ESP32 with OLED and maybe LoRa

I've bought a few too many ESP8266 boards over the years. Done a couple projects but most are sitting looking lonely in a box of good intentions. So in order to fix the wrong, I've decided I'm going to buy too many ESP32 boards.

I have a few of these:

• ESP32
• 0.96" OLED SSD1306
• About $8

And a couple of these:

• ESP32
• 0.96" OLED SSD1306
• 18650 Battery Holder
• About $10

And seriously considering these:

• ESP32
• 0.96" OLED SSD1306
• LoRa SX1278
• About 2 for $27

And want a couple of these:

• ESP32
• GPS NEO-6M
• LoRa SX1278
• 18650 Battery Holder
• About $26

Sanyo DP26648 White Screen of Death

 Santa brought my game player son a Sanyo SP2664 26-inch Widescreen LCD HD Television last Christmas.  A few months into the year, the TV started getting occasional white lines diagonally across the screen, the greens looked weird, and then the audio went in/out.  I could've/should've hauled it back to Wally Mart but grumbled about it and did nothing.

We came home from our July 4th vacation and the darn TV is dead.  White Screen of death.  No sound, just a stupid looking white screen.

An interesting thread on the Electronics Repair Google Group led my son and I to think that we could fix this beast.

According to the thread, "it has been reported that there is a defective ribbon cable that causes this problem".  And the possible fix is "Clean glue like material from spaced further apart trace of FFC ribbon or replace the ribbon wire P/N: N6CD FFC".

Well, I'm pleased to report that we hacked and smashed and tore that darn TV up, finally got to the elusive cable.  And it looks nothing like that picture.  Our cable looked fine, no glue, seemed like a good connection.  And the TV remains broken and in 300-bazillion parts.

We had fun exploring the TV but it would have been a better story if the darn thing would have actually been easy to fix.  I think our TV had more wrong with it than just the cable.  But if your TV is showing the white screen of death, read the link and good luck.

LG Washer LE Error

UPDATE:  I've had quite a few hits on this posting and received lots of great comments - thanks very much.

This post explains how to replace the hall sensor on your LG washer.  Before you decide that you have to replace your hall sensor, please try unplugging your washer for 5-10 minutes and see if it will reset all on its own.

Also, even after replacing the sensor, sometimes these washers will display "LE" a week or month later and they just need a time-out (unplugged).  Good luck!

I've also had a few questions on what the heck is a hall sensor. Here's a whitepaper with a good description, design notes and ideas on what else you can do with these things.

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We had a really nice Maytag washer and dryer set. They were a billion years old (maybe 15 actually) but ran strong and had zero problems. Spring 2007 we decided to remodel our laundry room and of course we had to have the super duper LG WM2075CW 27" Front-Load Washer with 3.72 cu. ft. Capacity, 7 Cycles, 6 Options, SenseClean and 8 Hours Delay Wash.

About $800 delivered. Nothing but the best for my socks and undies (boxers btw).

Everything has been great except the week before Christmas 2009, Mr LG wouldn't work. It would grunt and click and then put "LE" on the display. A quick Google yields lots and lots and lots of hits with the Load Error (LE).

A number of things can cause an LE but the most common is a malfunctioning Hall Sensor. Seems that LG washers are pieces of crap and this is a well known problem. LG has extended the warranty on the part to 7 years but they won't ship the in-warranty part to consumers. They'll only ship to a certified service company. After several phone calls to LG and way too many minutes on hold, I finally just ordered the damn thing from MCM Electronics, part number 6501KW2002A for $18. Plus tax and shipping, at my door for $29.75.

Actually the LG washer and dryer have been great, I'm just very ticked that LG has a known problem but won't do a recall to fix the part with a more reliable piece. And even more ticked that they won't ship me an in-warranty part so I can do it myself. So for now on, I will refer to the washer as a piece of crap and LG as a seller of crap. My next washer will be a Bosch.


The Google hit that explained the error, the part number and how to replace is FixYa. Their how-to was a little brief and a picture is worth a thousand so I thought I would help out the next sucker that also has a piece of crap that needs to be fixed.

Read thru that FixYa article and make a decision if your problem is also the Hall Sensor. If so, follow along.

This is a pretty simple fix. If you can change a sparkplug than you can easily do this one. (I compared this to a sparkplug change cause you'll get a little dirty, gotta pull some cables, and work a socket wrench).

You'll need a phillips head screw driver, 17mm and 10mm sockets or wrenches.

A quick note:  Even though the pictures are somehow dated 1/7/2006, they were actually taken in December 2009.  Someone reset my camera date and I didn't notice until pics were all taken.

Ok, First step, UNPLUG the washer. And carefully move the washer so that you can access the back panel. If your washer and dryer are stacked, please be careful and make sure there is nothing on top that will fall and hit you in the head. Ask someone to help you, don't blame me if you hurt your self moving the thing. Be careful!

• Remove the 4 phillips head screws on the back panel

• With a 17mm socket, remove the bolt that holds on the motor rotor. Turn the bolt to the left (counter clockwise) to remove. The drum will probably turn as you're trying to get the bolt loose so with your free hand, grab the rotor around 10 o'clock and hold tight while you turn the bolt. Be patient and it'll come right out.
  

• Next,you need to pull the motor rotor off to expose the stator. This will be a little tough because of the magnets and a tight fit. Use both hands on opposite sides and gently tug one side, then the other, then both. Try your hands at 1 o'clock and 7 o'clock. Then switch to 5 and 11. Be patient and tug gently. Watch the white center and you'll see it slowly pull away from the shaft.
  

• Set the rotor to the side and remove the 10mm bolts holding the stator on. I wasn't sure what to expect when I started removing it and I wanted to make sure I put it on right side up so I made pencil marks to line things back up. These really aren't needed cause it'll be obvious as to which side is up.
  

• When you remove the 6th bolt, use your free hand to hold on to the stator cause it will fall right off. There are two connectors at the bottom, one the goes to the motor windings, the other to the hall sensor that we're replacing. If you don't hold onto the stator, you might damage the wires or connectors. Go slow on the last bolt and hang on.
  

• Here's what those connector look like from the bottom side. I didn't have any luck trying to get them free from the bottom though. I was kinda squeezed in between the wall and washer so I didn't have much room to wiggle. I let the stator lean towards me like the picture above and then gently pulled both connectors free. Don't go Rambo on these connectors, you don't need to replace extra stuff. Breathe deep and squeeze the little tabs, they'll come free.

• Almost there. That shiny looking thing on the bottom right of the stator ring is the hall sensor. It's held on with 3 clips on the back side, 1 clip on the front. Simple pry up the 1 clip and it will pop free.
  

• The new sensor snaps back on just like you'd expect. Hook up the 3 clips first and then snap it on to the 1 clip side.
• I don't have pictures of these next steps cause it's just the opposite of the above. Just look at the pictures in the reverse order and it'll all go right back together.
  
• Hook up the two connectors. Make sure they click all the way back on.
• Line the stator back up with the bolt holes and screw the bolts back in with a 10mm socket. Tighten them firm but don't over do it.
  
• Push the rotor back onto the shaft. Because of the magnets and the shaft grooves, it will feel like it's not going. It will, line it up and apply pressure at the edges.
• Tighten the big bolt with a 17mm socket. As it tightens, the drum will start to rotate. Grab the edge with your free hand and tighten firmly.
• Put the back panel back onand tighten down the 4 phillips head screws.
• Plug the washer back in and carefully push the washer back into place.
• Test.
• Your piece of crap washer is fixed.
  

Total time was 38 minutes. If I didn't stop and take pictures, easily under 30 minutes.

What do you think? Leave a comment, buy me a beer!

Seven-Segment Vacuum Fluorescent Display (VFD)

Do you ever go to surplus electronic stores just to wander the aisles? Years back, I used to go to Skycraft Electronics in Winter Park. It's still there. On pilgrimages back to the homeland, I occasionally will stop by but it's not the same. Back then I'd go alone or with a fellow geek and be able to spend hours digging around. Now days I have a wife and/or kids in tow that have zero patience and it's rush rush rush. It seems that the beach, Disney, or Universal is more important to them than junk heaven. They need priority adjustments.

My current area had a junkier place called Misener Electronics, formerly Pembleton Electronics, that has potential but they keep moving locations and they may be gone for good. Current rumour is that they moved from the Volleyball Courts to 500 Coombs Street. No one answers the phone and I drove by the empty looking building today. I think we've lost the only electronic junk store in town.

When Misener was open last year, I found a box of an interesting FIP (Fluorescent Indicator Panel or Vacuum Fluorescent Display (VFD)) for about 25¢ each. I grabbed a handful and added to my junk pile. These look pretty nice but what can I do with 'em? Any idea how to drive them? I started Googling the part number and few a limited number of hits. Part number NEC FIP6C15A at least reveals these specs but doesn't give any pinouts.

NEC Electronics FIP6C15A Seven-Segment Vacuum Fluorescent Display - 7-Segment Numeric Package Style (Basic)=SIP Color=Blue-Green Number of Digits=6 Character Height (mm)=15 Vsup Nom.(V) Supply Voltage=3.7 Iseg (A) Segment Forward Cur.=150m Lv Typ.(fL) Luminance=700 Package=SIP

BTW, I also found a nice description of VFDs at http://hem.passagen.se/communication/vfd.html which is where I grabbed that image of the "Expoded" (sp) VFD. Seems that a common source of VFDs is old VCR displays.

Using the ATX PSU that I put in test mode, I applied +3.3VDC across the filaments (on this VFD, the two out side pins that I labeled as Element for some dumb reason), and then randomly picked a grid (which is one of the leads not below one of the yellow blocks on the back) and stuck +12VDC on it. Then applied +12VDC to various segments which are the pins below the yellow blocks.

The result was that many segments lit depending on the combination of the grid a segment(s) I had powered. Pretty cool. I called over to my son Will who then made it his life's work to light as many segments as possible. During his investigation, he shorted a segment to the filament and we got a nice spark show and the PSU shutdown. I was worried that we blew out the VFD but after a brief power cycle, the fun returned.

This was pretty cool but obvious that it would be tough to control this with an Arduino to make it a useful display. A Maxim's Application Note 1154 lists VFD Tube Manufacturers' Web Sites. In that appnote is a list of Maxim tube driver chips that would be great for interfacing to my VFD. The MAX6934 looks about right.

Of course after tiring with the NEC VFD, we then had to rip a more complex one out of an abandoned VCR in the garage. This one (no pictures) was odd. After hooking up the filaments to +3.3VDC, any other pin that we put +12VDC on caused stuff to light. On the NEC FIP6C15A VFD, the grid had to be powered separately, then segments were lit by putting power to pins. This VCR VFD seemed skip the grid power need. ?? Doesn't seem right but that's what it was doing.

PC Power Supply for the Lab Bench

Seems like everyone has converted an old PC Power Supply for use in the lab. I've been using old wall warts for most of what I need so I haven't really paid much attention to the weekly instructable or hack that gives the step-by-steps. I admit, it sounds great. Plug in the supply and you have instant regulated +3.3VDC, +5VDC, +12VDC, -12VDC, -5VDC, and +5VSB. Yup, sounds great.

Wait. +5VSB, what's that? It's the 5 Volt Standby voltage. It's the voltage that remains running when the power supply suspends and is used to power the "wake on" devices such as network cards and modems used to bring the computers out of suspend mode. It's been around on PSUs for quite some time, I guess just haven't noticed it.

Since the wall warts are ok for me, why am I writing about a PSU? Because Spoofee told me about a dirt cheap one. Buy it, rebate, and it's almost free! I love almost free 'cause it's really cheap. Okay, I did the buy and rebate thing and now have a PSU sitting on the bench. I guess the instructables are needed.


But first a warning. All I'm doing here is simply putting the PSU into a test mode so I can vampire the juice from a connector. Although the volts are regulated, the current can zap the crap out of your circuit if you short something. Check out the instructable above to see how you can do this better. Read the comments to that instructable to see the many cons on using a PSU for your project. I'm lazy and just want quick power to run a VFD that I'll blog about soon. You, are not lazy and will do this better. If you do this to a PSU, be careful.

Here's a real decent pin-out that I found at Help With PCs. I especially like the color coding 'cause it helps my old eye find the right volt pin quickly.

The Ultra X-Connect PSU that I have has a ATX 2-pin, 6-pin Xeon, 4-pin Pentium 4, and five 4-pin Molex connectors.

A problem with ATX PSUs, they won't power up without the Main Power connector being hooked up. To power up an ATX or ATX-2 PSU for testing, short pin 14 (PS_ON) with one of the grounds.

I just stuck a wire in the 20-pin main power connector and shorted pin 14 (PS_ON) to pin 15 (GND). Just like that pic over on the right.

The PSU rumbled to a start and viola, free power. VFD, here I come.

Wide Screen HDTV Surgery

Our Sony 46" Rear Projection HDTV had a good life. We bought her new in 2003 and had only minor problems. A few months back, she suffered convergence issues that I just didn't want to pay to have fixed. It was a good excuse to look for an LCD wide screen. So the old Sony was banished to the garage to make room for the new Sony Bravia.

With the convergence problems, I couldn't sell the TV except for parts so what to do with it? Crack it open and see what can be salvaged, of course!

After carefully removing 753 (or so) screws, the rear panel, speaker grille, front panel (beznet) and mirror cover pop right off. The first interesting thing I found was 4 sensors around the perimeter of the beznet. These are pointing in, away from the front. It took me a second to realize the coolness of this design. Your average couch potato points the remote at the screen. The IR goes thru the screen, bounces off the mirror, and gets picked up by one or more of the perimeter "bounce-back" sensors. This, in effect, makes a 46" IR sensor. Very cool.

As I stared at all the various boards and wire harnesses, I figured a Service Manual might come in handy. After much Googling, I located a manual at:
forum.electromaniacs.com - Downloads - Service Manuals - Sony - SONY RA6 CHASSIS KP46WT500 PROJECT

I posted a thread on Make Magazine's blog to see if anyone had ideas on tasty parts to take and/or suggestions to do with this thing. The best response was actually what I expected. Maybe some good wires, connectors, and capacitors. But basically boring.

Other than the IR sensors I mentioned above, I haven't seen any cool things. The bulbs were disappointing as they are actually CRTs which don't appear to have any obvious secondary use. The speakers are a keeper as well as the magnifying screen. When the weather cooperates, I'll go back to the garage and see what else has promise.