Word Clock based on LED Matrix

thingiverse

The layout of the letters was inspired by https://github.com/brettoliver/wordclock but the underlying code and construction is different. I have made a few versions of this over the past few years and I though I should release it as I've moved on to other projects. Previous versions included a real time clock (RTC), but this release has code that produces web page that allows you to configure various clock parameters, including your wifi details. Once saved it will reboot and show the correct time (hopefully) after synchronising itself with an internet clock. In previous versions without the web interface I controlled options via a single switch on a printed circuit board that held the wemos D1 mini the RTC and the switch. In this version it isn't necessary to have the pcb or RTC, but the switch is handy as if held in for 5-10 seconds, it causes the wifi credentials to be reset, which means on the next reboot you can change clock parameters - think factory reset button - this is set as D5 on a wemos D1 mini. The basis for this clock is an addressable 16 x 16 led matrix, controlled by pin D6 on a wemos D1 mini. Bill of materials Wemos D1 Mini 16x16 Addressable led matrix (D6) Switch (D5) 1k resistor Optional materials Usb socket if making a plug at the rear Circuit connections - overview The LED Matrix is supplied 5V and GND from 5V and G on the Wemos D1 Mini D6 on the Wemos D1 Mini is connected to the Data In of the LED Matrix D5 is connected to ground via the switch, and is pulled to 3V using the 1k resistor Circuit connections details A circuit diagram is now included in the files. I supplied a usb connection to my wemos d1 mini. The 5V pin on the wemos d1 mini was connected to the 5V connection shown in position B on the image showing the back of the led matrix (note the wiring colours may be unreliable, so pick the correct connection). The ground (GND) pin on the wemos d1 mini was connected to the GND shown in position B on the image showing the back of the led matrix. These are the electrical power connections to the led matrix. Note, if all the LEDs are on, then the led matrix can draw a lot of current, possibly more than the usb connection can supply. INSTEAD of the USB lead to supply power, it is possible to use eg a 5V power supply and supply the leads on the matrix in position B from that power supply and then also connect the wemos d1 mini 5V and GND to those wires, ie power the wemos from the power supply. In my tests I did not find this to be necessary, and in most instances only a few leds are on, but I mention it in case you would like to not use the usb wire. The LED matrix panels have 3 sets of wires (A, B, C) in the attached photograph. I desoldered all wires in position A as they are not needed in this project, as they are for daisy chaining additional matrices. I connected power to the wires at position B (as mentioned earlier). The power wires at position C are not needed either, so I also desoldered them there too. The D IN (data in) wire on the matrix is where the instructions that control the LEDs are fed into the matrix, so the DIN wire in position C needs to be connected to pin D6 on the wemos d1 mini which is where the instructions are being sent from. The reset switch is used to 'factory reset' wifi credentials to allow them to be changed. One side of the switch is connected to the wemos d1 mini at pin D5, the other side of the switch is connected to GND. In this way, when the switch is closed, D5 will be pulled low. In order to ensure that we always get a high reading unless the switch is closed, a 1K (value not critical, 1K to 10K should be OK) resistor is connected to pin D5, and the other end of the resistor connected to the wemos D1 mini 3v3 pin, ie D5 is pulled high unless the switch is closed. Hopefully the diagrams and instructions explain the wiring that's needed, however I have also included a picture of a pcb that I had made for this clock - please note however that some of the wiring on that pcb is not needed any more, as it was made for a clock including an RTC to maintain and set the time, whereas I rewrote the code to allow the time to be set from the internet - so don't get too confused - it was also my first ever pcb, so it's far from perfect. These matrices sometime differ in how they work, so if it shows gibberish you may need to adjust the neomatrix settings eg NEO_MATRIX_ZIGZAG, or the RGB order. Using a microcontroller it is possible to determine the time, and control which leds light, and thereby make a functional word clock. The body of the clock is printed in one piece, which is mostly opaque to light. The trick is to print the masking filament (eg black) for most of the print, then for 4 layers switch to white filament, and then switch back to black filament. This is easy if you've a multi colour printer, but also possible if you've a single extruder. The body is printed with the text uppermost. You will need to add supports. This is the best way to keep clear/sharp letters (don't use ironing on the upper surface, it just makes it look dull). The body is printed in black filament up to layer 117 Layers 118,119,120,121 are printed in white filament All subsequent layers are printed in black filament. I achieve this in cura using the post processing options, and using the Pause at height script. I used 2 instances of the script to pause at layers 117 and 121 to allow the filament change. To help with these changes I used gcode to move the print head 30mm up so I could purge the extruder so the new colour filament was flowing, then the print head was lowered 30mm and the print resumed. See https://the3dprinterbee.com/cura-pause-at-height-guide/ for more details. ************************************ I recommend doing a few tests prior to doing the big print, just to make sure the correct layer settings are applied to save time and filament. As if you switch filament colour to white too late, or black too early, then the light will not pass through the words and the clock will not work. ************************************ Once printed, I used hot air on the face of the clock to remove any stringing around the letters, and with heat, a knife, and tweezers corrected any minor defects around the letters. The other parts are printed in black. The led matrix can be soldered to the wemos D1 mini, and the reset switch attached too. The led matrix should fit into the grid that prevents light bleed. The led matrix can be hot glued into place. The back of the clock is designed to clip onto the body. There are various holes for the stand, for wall hanging etc., and there's a hole for the insertion of a usb connector, and also a redundant flexible button strip for pressing the reset button. You may have to insert a custom hole for a usb lead depending on your mounting position, this could be done in the model, or via a drill after printing. You will need to do some tweaking to keep the led matrix against the grid. This can be via tape or glue. I also used some fire retardant foam inside the enclosure between the matrix and the clipped on back. There is a slight lip around the text. This is by design, as optionally you can pour some clear epoxy onto the text, making sure to get rid of any bubbles. Once set this should create a glass-like face to the clock - it looks good, but it's a one-time-only process so make sure you get rid of all the bubbles, and don't test that it's set with your finger, otherwise you'll have a nice fingerprint on yours (don't ask me how I know). The code is in the attached ino file. It should work OK though there is a little cruft in it from previous versions. On first boot there will be no wifi details saved. In that case it will make a hotspot - connect to the wifi ssid Clock Settings 192.168.4.1 The password is thirdstroke The speaking clock use to say “At the third stroke it will be X, Y precisely”. If you don't know what a speaking clock is then you're probably younger than me :) Point your browser to 192.168.4.1 and you will see a web interface where you can Enter your wifi SSID Enter your wifi password Select your timezone Select the colour of the clock text Control whether the seconds are displayed on the clock Control whether the clock dims at night Customise the dimming and rebrightening times (in case it disturbes your sleep) Control whether animations are shown Press Save and the clock will reboot and use your settings. **************************************** UPDATE On 20221005 - I was made aware of a bug by Sparekey159 - though I think other early adopters had come across it too. The wifi credentials weren't saving and so the clock wasn't working. I have now updated the code file and released V1.01 which fixes the bug, and added a lot more comments to the code for trouble shooting. Please note, owing to a Thingiverse bug, if you download the zip of all files you download the version with the error in it (wordclock.ino). So download the fixed version - wordclockrelease.ino separately from the list of files to get the latest working copy. After uploading for the first time, the D1 mini will boot and try to connect to wifi 30 times, there are no wifi settings yet, so this will fail, and it will create the access point and web page for you to enter those details and set your clock preferences. The D1 mini will save and reboot, try to connect to the wifi (up to 30 times) generally after a few attempts it will connect, update the time and display it. The serial monitor shows a lot of what it's doing now so should help with troubleshooting. Sorry that this bug got through - I think my development chip had at one time the correct details saved, and when I edited the code and accidentally broke the wifi config saving, I didn't realise, as mine still had a valid saved copy. ***************************************** Exposure in the youtube video is off a bit, it looks better off camera https://youtu.be/oS3EU70RkVE Disclaimer This clock should run and work without issue. It should only be built by someone who is capable of soldering and using electricity safely. The code and the hardware instructions are provided without any warranty or guarantee of fitness for purpose, and if you build it then you do so at your own risk.