Electronics – Foxes Den

Meshtastic

Ever heard of the Meshtastic decentralised off grid communication network? You have now. Dive in and get involved.

What’s that? I hear you say. Well, I’ve been trawling t’internet recently and one of the chaps I follow on YouTube, Gabe, has got me very interested in this particular mode of radio communication. Here’s a video of him explaining Mesh communications in his own charming and extremely enthusiastic way.

Meshtastic – as Gabe sees it

The good thing about Mesh networks are that no licence is required for use, this means the system is truly open to everyone. As a registered radio amateur this system is of interest to me in the spirit of experimentation, and that’s what’s good about this particular mode. Everyone can do it at a very reasonable cost. In the UK it’s been present for a few years now and has an active core of participants. However, usage is very patchy and still developing, and due to the short range and lack of other users to repeat messages, its general take up is going to take a while yet, or in usual fashion it may even be a mode that just dies out due to lack of involvement. It’s not a mass-market tool yet, but a growing niche interest, especially among amateur radio, DIY tech, and preparedness communities. However, that said, in areas with little or no cell phone coverage this could well be a lifesaver. Below is a little bit about Meshtastic.

What is Meshatastic?

Meshtastic is a free, open-source project that lets you create your own decentralized, off-grid communication network using LoRa (Long Range) low power radios. It’s designed to let people send short messages and share data without relying on mobile networks, Wi-Fi, or the Internet.

Open-source & community-driven: Anyone can contribute, modify the software, or build devices with the firmware.

LoRa technology: Uses low-power, long-range radio waves in unlicensed frequency bands (like 868 MHz in the UK/EU).

Mesh networking: Devices form a mesh by rebroadcasting messages. Each device acts as a node that can relay messages to extend coverage.

Meshtastic’s goal is to provide reliable communications when other infrastructure is absent or unreliable and to offer a flexible platform for hobbyists and practical users alike.

How it works

Networking: LoRa radios transmit small data packets over long distances with very low power. Each device forwards messages it receives to nearby devices, forming a mesh network that extends reach beyond single-hop radio range. The network is decentralized — no central tower or internet access is needed.

User interaction: Devices can connect to your smartphone via Bluetooth and use the Meshtastic app to send messages or view locations. Messaging is typically text-based (no voice or high-bandwidth data).

Why use it?

People adopt Meshtastic for many reasons, often tied to availability, resilience, and independence from traditional networks:

Outdoor activities: Hiking, camping, biking: Stay in touch where cell signals are weak or absent. Location sharing: Useful for groups and safety.

Emergency situations: Natural disaster backup, communications can continue even if cellular networks fail. Communities and some groups experiment with using Meshtastic as an alternative communication layer during outages.

Technology and DIY: Education and hobbyists use it to learn about radio, mesh networking, and embedded systems. Integrations with IoT sensors and other projects are possible.

Community and social projects: Enthusiasts set up community networks, share nodes, and even run local meetup groups.

What do you need to get started?

Basically, Amazon, EBay, and the Chinese suppliers such as Ali express have all you need. Needless to say the Chinese options are far less expensive if you are willing to await delivery. Just type “Meshtastic kit” into your browser to view your options.

As I’m in the Uk I can give some prices for the most basic setups within my country. To be honest, all that is needed is a Meshtastic main board of which there are a few to choose from, a power source and a mobile phone to do the setup. Something like this below.

From Amazon in the uk I can get this board, for £18:99GBP and that’s all I need to get started.

Add to that a small battery and you can probably power this unit for between 24hrs or even a week, dependant obviously on the battery capacity and how you have the system set up. A battery in the uk on Amazon would cost around £6-£10 GBP. You can buy enclosures to make the unit “pretty” or you can even 3D print your own. I think I will print mine when I finally have my printer up and working.

On the Chinese platforms these items can be purchased at a greatly reduced price, the main board can be purchased for around £3:00GBP, you can even purchase two entire units for less than the one that you get from Amazon. It really pays to shop around.

I’m shortly going to dive into setting up a Meshtastic node, I’m even going to set up an APRS one under my radio licence conditions, but that will be another post.

So hopefully this post may introduce others to an off grid communication mode that may well assist those in remote areas or with extremely limited cell phone coverage. As soon as I’m ready to build and place my node I will write a post regarding its build, programming and eventual usage. It is all very simple technology and worth having a read about on the Meshtastic website : Meshtastic introduction

Text you soon!

TinyGS: The Open Satellite Network Anyone Can Join

It’s easy to get involved with low cost satellite tracking. Here’s a repost of a recent article about TinyGS

TinyGS is one of the most exciting grassroots radio‑space projects to emerge in recent years. Built around inexpensive ESP32‑based LoRa boards, it …
TinyGS: The Open Satellite Network Anyone Can Join

Canon power winder “A”

A very corroded Canon power winder “A” from the 70s

This is what it looks like externally, looks fine, but as this post goes on, you will notice a very marked deterioration in quality. It’s a horror story of battery acid contamination.

This unit is part of a bundle that was donated to me by my good friend Jon, see here: Cameras…i need more!

It was part of a Canon AE1 combo, the Camera i have previously posted about here: Canon AE1 35mm SLR, however the batteries within it had been left for such a long time that they had started to dissolve into the unit, leaving quite a restoration project behind. Here’s some history about this unit:

The Canon Power Winder A was originally introduced with the Canon AE-1 camera in 1975 but it also can be used with all the A series models (in fact, it is applicable to use the Winder A with the professional class Canon F-1(n) system SLR camera but without power rewind feature). It is an automatic film winder which greatly increases the automation and mobility of these manual focus cameras. Its exceptional versatility, due to its compact design provided by the principal control circuit built into the electronic circuitry with most of the electronic models such as AE-1, A-1 or AE-1 Program etc, and allows it to be attached to any models mentioned earlier and provides for its use without any special adjustments.

Winding Speed: Approximately 0.5 seconds.
Operation: When the shutter button on the AE-1 is pressed, the winder will function.
Shutter Speed Coupling Range: 1/50 to 1/1000 second for continuous photography. “B”, or 2 to 1/1000 second for single frame photography. (When the winder is set at “B”, AE photography cannot be performed).
Film Counting: Is performed by the frame counter on the AE-1.
Automatic Cut off Circuit: When the film roll is completely wound up or if the batteries should run out, the winder will automatically stop and the warning lamp (LED) will light up.
Power Source: Use 4 size AA batteries. (In normal temperatures they can take more than twenty rolls of 36-exposure film).
Attachment: Take off the winder coupler cover on the bottom of the camera, and mount the power winder using the tripod socket.
Size: 141 x 42 x 34mm (5-9/16″ x 1-5/8″ x 1-5/16″)
Weight: 3009 (including batteries) (10.9/16 ozs.)

Mir.com

I already have one of these winders on my A1 that I am currently repairing, however that’s away in storage at the moment until I get get my workspace back up and running when we eventually move home.

Im aware that these winders can take a max of two exposures per second if the lighting and conditions are right, meaning you could crack out a 36 exposure roll of film in under 20 seconds! They don’t do auto rewind either, you still have to do it manually, it would be a couple of years yet before that option became available. The red light on the case indicates one of two things, the battery is low, or the end of the roll has been reached, time to rewind!

They are quite reasonably priced if I wanted to buy one, but why would I do that? The purpose of this site is to repair and recycle, so that’s what I will attempt to do. It will be quite a task with this one I think.

Assessment:

As stated above, and from the outside, all looks well.

Outside, cosmetically, no signs of a problem

However there are a couple of giveaways that alert you to the immediate issue. Firstly there is an aroma, a kind of metallic musty smell that instantly alerts you to “Corrosion”. Secondly near the switch there are some “blue” granular stains that confirm corrosion.

We start to open up and find signs that all is not well

It’s pointless even putting batteries in here yet as they will not work, the damage is too extensive for the batteries to work. To be honest we now need to do a good clean and decontamination before we can even start to look at the extent of the contamination.

Repair:

First we have no choice but to get rid of the corrosion, this will involve brushes, a pencil grinder, and copious amounts of isopropyl alcohol. Let’s get started.

I attack the contact end of the winder with a sonic brush and some IPA. After about 10 minutes and multiple applications, using a small scraping tool i was able to remove the corrosion that had started to eat away at the chrome on the contacts, a small rub with some fine sanding paper restored the metal as best I could. I’m not going too over the top here as the corrosion could have well gone past this point into the internal workings, I’ll tidy up once I can get it working as it should.

The battery compartment was cleaned using a similar process. However the contact end that used to have springs mounted for the batteries, have all rotted and the springs have had to be removed. I will replace the springs later, it’s not required for testing purposes just yet. All this contamination and blue staining has to be removed completely, if you leave contamination behind, it can start to attack the unit again at a later date, take your time and ensure you get as much off as you can. Clean, clean and clean again. It’s a boring part of the process but essential for long term results.

With everything cleaned and left to dry, I put some power across the winder power contacts and nothing happens. No noise, not any sign of clicking or of any movement at all. Just as previously feared i think the corrosion has gone further. Let’s get it opened.

Leatherette removed to access internally

And as expected the corrosion has made its way inside, the picture above shows a wire at the contact point rotted due to corrosion, in fact the second wire fell off just after removal, the contamination has eaten the cables and is rotting the connections. The good news is that it seems that the issue hasn’t gone beyond these contacts.

I’ve now cleaned and polished the contacts at the rear in preparation for being re soldered, the issue here is that I may have to extend the cables slightly as they are quite short. This may aid my testing of the unit prior to reassembly, let’s wait and see.

I have now soldered both contacts back into position, without any extra wire, hell, it was really fiddly and I doubt it would be able to be opened again without these wires being extended a bit further. I have also thoroughly cleaned throughout the internal workings removing all signs of contamination. I have reassembled the unit and it now sits in one piece. I have taken a dentist tool to further scrape down the contact point within the battery barrel area.

Further cleaning of the contact in the battery barrel area

Using a little wire wool and IPA to clean the area I now have two good points of contact. Using the multimeter confirms we have continuity over the contacts that we didn’t have previously.

Reading the section above, you will remember that I had to remove the two springs on the battery case as they had totally corroded and broken away. I have some new ones but they are in storage, so for now I will just have to compromise until I can get to the new ones and solder them in place. Here I just obtained an old spring from a waste metal box, split it in two, added a small washer one end for the positive contact and just left the other as it was. Both springs were put in place, just being held there by the four AA batteries. As I stated this is purely for testing purposes and will be corrected once I have confirmed the unit works.

The battery holder was attached and then switched on. Nothing. Then I remembered I have to simulate the signal from the camera and this can be done by putting a metal short across the two raised pins at the power switch end. This worked, and the motor did its quick burst as expected. See the small video below.

The winder, now working. And shorting the pins to simulate the cameras signal

I’m pleased with this, as all the work I have done has been worthwhile. I just need to get the new springs soldered in place, give the whole unit a thorough final clean, ensure the leatherette that was removed is stuck back down and that the on off indicator is stuck back into place. And then we can put it onto the Canon AE1 to see if it works as it should.

On / Off switch plate glued back in place

Today I have taken out the battery spring connector and I am about to put the new spring contacts in place. I’ve found even more corrosion behind this plate so this will need to be cleaned before reassembly.

More corrosion found behind the battery spring contact plate

I’ve now fixed the new permanent springs in place, they wouldn’t solder so I’ve had to use a combination of using the old clips that were originally there and weaving the spring though the holes where some clips used to be but had corroded away. Either way it has worked well and both springs are quite solid, and don’t look out of place at all, they probably look better than the originals.

With the battery pack contamination removed I can now reinstall the battery contact back into place.

I know that the pack works, and now the final touches have been added, this winder is now back into a good working order, and fit to go back to work doing what it was originally designed to do.

Result:

This is an item you can readily buy on the auction sites at a very reasonable, some would say even very cheap price.

The complete, cleaned and reassembled, working winder

Is it worth the repair you say? Well yes, it is. The trouble is, it is so easy to throw stuff away these days, that in reality, can be given an extended life and purpose for pretty much no cost apart from your time and patience. On top of that, getting these items apart and reassembling them is a great learning circle, and you can never stop Learning. You are preserving the past, and that’s always a good thing.

A very brief video showing it working

As you can see above in this small video I have taken today, here I have my Canon AT-1 with the winder attached, doing what it is meant to do and sounding so retro with that motorised winding sound. Don’t you just love it? I most certainly do.

Thanks for passing by. It’s always very much appreciated.

Sharp OZ-7000 Wizard

The Sharp OZ-7000, Amongst one of the first electronic organisers and precursor the PDA. Needs repair. Or does it?

What the listing stated:

Not working. I have replaced the two batteries and cannot get it to work. I have not touched the memory battery. See picture for actual item. Case is a bit sticky unfortunately with age.

EBay

First of all, what is it?

The Sharp OZ-7000 Electronic organiser / Calculator

The Sharp Wizard series, introduced by the Sharp Corporation in 1989, was among the first electronic organizers and a precursor to personal digital assistants (PDAs). The debut model, the OZ-7000 (known as the IQ-7000 in Europe), combined organizer functions with an IC Card expansion system, allowing users to install software and memory cards. Over time, Sharp refined the series with larger displays, increased memory, and enhanced features, such as infrared communications port for wireless data transfer, touch-sensitive displays, and clamshell designs.

The out-of-the-box functionality of the OZ-7000/IQ-7000 included a memo pad, a telephone pad, calendar and scheduling with alarms and repeating events, multi-time zone clocks, and a calculator, thus covering all the basic functions found in PDAs since. The keyboard was not QWERTY, although later models, starting with OZ/IQ-8000, changed the orientation of the screen and keyboard layout.

The OZ-7000 was about 6.3 inches (163 mm) tall, 3.7 inches (94 mm) wide closed, 7.25 inches (184 mm) open, and 0.85 inches (21.5 mm) thick closed, making it much larger than later PDAs. It featured a serial port (proprietary connector) to attach to a Windows PC or Macintosh or another OZ-7xxx/OZ-8xxx device, an optional thermal printer port and a cassette tape backup. The OZ-7000/IQ-7000 model featured 32 kilobytes of internal memory and a 96 x 64 dot (8 lines x 16 characters or 4 lines x 12 characters) black and white LCD with controllable contrast but without a back light. A major advertised feature of the model was the IC Cards expansion slot for accessory cards developed by Sharp.

Wikipedia

A bit of a break from the mountain of photographic equipment I have been dealing with lately, I thought I’d take a bit of a detour and have a look at some prehistoric PDA gear, as I have also done in the past, as you will no doubt be aware of, if you have ever read any of my posts on Psion organisers.

From what I can gather, this one is a little beaten up and battle scarred, and quite simply does not work. I’ve paid the princely sum of £8:54GBP after i managed to knock the seller down by a few pounds. I just now have to await its arrival before we can carry out a thorough assessment.