Sunday, June 24, 2018

WiFiChron adapter for DL-1414 displays

WiFiChron has now support for the obsolete (?) DL-1414 displays. I know, the question everybody is probably asking is "why bother?" The immediate answer is because these displays are cheap and easy to find (on ebay or Chinese electronics suppliers), compared to the HDSP-2534. I actually got a few as a gift from Mr. Kin, thank you very much!

DL-1414 is a 4-character 16-segment parallel intelligent display, the grandfather of HDSP-2534: put an ASCII code on the data lines, then flick the WR line, and there you have it, a character displayed at the position specified by A0 and A1 bits. It really does not get any simpler than this. The character set definition, also similar HDSP-2534 (only defines upper case letters though) is stored internally, so there is no need to manipulate any of the 16 segments individually. Although the magnifiers ("bubbles") make them look somehow like QDSP-6064, the DL-1414 display is much smarter, and therefore much easier to interface and program.

Below are some photos of the prototype adapter for the HDSP clock horizontal mod (more of them shown here).

The adapter PCB I designed is available from oshpark (not tested though).

Note that the DL-1414 display is higher, so it won't fit in the Serpac A20 enclosure, but it will fit in the Serpac A21.

Adapting the HDSP/WiFiChron code was super easy. The only functions requiring change are writeChar(...) and writeDisplay(). The next images show these 2 functions side by side, for DL-1414 (left) and HDSP-2534 (right):

Note that the 2 chips share the D0-D6 and A0-A1 lines, but WR lines are separate, which allows individual control of each chip.

In the end, the DL-1414 offers the same functionality as HDSP-2534, at a lower cost, but also with less visibility (characters are about half the size) and less coolness (harsher "font", no lower case).

The DL-1414 experiment opened the door for future WiFiChron displays. Essentially, any 8-character display can be adapted by modifying the two above mentioned functions. This will be next. Stay tuned.

Tuesday, April 17, 2018

Upgrade your HDSP clock to an NTP-synchronized WiFiChron

So you have the simple HDSP clock but you wish you had the NTP-based time synchronization and the weather feature of the WiFiChron (not to mention the alarm). The "solution" is to buy the WiFiChron kit :)

The alternative "solution" is to hack your HDSP clock, by adding a proto-shield with an ESP8266 module, a 3V3 regulator (e.g. MCP1700) and a buzzer, the components that make the difference between the two clocks.

Before building the ESP8266 proto-shield, perform the following 4 modifications (highlighted in the next photo) on the HDSP board:
  1. isolate the FTDI's CTS pin (second from the top) by cutting its traces to the ground;
  2. wire the newly isolated FTDI pin 2 to pin 16 of the processor (D10, used for the buzzer);
  3. cut the trace connecting pin 1 of the LED display (RST) to pin 3 of the processor;
  4. solder the right angle FTDI male header on the back of the board, towards the USB plug.

The small proto-shield, that looks like in the photos below, will plug in the FTDI header. Naturally, the same FTDI header is used for either the FDTI breakout (to upload sketches) or the ESP8266 proto-shield.

Besides the hardware, one little software change (of the original WiFiChron sketch, available here) is required as well, due to the second button connected to A3 (instead of A1 as in WiFiChron):

    #define PIN_BTN_UP 17  // A3 in hacked HDSP
// #define PIN_BTN_UP 15  // A1 in WiFiChron

Since the 3rd button ("Down") is missing on the HDSP board, only the "Up" button function will be available (the left button).

Follow this post to set up the network connection.
And remember, the ESP8266 baud rate MUST be lower than 115200 (set it to 38400), since the ATmega328 with internal clock cannot handle this speed reliably (according to the datasheet, the drift is about 8%).

Thursday, October 19, 2017

WiFiChron "user manual"

With the daylight saving time ("DST") fall back fast approaching (Nov 5, 2017 for North America), a few explanations and details are required to prepare the WiFiChron clock to automatically set itself.

As much as I would like the menu items to be intuitive, I have to acknowledge that some of them look a little cryptic, and the reason is the 8-character space constraint of the display. Below is the list of all menu items, in the order they appear when the "Set" (left-most) button is pressed.
  1. Alrm on/off - alarm on or off by pressing either the "Up" or "Down" button;
  2. Al 00.00 - alarm time; first set the hours (flashing) by pressing either the "Up" or "Down" button, then move to the minutes by pressing "Set" (minutes will flash); set minutes with "Up"/"Down" buttons;
  3. HH.MM.SS - current time; move from hours to minutes, to seconds by pressing the "Set" button; set the flashing value by pressing "Up" or "Down";
  4. 12/24 Hour - display time in either military (24 hour) mode or am/pm (12 hour) mode;
  5. Scroll 4 - text scrolling speed;
  6. Chimes Y/N - chime (or not) every half hour (top and bottom of the hour);
  7. Moon   Y/N - display (or not) moon phases, in scrolling words (calculated based on the date);
  8. Brite  27 - display brightness;
  9. Yr    2017 - current year;
  10. Month 1 - current month;
  11. Date  1 - current day of the month;
  12. TzHr -1 - time zone hours offset;
  13. TzMn -15 - time zone minutes offset (some places, e.g. Newfoundland and Labrador, use half-hour offsets);
  14. WiFi  Off/On/Ini - connect (or not) to WiFi network (see this post for details);
  15. DST En Y/N - enable or disable automatic time self-adjust when DST changes;
  16. DSTsm 3 - stands for "DST start month"; month for DST spring forward, by default set to 3 (March);
  17. DSTsw 2 - stands for "DST start week"; week of the month for DST spring forward, by default set to 2 (second Sunday);
  18. DSTem 11 - stands for "DST end month"; month for DST fall back, by default set to 11 (November);
  19. DSTew 1 - stands for "DST end week"; week of the month for DST fall back, by default set to 1 (first Sunday);

Here are some photos, courtesy of Tom, of his custom-enclosed, WiFi-enabled, WiFiChron.

Thursday, September 14, 2017

Remixed WiFiChron board

Thanks to all buyers who waited patiently for the new batch of re-designed WiFiChron PCBs to arrive.
The new board eliminates the need for the 2 extra wires on the back (that connected Rx and Tx to ESP8266). The XBee socket, intended for the $45 GPSBee, was also dropped, and replaced with a 3-pin header, used for connecting the $5 GPS modules available on ebay.

Here is the list of notable changes:
  • the only RTC now supported is DS3231;
  • DS3231 is now powered from the regulated 3V3;
  • GPS module is now connected to D17 (already supported in software);
  • as mentioned above, Rx and Tx already connected to ESP8266 module (no need to solder the 2 wires on the back); as before, remember to unplug the ESP8266 module from its socket when uploading a new sketch;
This is how the new board looks like:

and assembled:

Below is the new schematic (compatible with the old one, just re-mixed):

The latest release of the WiFiChron software should still work unchanged with the new board.

On the assembly front, youtuber 12voldvids put together this nice video:

Here is another video on WiFiChron, courtesy of RayS:

If anyone else would like to make and publish videos on any of my kits, I will gladly support it, with explanations/clarifications and, obviously, discounts :)

Monday, July 24, 2017

IV-3 VFD confusion

So you want to build Axiris's IV-3 shield for Arduino, sourcing the IV-3 VFD tubes yourself, from any of the numerous ebay sellers, as I did.

Firstly, it is important to note that, although the assembly manual for IV-3 shield refers to it as "IV-3/IV-3a/IV-6 VFD shield for Arduino", which would make you think one could install either IV-3, IV-3A or IV-6 tubes, this is not quite the case. The reason is the difference in pin configuration:
  • IV-3: 9-segment + dot, 14 pins (1 not connected)

(pin configuration is bottom view)
  • IV-3A and IV-6: 7 segment + dot, 12 pins (1 not connected)
(pin configuration is bottom view)
  • and then, there is IV-3 v-82, which I bought on ebay: 7 segment + dot, 14 pins (3 not connected)
(pin configuration is top view)

IV-3 v-82 (as I named it, based on the printing on the back of the tube), is an amalgamation between IV-3 and IV-3A:
- can be found in either 7 segment or 9 segment (+ dot), although only 7 segments are connected;
- has 14 pins (as to support a 9 segment digit + dot), with 3 not connected;
- pin sequence differs from both IV-3 and IV-3A;
- the "key" (the trimmed unconnected pin) is on the opposite side compared to IV-3/IV-3A.
Below are some photos, with the "axiris" IV-3A on the left.

(Also notice the color of the ceramic insulator, white for the "axiris" IV-3A, pink for the IV-3 v-82.)

To adapt the IV-3 v-82 tube to the Axiris board, the pins need to be scrambled like this:

which leads to this ugly assemblage:

It would probably work with proper heat-shrink tubing around the tube terminals, but I preferred to order the correct IV-3A for which the board was designed.

Conclusion: Pay attention when (and if) you order the tubes for "Axiris IV-3 VFD shield" separately. The sure bet is to order IV-3A, with the white ceramic insulator, and the trimmed pin on the right side (when looking at the digit).

P.S. Also, make sure the tubes are "mirrory" black at the top. If the top is white, then the tube is damaged for sure, air got in the tube (basically the tube's glass is cracked), like in the photo below (right tube is damaged).