A short video demonstrating a quick and easy way to build a charge protection board for 3s (3 x 18650 batteries in series). 3 x 18650 in series will give you around 12v. The board will help protect the battery pack from overcharging, over-discharging, over-current and short circuit.
I’ve been research designing circuit boards design and tried a few different such as eagle, ki cad and came across easyEDA which is perfect for newbies like myself. Its simple to use, the SMC (Surface mount components) selection is all tied in. You can order a PCB and have all the component (well most of them) soldered at the manufacture JCL without you have to do any soldering at all! Take a look at the video below for a quick demo
In a previous post I described how to align holes without measuring. My original alignment tool was laser cut, but due to lockdown I’ve had to devise a simpler way to acheive the same accuracy using readily available materials – this time I use BluTac and an old milk carton.
- My ‘hole’ list of videos –
- This post: 2 x jack socket holes, using BluTac and a milk carton (4:35)
- Oval USB-micro hole, using credit card and acrylic strip (2:40)
- Pin-hole for a recessed button, using only BluTac (2:28)
- Pin-hole for SMD LED, using only BluTac (1:18)
Yes it’s just that simple. This method worked first time for me. If you are unsure, drill the -holes a bit smaller and file them out to be in the correct place. A 4 minute video of this process is here.
Check out my videos for accurately marking other types of hole without measuring –
USB-micro oval cut-out (as described in a previous post here)
Pin-hole (ideal for a recessed reset button)
Pinhole on the lid to show the recessed LED of Wemos D1-mini
Visualise Active Ports
Sometimes it’s useful to know the activity on the GPIO pins of your microcontroller. This little monitor board is designed specifically for the Wemos D1 mini and has a LED on each GPIO pin to help you visualise what is happening on inputs and outputs.
This monitor is quite useful for checking DC levels and slower pulses such as when controlling servos, relays, etc. For faster pusles it’s best to use a ‘scope or logic analyser.
Microcontroller boards other than the D1 mini can be accommodated by either re-designing the layout for the extra pins, or using extension leads to monitor those pins you are interested in.
LEDs can be disconnected by removing the jumper links, so as not to interfere with other functions. All LED series resistors deliberately have a high value to minimise loading the GPIO pins. The white LEDs drew less than 500 microamps each when used with a 1K series resistor, and they were still quite bright.
The monitor can also act as a small breakout board, extending the Wemos header pins to 2 sockets and 2 pins per GPIO line. This can be handy when developing your project, as Dupont extension leads could be used to connect the monitor board to your PCB.
Construction is simple – besides the header pins and sockets, there are just a dozen SMD resistors and LEDs, mounted on a prototyping board. The underside of the board is where the connections were made, linking pins with single strands taken from a length of scrap multistrand wire.
The video shows the board with jumpers installed for all 9 GPIO ports (D0 to D8). Due to high value series resistors, the LEDs do not interfere with program uploading, and if you install the RX and TX jumpers you can watch the LEDs giving a satisfying twinkle with the upload activity.
When you are building creations in Minecraft, sometimes you need to have random blocks placed down from you hotbar. With this little program created with the help from Simon, (Thanks Simon), you now don’t have to manually spin your mouse wheel to achieve this.
Just run the python script, after checking you have the prerequisites installed (python 3 and pynput) and press ‘y’ to spin the wheel and ‘Esc’ to stop.
Link to the gitlab page.
A live docker tutorial for the Sheffield Hackspace. A run through through what is docker, benefits of docker, popular docker containers for Hackspace members (Node-Red, MQTT, Octoprint, Grafana, InfluxDB, ROS), running image as containers and how to develop using visual studio code docker plugin.
How to cut a hole to mate up with what’s inside your project box.
THE PROBLEM — You’ve made the electronics part of your project, and now need to cut a hole in your project box so you can plug in the USB cable. But how do you know where to cut? Unless the box is transparent, you can’t see exactly where the USB socket hole should be. There is a short (2:40) video of this post here.
Update: At the bottom of this post, there are links showing how to locate drill centres WITHOUT any tools.
The usual way is to measure the internal position of the USB socket when the PCB is fully in the box (not always possible) and transfer the measurements to the outside of the box. You have to be able measure and mark accurately.
This little tool provides a drilling and cutting guide on the outside of the box, when the USB socket is on the inside of the box (possibly hidden from view). No measuring is required.
My design is quite simple. Overlay two strips and fix them together at one end – similar to tweezers. The strips staddle the wall of the project box, one strip inside the box, the other outside. The inner strip is fixed into the USB socket, and the outer strip has guide marks for the required opening.
The inner strip — should be reasonably thin so it can fit between the PCB and the box. I cut a 10mm wide strip off an old credit card, narrowed it at one end to make a tab that fits snugly into the USB socket, then bent the tab 90 degrees (warming helps but is not essential).
The outer strip — should be stiff transparent material. At one end, mark where the cut-lines and drill holes should be for the USB socket. Align the inner strip’s tab with the outer strip’s markings, then fasten them together at the other end. That’s it!
USAGE — To use the template, insert the tab into the USB socket and slide the circuit board and the inner strip into the box. Ensure the outer strip is flat to the outside of the box and use the cutting guides to mark the box. My original marks were the drill-centres for a couple of 6mm holes. Use a drill press for accuracy, and a small file to smooth and adjust the drilled holes to the final shape.
This technique will work on plastic or metal, and can be adapted for any shape of socket and hole. Draw the marking guide to accept the largest plug you may use.
CONCLUSION — Cutting holes in the right place is something I have always struggled with. I have to admit I was amazed when this worked first time!
Credit goes to Alan Bailey for helping implement this project from concept to completion in just a few hours. Below areYouTube links showing how it’s done, and how to locate holes WITHOUT any tools.
I needed a new bag for my Brompton bike. All the bags were very expensive, £70 for the basic bags so I did what any maker would do and started on the journey to make my own bag. There was a few challenges:
1 . Find a way to connect the bag to the front carrier block securely.
2. Find a cheaper bag that i could modify easily and thats water proof
3. Work out if anything else was need, e.g. bag strengthening.
I started by look on thingiverse for 3D printed Brampton carrier block, its always a good place to start to see how other people have attacked the problem. I didn’t find anything. I set work to design one myself using fusion 360 – Matt SB gave me a helping hand to get started with as its the first functional 3d object I’ve printed. I came up with the item below after a few iterations printed on my Aldi 3D printer.
The next challenge was to find a bag. I search on the internet and i purchased a bag from aliexpress for £4 to test the process out. The test went fine and I used the bag for about a year but the wear and tear took its toll on the bag so I bought a better quality bag from decathlon shown below. This is the bag that i will describe on the rest of the blog.
I’ve got the carrier block designed and the water proof bag. Now I need to attach everything and make sure it wont damage the bike/contents of the bag. The back board in the bag was a bit bendy and I’m carrying my laptop to and from work so I wanted it to get there and back in one piece. To strengthen the back I bought a A3 clear polycarbonate makrolon plastic panel Sheet 3mm thick from ebay. This went down the back of the bag to strengthen it. I sawed it to shape to start with and then bent it using the hot gun in the hackspace. This gave the bottom of the bag something solid so the laptop or other items in the bag wouldn’t sag and hit the front wheel. I also added some neoprene foam to the bottom of the plastic sheet to cushion any items put in the bag.
The next task was to attach the bag to front carrier block. I did this using a hand drill and screwed it together.
I wanted a separate area for the bag.
One of our members Pixelpox has built a Minecraft server for us to all play and socialise on. It is a project that is just getting started but has already been popular with some of the members here at the Sheffield Hackspace.
Some of you are most interested in the technical details about the server so here it is.
|Minecraft Server Version||1.14|
Our members have been hard at work collecting resources and building their buildings. Some people have taken to creating farms such as sugar cane and eggs for the whole community to benefit from a sustainable source of food.
Others have been focused on village security and plain old exploring the world. Check out some of the things that have already been built.
How can I join?
It’s simple and FREE! Go to the Sheffield Hackspace Forum to subscribe online and introduce yourself. After that ask for the Minecraft details and one of our current members will get back to you with the details. Our Minecraft servers are also open to friends/family of hackspace members.
Alternatively you can join us on a gaming night that runs every other Saturday, see our events calendar for more details but importantly you’ll need to sign up as a paying member (£6/month) first which can be done on your first visit.
Gaming night isn’t just about Minecraft, members decide on the night what they are going to play in the group, this can be RetroPie and Raspberry Pi games, console games, PC LAN games, board games and much more!.
Designed and built at the Sheffield Hackspace using an arduino and bits and pieces of things that you might find lying around in your own home…
Here’s the setup:
An arduino (pro mini) for controlling the SG-90 servo motor
An ESP8266 for wifi access and neopixel control
A piece of gutter and downpipe for the main body
A plastic dome sourced from a solar powered garden lamp
An Aldi’s peanut butter jam jar lid (crucial)
Other bits and bobs scrounged from various unwanted poundland items
If you think this is cool wait until you see the boats!