Dot matrix clock project *COMPLETED* - Page 1
Forum section: electronics / projects

author: Arp
author_rank: Unknown
timestamp: January 16, 2014, 11:17:52 pm
content: Always wanted a dot matrix clock. Will post some progress hereRight now it's going to be four 8x8 dot matrix modules daisy chained with MAX7221, PIC32MX controller, and a RTC IC. Will see what else might be interesting as the project evolves.Today I finished the dot matrix module PCBs, and they seem to work pretty good. Clock will be modular in case I change my mind and want to reuse some of the parts in the future O0Thought I'd test 1 mil to 10 mil tracks. They all made it out alright oddly enough. Getting things right at last

author: Arp
author_rank: Unknown
timestamp: January 18, 2014, 11:32:08 pm
content: Added a DS3232 RTC to the project board. Got it to interface properly after fumbling around with the probes in the wrong places for a few hoursOrdered some tinted dark plastic sheets, used for cars, on ebay. Hopefully if it'll work disguising the dark leds behind the soon-to-be front case windowNow to the the user control for setting time/date etc*edit Perhaps I should look into GPS module or something automatic*

author: Relaxed
author_rank: Contributor
timestamp: January 19, 2014, 12:29:28 pm
content: Nice looking project!Which method do you use for etching your pcbs?

author: Arp
author_rank: Unknown
timestamp: January 19, 2014, 02:49:50 pm
content: Quote from: Relaxed on January 19, 2014, 12:29:28 pmTracing paper, UV-leds, NaOH for development and HCl + H2O2 for etching.I use a HP LaserJet that I found in the garbage at work. It improved the blacks so one paper layer/PCB side, is enough. My older Brother printer was pretty awful. Had to stack 2 layers each side to get a proper density, and doing thin tracks didn't work very well.

author: 8086
author_rank: Super Contributor
timestamp: January 19, 2014, 08:30:40 pm
content: Quote from: Arp on January 18, 2014, 11:32:08 pmI'm using a Maestro Wireless A2235-H for this exact purpose.http://uk.mouser.com/ProductDetail/Maestro-Wireless-Solutions/A2235-H/?qs=sGAEpiMZZMvmogu7fABzFnpYRkS6GG2xhttp://simonjrichards.co.uk/word-clock-log/

author: Arp
author_rank: Unknown
timestamp: January 20, 2014, 02:48:54 pm
content: Quote from: 8086 on January 19, 2014, 08:30:40 pmGot a NEO6MV2 module coming in from China. Not sure about the longevity of those, but the price is pretty much the same as in your link minus the €20 shipping

author: Arp
author_rank: Unknown
timestamp: January 20, 2014, 07:30:21 pm
content: http://youtu.be/MUgRUxCJ8O8Testing some sliding numbers

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: January 21, 2014, 02:38:06 am
content: How about the last second digit being non sliding and the others sliding, that would get people to look twice; not quite sure what they thought they had seen

author: alank2
author_rank: Super Contributor
timestamp: January 21, 2014, 03:44:01 am
content: Looks great. One thing you might try as well to make more use of your pixels might be a larger font for the hours an minutes and leave the seconds at 3x5. Maybe 4x7 foe the HHMM.Pixels wide might be:Hour4+Space1+Hour4+Space1+Colon1+Space1+Min4+Space1+Min4+Space1+Colon1+Space1+Sec3+Space1+Sec331 wide.

author: Arp
author_rank: Unknown
timestamp: January 26, 2014, 12:15:16 pm
content: Tested alternating direction of number updates, and it looks pretty neat. Will have to rethink the "animations" and the font, but as the layout seem to be in a changing state I reckon I should wait until it's finishedAdded a second row to include date and temperature as there were some "spare" MAX7221 laying around.Been pondering about the case. Tested an old IKEA frame and it's a perfect fit for 4x3 modules, all thou you lose the left, right column and top and bottom row.Going to try to modify it for 4x2 instead, saving the bottom and top row.

author: Dave
author_rank: Super Contributor
timestamp: January 26, 2014, 12:22:08 pm
content: Neat project.I think the LED display would look even better if you would put a thin layer of smoked grey plexiglass in front of it.

author: Arp
author_rank: Unknown
timestamp: January 26, 2014, 12:33:16 pm
content: Quote from: Dave on January 26, 2014, 12:22:08 pmThanks. These maxim circuits are some pretty smooth to work with. Too expensive thou. Will use regular cheap bitshifters next time, with the RGB versionOrdered a dark and medium black plastic roll on ebay (http://www.ebay.com/itm/111235140026?item=111235140026&viewitem=&sspagename=ADME:L:OC:US:3160&vxp=mtr). Thought it might work behind the glass. Will look into colored plexiglass if it's a no-go*edit* Found a sheet of gray plexi on ebay UK. Couldn't resist to try it out, so I will in a few days

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: January 26, 2014, 09:59:39 pm
content: http://www.ebay.co.uk/itm/130733916831?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649$4.45 for 10

author: Arp
author_rank: Unknown
timestamp: January 29, 2014, 04:58:23 pm
content: Quote from: Mr Smiley on January 26, 2014, 09:59:39 pmI've had bad luck with cheap Chinese components in the past. And even if they work, you never know for how long

author: Arp
author_rank: Unknown
timestamp: January 29, 2014, 05:03:39 pm
content: Been playing around with some polarizing plastic found in a discarded LCD panel. Pretty easy to tune it into the correct shade by rotating one of the sheets. Now only the leds are visible*edit*http://youtu.be/L_KJ8zHUiQ4a viddy of the clock ticking.. Gonna try to make the transitions a little more interesting

author: jeremy0203
author_rank: Contributor
timestamp: January 29, 2014, 10:29:08 pm
content: that looks sweet. i have a few of those dot matrix drivers i got from cheaper for super cheap with the drivers to just mess around with.i would change the time seperators, move the top one down one and the bottom up one.

author: Dave
author_rank: Super Contributor
timestamp: January 29, 2014, 10:33:25 pm
content: Wow, she's a beauty.

author: alank2
author_rank: Super Contributor
timestamp: January 30, 2014, 01:38:29 pm
content: That looks fantastic! Good job!

author: KarlosVandango
author_rank: Contributor
timestamp: January 30, 2014, 05:21:17 pm
content: Hi,That's a nice project! Just checked out your vid links on the clock... Very cool!Regards,Karl

author: Arp
author_rank: Unknown
timestamp: March 07, 2014, 04:22:38 pm
content: Thanks guysI moved the time separator. Looks betterSome updates:Tested a cheap "Blox NEO-6M-001" GPS module found on eBay. Won't lock on satellite unless in the window. Ordered a Skylab MT3329 SKM53 module that is supposed to be more sensitive. Will see in a month or so. Ships from China so it's gonna take a while. Think I'll etch a button controlled PCB in the meantime, but with support sockets for the GPS module.*edit*Also added a photo sensor for light dimming

author: Arp
author_rank: Unknown
timestamp: March 30, 2014, 02:29:13 pm
content: Recieved the Skylab module about a week ago. Not as sensitive as I'd want it, but will do.Etched the "mother"board today. Had to add a budge wire. Forgot to connect one of the ICSP pins.Board wouldn't work at first, but after desoldering and resoldering 90% of the components it started working. Looks pretty messy as a result

author: Arp
author_rank: Unknown
timestamp: April 05, 2014, 02:56:49 pm
content: Got the GPS working with the clock now.GPS module is drawing ~50mA. I wonder if I should let it be on 24h or switch it on for occasional reads? Not sure about its life expectancy.Wrote a DateTime library so I can add hours to the UTC and it'll calculate everything according to leap years and days of month.Still need to add day of week support to switch it on/off summertime automatically. Wish the GPS data already contained that info

author: Arp
author_rank: Unknown
timestamp: April 26, 2014, 06:29:12 pm
content: Been running the clock in the window for some time now, streaming directly from the GPS module and everything has been working according to expectation.I will call it a quits for now and jump on to next project. Probably something involving a few WS2812 LEDs for some pixel art

author: TerminalJack505
author_rank: Super Contributor
timestamp: April 26, 2014, 06:45:26 pm
content: Nice looking project. Well done!

author: shailesh3t
author_rank: Regular Contributor
timestamp: April 27, 2014, 10:59:08 am
content: I have bought the Dot matrix Too , would you mind sharing your code and a brief explanatationthanks in advanceshailesh

author: Arp
author_rank: Unknown
timestamp: April 27, 2014, 12:52:47 pm
content: It's pretty messy right now with a lot of experimenting and redundant code, but I'll clean it up and post a link here asap

author: Arp
author_rank: Unknown
timestamp: May 01, 2014, 08:13:26 pm
content: Quote from: shailesh3t on April 27, 2014, 10:59:08 amHere's the XC32 project. It is pretty crude, so sorry about the lack of comments, but it should be pretty straight forward. The DateTime library doesn't support decrement of time as I only needed increments, but can be pretty easily added.Basically there's an interrupt trigger on the UART (GPS) that updates the led modules. There is supposed to be a DS3232 backup when lacking GPS data, but didn't need to implement it as it works pretty good once it gets a lock. There are still some kinks but nothing mayor*edit* managed to introduce a bug cleaning the code dealing with the ds3232 or gps. Clock suddenly stopped ticking on the night stand. I will have to go through it and post an update

author: Porto
author_rank: Contributor
timestamp: May 12, 2014, 07:22:36 pm
content: I am very interested in assembling such clock myself but have much to learn I guess...e.g. When I start reading this thread I thought this was an Arduino project but I don't recognize the files in your uploaded .zip file, can you clarifyin what code this is written?Do you have the schematics of the PCB's used?Thanks and great job!

author: mariush
author_rank: Super Contributor
timestamp: May 12, 2014, 07:55:18 pm
content: The source code is written in C++ and the microcontroller is a PIC32 from Microchip.Arduino uses a custom wrapper around the C language, which is simpler than C++. You can write programs in C and compile them for Arduino or you can adapt the code in the zip to the arduino quite easily, but the arduino may not have enough memory to fit all the code in it..

author: Arp
author_rank: Unknown
timestamp: May 13, 2014, 09:54:07 am
content: Beat me to it. It's a MPLAB X project that uses the XC32 compiler. My first "real" attempt on C++I'll send you some screen caps from the PCB software. Most was drawn in PCB layout view so there really is noschematic. Maxim data sheets contains a lot of information and minimum configuration schematic and that's what I used drawing out the tracks and pads

author: Porto
author_rank: Contributor
timestamp: May 13, 2014, 06:31:43 pm
content: Hello,Thanks for the replies, I understand now.I will try to compile it to Arduino platform if it lets me because of the size.I'm very new to Arduino and C coding so I have still a (very) long way to go.

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: May 15, 2014, 07:15:51 pm
content: About fake max7219 ic's.This guy has tested several and shows his resultsThey all workedhttp://tronixstuff.com/2013/05/16/the-max7219-led-display-controller-real-or-fake/

author: krivx
author_rank: Frequent Contributor
timestamp: May 15, 2014, 07:31:59 pm
content: Where did you source the 8x8 displays? There are lots cheap on ebay but I'm wondering if poor variation in brightness will be annoying...

author: Arp
author_rank: Unknown
timestamp: May 16, 2014, 06:49:17 am
content: Quote from: krivx on May 15, 2014, 07:31:59 pmBought the cheapest modules I was able to find on ebay:http://www.ebay.com/itm/4-pcs-8x8-Dot-Matrix-5mm-Red-LED-Display-Common-cathode-/170666713027?ssPageName=ADME:L:OC:US:3160Didn't notice any variation in brightness, all thou one module had a dead pixel. It was at the corner, so never bothered to change it.