the field only 2 months after getting this printer. see, when i want to learn something, i go all in. i learned how to debug issues in the printer, figure out why a print was not as expected, and about the different materials. 3D modeling was something i said to myself, “eh, im a very good drafter, how hard could it be”, in may ways, i was right. my Drafting knowledge and ability to visualize CAD models helped me. so, i took on several 3D packages.
Fusion 360 (free(ish)) – Excels in modeling prototype objects. i use this most of the time
FreeCAD – still in beta, but will do almost everything fusion360 can, its just more clicking and setting values, not much in the way F360 works where there is an arrow you can pull to place/size an object, you have to type in the dimensions and placement. it may be more difficult, but im finding it enjoyable to use. im still learning it how to work with it.
MeshMixer – mostly used by me to repair models, or reduce mesh model triangles (the triangles are what make up most 3D models.)
Blender – best used for making organic models such as figures and sculpting objects. it seems to focus more on being a 3D animation studio so its not something i will use or explain most of the time.
i will be trying several versions of AutoCAD soo, to see how well it works for 3D, i hope it is as easy do use in 3D as it is for me with 2D and ISO modeling.

while 3D printing is starting to take off (or i have put myself in that bubble and assume something that’s not accurate), there are many things that stand out about getting the devices to work and output as expected.
my Prusa works great, at times it didn’t, something as small as a 2mm grub screw coming loose on a main gear prevented pushing the printing material into the extruder (the part that heats the plastic filament and pushes it out of a nozzle onto the printing surface) and so ….nothing prints. this is not because this is a sub $1000 printer, its because its still new phase of the tech, and many places are working to improve the designs (while other companies just use and rarely innovate/contribute anything or go as far to make an improvement, and lock it up behind a overly broad patent they will licence out for amounts that would break the makers and lerners *breathes*). there is still a ways to go before “every household” will have a 3D printer in the corner of their room to make a replacement gear for their dryer. as it stands, this is still a tinker toy, its for those willing to get their hands dirty with a tool that needs care and attention sometimes.
its funny, when i show or say i model things for 3D printing, the first question i get is ” oh, have you printed a gun”, and i have to go explain to them how thats not how or why people do 3D printing. anyway, im going to be doing little tutorials on 3D printing, its good, and bad. problems/solutions.
and im about to go into CNC machines too.

i have a thingiverse.com account, and it has some of the things i have made, there are several other things im working on that have not been uploaded or are just not done yet, have a poke around.

for some tutorials about all of my projects, im debating on making a youtube channel or something like that. but if its anything like my updating of this site …
dont worry, soon i will be posting tutorial stuff, playing catch-up right now, giving my opinion and input. will add a few back tutorials on problems i had to fix.
im currently going through all my old “fix it one day” stuff and fixing or trashing. if i fix it there may be a tutorial. if i trash it, i may post something about its life.


And…Roland Roland Roland.

no pad at all, no connection,

On the front page of this website is an “artistically” blurry shot of my Roland Fantom S, the main workhorse of my music gear in the early 2000’s as it had a sequencer built in. well… it was down for many years because of a corrosion issue on the “edit” button, caused by a cat sitting on it, and hacking up a hairball onto the keyboard. i assumed i cleaned it up good, but apparently not under that important button internally (i just wont use stock sounds and effects and that meant i wouldn’t use the keyboard). i tried to replace the button with one on hand but for some reason i put it in and failed to look closer at the actual board damage. not so much failed, i didn’t have the tools to see it.

jumper to nearest pad

few more years down the road, i have the tools, and more knowledge. i decided to make one last attempt after i had successfully made micro repairs to a laptop board (.005mm). after digging the main board out and looking at it under my microscope, i found, there was NO pad connecting the switch to the board… well… damn. made a little jumper from the switch pad to the nearest trace, and the new switch works better than the remaining stock switches.

all the stuff i had to move to get to the main board. (not pictured because its on my workbench)

in a few more posts, anyone reading this may see how i gained more hands on knowledge, and in the past two years, i would say i have learned more by spending a few dollars on components, and some gear (even the super cheap stuff).

I know, i can do this all in one post, but i may touch on a topic that has nothing to do with fixing a keyboard. i may be giving views and pointers on Arduino and raspberry pi, 3D printing, building props, silly “no point but looks cool” objects.

i may add analytics and something on the website to let me know if i’m wasting my time but i have no desire to load your system with trackers from facebook and the like. its going to be used to see if the site has been visited at all.

well. its simple, i start updating this page but find im doing alot of things, then forget to document them because i’m on to the next project. my next few posts will be making up for that, im trying again. How hard can it be to type a few words? not hard at all if i could find the time.