Posts with «hdsp» label

More WiFiChron variants

This post shows two WiFiChron mods, that look more like finished projects rather than just experiments.

First one uses the WiFiChron board connected on I2C to two Adafruit Quad Alphanumeric Displays (I2C addresses 0x70 and 0x71). The WiFiChron software has similar adaptation as the one for HDSP clock (see this post for details).




Did I mention that two plexiglass plates are still waiting to be cut and screwed in the standoffs?

This (poor) video shows it in action.

The interesting thing about the Chinese clones (of the Adafruit displays) I had in hand is that each module has one (2 digit) display red and the other orange. Initially I thought it's a manufacturing error, but after checking, it seems that this is intended (for reasons I do not understand).

The second one is an "HDSP clock" with a 8-character display with 16-segment LED modules, introduced here, cased in a LEGO enclosure.

After cutting the top of board off (since there is no HDSP-2534) and a little filing of all sides, the PCB fit perfectly between the LEGO bricks.




For this display, the line that has to be enabled (un-commented) in DAL.h is:

#define DISPLAY_HT16K33


Alternative displays for HDSP or WiFiChron clocks

So you would like to build your own HDSP clock or WiFiChron clock but you find the HDSP-2534 display too small or too expensive. Why not just replace it with a bigger 8-character display, like the 1-inch 8 x 16-segment or two cascaded Adafruit 0.54" 4 x 14-segment backpacks? We have you covered, in software. Both these displays are now supported, as extension classes of the DAL (Display Abstraction Layer), together with the 128x64 I2C OLED and the HT1632-based 32x8 LED matrix display (used to be from Sure  Electronics). Support could be further extended to LCD displays (think big font on 40x4), MAX6955 with 6x16 segment etc., basically anything that can show 8 alphanumeric characters (numbers only, like regular Nixie tubes, would not suffice).

Below are some examples.

Two Adafruit 4-character backpacks are connected on I2C, addresses 0x70 (default) and 0x71, handled by class DisplayAda14seg, which in turn uses the Adafruit_LEDBackpack library.


To enable this display, uncomment the line (in DAL.h, comment out the rest):
#define DISPLAY_ADA_14SEG  // 2 x Adafruit 4x14seg displays;

Functionality for the 8x32 (or 16x32) LED matrix display is implemented in class DisplayHT1632, which is based on code recycled from Wise Clock 4. To enable this display, simply uncomment the line (in DAL.h, comment out the others):
#define DISPLAY_HT1632	 // Sure 8x32 LED matrix controlled by HT1632;



To accommodate the 8 characters on a 32-pixel line, fontTiny had to be used (each character is 4 pixels wide).

Other possible definitions in DAL.h are:
//****************************************************************************************
// Define the display you wish to use here.
// Comment out the ones not used.

//#define DISPLAY_HDSP2534 // original HDSP-2534 display in HDSP clock;
//#define DISPLAY_HUB08 // TODO: 8x32 LED matrix display with cascading shift registers (?)
//#define DISPLAY_DL1414 // 2 x DL1414; tested June 23, 2018 (http://timewitharduino.blogspot.com/2018/06/wifichron-adapter-for-dl-1414-displays.html)
//#define DISPLAY_HT16K33 // my 8x16-segment driven by HK16K33, tested Jul 26, 2020;
//#define DISPLAY_OLED // I2C OLED; tested
#define DISPLAY_HT1632 // Sure 8x32 LED matrix controlled by HT1632; tested Aug 14, 2020;
//#define DISPLAY_MAX6955 // TODO: 8x16 segment driven by MAX6955
//#define DISPLAY_LCD1602 // TODO: classic LCD 16x2 (or better 40x4, with big font);
//#define DISPLAY_ADA_14SEG // 2 x Adafruit 4x14seg displays, wired on 0x70 and 0x71 I2C addresses; tested Jul 26, 2020;

// show time on the 60-pixel Adafruit Neopixel ring;
//#define _ADD_NEOPIXEL_
//****************************************************************************************


And so on.


HDSP clock fully through-hole revision 3

The only SMD component in the HDSP clock was the USB miniB connector. To make the kit completely beginner-friendly, this connector was replaced by either of its two (right angle or straight) through hole equivalents. Other changes (from revision 2) are:
  • fixed the two smaller pads for DS1307
  • some re-routing (which reduced the number of vias to 5)

The TH right angle USB connector is to be mounted on the top, as shown below.


The straight USB connector can only be mounted on the bottom side of the PCB, as shown below.


This latter configuration allows the clock to be used without any additional enclosure, with just two standoffs holding it in a vertical position, like this:


Assembly instructions for the HDSP clock kit can be found here, with the only difference being the last step, where the miniB USB connector is soldered.



Wise time with Arduino 01 Aug 02:11
hdsp  

Clock super-display

Today was a good day. In typical fashion, I started a few new "projects" almost in the same time. First one, it's assembling of a new kind of clock, from a kit sent by Nick S. I got stuck pretty early though, so I "parked" it for now. Details to come soon, in a special post.

Second one, an "Adler 121PD" vintage calculator with a VFD display, that I found "in the dumpster" (well, not really, but the idea is the same, I got it for free). I was going to break it apart, for the display and the circuitry, but I gave up when I powered it up (with an improvised cable; the original, proprietary one, was missing) and it actually worked! I may still go ahead with dis-assembling it, since it is not a great value anyway; I checked prices on ebay, and they go for around $20.

Lastly, the project that gave the name of this post: a clock LED super-display, consisting of 3 individual and independent indicators, inspired by the Leitch studio clock, brought to my attention by Nick (VE2HOT). The goal for the clock super-display is to eventually be able to emulate the Leitch clock. Here it is, in its incipient glory (only the back panel; the black wooden frame not pictured):


Since I am not the crafty kind-of-guy (also not keen on spending for form more than for content), I am always looking for cheap, easy and quick solutions for encasing electronics. In this case, Ikea's Ribba 9"x9" frame ($10) seems to be a good fit for the job, and hopefully will help the future clock look "Leitchy" or even better (Nick's photo below):


The 2 alphanumeric displays (4 and 8 chars) of the clock super-display are I2C-driven. The 60 LED ring is adafruit neopixel, controlled by a single output pin. With this setup, even an ESP8266 module could be used as the brains of the clock.

The ring is fixed to the cardboard back/panel of the deep Ikea frame with four M3 plastic standoffs glued to the PCB.
The 4-character alphanumeric 16-segment is my creation, introduced earlier. It is driven by the HT16K33 backpack, also from adafruit (not in the picture). The PCB has M3 holes for screws.
The 8-character alphanumeric is made of two side-by-side quad 14-segment LED displays, also from adafruit. The 2 modules already have the HT16K33 drivers installed (soldered on the back). Attaching these quad displays to the panel is not easy, since the holes are probably M1.4. Even these thin M1.4 screws need to be forced, because the screw head presses against display's plastic enclosure. Eventually, the M1.4 screws will be glued to the M3 plastic standoffs, that's the best I could come up with. It is weird that, for such a popular and successful product, one cannot find photos (or instructions) on mounting these modules using screws.

Next step is the software support in the WiFiChron software. Also need to find a way to access the 3 buttons: having them in the back is not a good idea, having them in the front is impossible, unless the glass is replaced with transparent/smoky/grey acrylic, which can be drilled.

Wise time with Arduino 11 May 02:13
esp8266  hdsp  i2c  wifichron  

Modding WiFiChron with GPS or Bluetooth

The latest revision of WiFiChron has an XBee socket (beside the ESP8266 8-pin socket), which allows the addition of a few individual features:
  1. GPS-based time synchronization, by using the GPSBee;
  2. displaying messages sent from a Bluetooth device, by using the BTBee/BLEBee;
  3. displaying data acquired from an XBee/ZigBee network of sensors (not implemented yet);


Things did not go smoothly, without some drama though. Naively (I always seem to forget that there is a difference between theory and practice), I designed the XBee/ESP to connect to the serial port, with the expectation that once the development (including testing with debug statements to the serial monitor) is done, I will just plug in the serial module (either XBee of ESP8266) and things will work properly. Well, I had to re-consider this approach once again. Luckily, I had two pins left available (D7 and D17), which I could use for software serial. I re-wired those to the XBee/ESP and used the hardware serial for console communication. Until the next board revision, anyone wanting to follow will need to re-route a couple of traces manually, as shown in the photos below (cuts are red-circled).


A few details on my implementation of the GPS time sync (so that one doesn't need to look at the code to figure it out):
  • user can set a timezone (stored in eeprom, default is -1); there is no (easy) way to determine if the timezone was set or not, since -1 (eeprom byte being 255) is a valid value;
  • estimate the timezone from the longitude, assuming that a every 15 degrees is an hour difference;
  • a difference between GPS estimated timezone and the user-set timezone of more than 2 hours would mean that the time is way off and the user did not set the timezone; in this case, blink the display; a difference of 2 hours or less would be acceptable (for many reasons, including summer-time, or variations from the "15-degrees-longitude-per-hour" approximation);
  • in any case, the minutes and seconds are set from the GPS data;
  • date and day are not set/synchronized at all (currently);
  • the GPS sync is scheduled to happen every 10 hours (and also after a reset);
  • a successful sync is indicated by an up arrow at the end of the scrolling date (e.g. March 29, 2015 ^).
I will publish the code as soon as I have a chance to polish it (and also test it with BTBee).

Wise time with Arduino 29 Mar 18:44
bluetooth  hdsp  xbee