Finding STP16DP05 in DIL package

It may have occurred to you to find an interesting device with LEDs, only to realize that it uses components that are obsolete and cannot be sourced anymore (or if they can , they may be prohibitively expensive). Such is the case with STP16DP05 in DIL (dual-in-line) package, used in a few kits by EvilMadScience.com and ModernDevice.com. STP16DP05 is a 16-bit LED sink driver still manufactured in SMD, but obsolete (and impossible to find) in "through-hole".

If you want to build such open-source popular kits as "Meggy Jr RGB" or "Peggy 2", you will have to re-design the board, replacing the DIL package with the SMD. What if you already have the PCB and are constrained to use the DIL version? The immediate solution that comes to mind is to use a breakout board with an SMD. Problem is, I couldn't find a breakout to the "narrow", 0.3", DIL format; they are all 0.6" wide.

So, the only choice I had was to use a replacement DIL for the STP15DP05. The first equivalent I found was  MBI5026. Only after I received the few I bought (on ebay), I realized they have a different distance between pins (in the metric system). Complete write-off, since I have no chance to ever use these. Their complete name is MBI5026GNS. It never crossed my mind that there is a "metric" standard for ICs in DIL package. Well, lesson learned, but problem still there.
Later, I found out that MBI5026 also comes in the "inch" standard as well. Problem solved, finally.

A second choice would be A6278/A6279. They are pin-to-pin compatible with STP16DP05. Actually these are the LED drivers shipped with the "display board kit" from ModernDevice.com. (And this is how I found out about them, by buying that kit.)

This may not be directly applicable to the kit "business", but another lesson I learned is to design a board for multiple packages of the same IC, thus having a bigger selection for the parts.


Conclusion: pin-to-pin equivalents for the DIL version of STP16DP05 are MBI5026 and A6278/A6279. None of them are offered by digikey or mouser (in DIL format), but you may be able to find them on ebay, expecially the MBI5026. Pay attention to what you order though, since MBI5026 comes in 2 different DIL packages. Anyway, new projects designed around STP16DP05 should not rely on the DIP package. (Note: This is the case of ClockTHREE and C3Jr, both of which use STP16DP05 SMD on breakout boards. Smart.)

LiPo batteries and charger shields - part 2

This should be an update to a previous post (I am too lazy to edit that nicely).

I bought two LiPo battery shields, one from Seeedstudio, one from cutedigi. None came with a LiPo battery. I guess it is assumed that the user selects the battery that suits his needs. My main need was for a battery that fit between the headers and was lower than the height of the headers, so that another shield can be stacked on top. Guess what: it's not easy to find such a LiPo battery. The round, AA or AAA-compatible ones, are out of the questions because of their size. The only candidates would be those silvery-flat-rectangular ones, as those pictured below.

The best match for the "Solar charger" from seeedstudio is the third LiPo in the photo, with a capacity of 1,000mAh. For comparison, 3 AA rechargeable batteries (1.2V each, making a similar 3.6V) usually have a capacity of 2,200 - 2,800mAh. So this flat LiPo battery would be a bit less than half of the capacity of the space-consuming and heavy pack of 3xAAs.

The next photo shows the LiPo battery installed in the shield.

Updated Nov 4, 2001
The "solar charger" from seeedstudio I have is V1. It is currently discontinued and replaced by "Solar Charger Shield V2". I don't know if there was a technical issue with V1, but my shield has the male headers shorter than the regular size. While building CubeClock, I had trouble with the contacts: some of the signals (A0 and A1, required by the buttons on the mini display shield) did not get passed the charger shield. After some investigation I figured that the charger shield was the culprit, specifically the shorter pins. The new V2 charger shield seems (from the photos) to have solved this issue.



All of the above batteries were purchased from seeedstudio. The second from left in the photo is sold as the "DSO Nano replacement battery" and dimensions were not published at the time. Now you can see it's a bit shorter than the 1,000mAh LiPo and almost 50% thinner.

A nice battery, size-wise and capacity-wise, is the right-most one in the photo. Although it does not fit on the top of the shield (and between the headers), it can be used underneath if you find a method for attaching it (I am still thinking).
Other bigger-capacity LiPos (e.g. 3,000mAh, 6,000mAh) are built by sticking together in shrink-wrap several of the ones shown above.

As for the charger shield from cutedigi, I cannot find an immediate use for it. It can only be used as the top shield, since it does not have extension headers. Also, the space for battery is quite small. The 500mAh LiPo can somehow fit, as shown in the photo below.

 The battery would also need to be attached somehow; plastic ties come to mind, maybe this is the purpose of the 6 holes in the board. The 3 LEDs (top-left corner) should be left visible, yet another restriction on placing the LiPo battery. Maybe it's not for nothing that "600mAh" is written in the silkscreen of the board. Cutedigi may have designed this charger shield for a specific battery, which they don't make available.

As always, your comments are appreciated.

From the "fan club" - LindorClock

Fellow Arduino enthusiast Anjan sent me these photos of his own interpretation of IllyClock, encased in a "compatible" Lindor chocolate case. I think it looks great.

From the email:
I put this one in a Lindor chocolate case and so the name. I had to cut the Lindor case to almost 2/3 rd the height to make it fit and look nice. The front design is still not complete, as you can see the  components and wires inside.

He used his own LED matrices with my Dual bi-color LED matrix shield, hence the wires and the prototyping board in the next two photos.

Keep up the great job Anjan. You are an inspiration to others.

Wyolum 2011 Innovation grant

Here is some motivation for you: Wyolum is offering two "$1,000 Innovation Grant" to the most qualified open source project applications submitted from now until Dec 3, 2011.

From the "news release":

WyoLum, LLC’s mission is to “Promote Open Source Hardware”.
To that end, we are pleased to announce two $1000 (USD) grants to be awarded to the most qualified applicants.

Entries will be evaluated on:
● Innovation
● Originality
● Technical feasibility
● Commercial viability
● Planned use of funds
● Timeline (Projects with goals that can be achieved within six months after the grant is awarded will score more favorably.)

Qualifying projects will be 100% open source (hardware and software) from development through to production. WyoLum team members will be available for advice and assistance throughout your project. If you have a killer idea, but have never fabricated a PCB, programmed a micro-controller or designed an enclosure, don’t let that stop you from submitting your idea. If we can’t immediately assist you, we will learn it together.

Submit completed applications to grants@wyolum.com by December 3, 2011. Applications will be excepted in a combination of video (encouraged), html, .odt, .doc, .docx, blogpost. We will make all reasonable efforts to receive and evaluate your application.

Hacking Meggy Jr. RGB

You have a Megga Jr RGB "game console" from EMSL and you are tired of playing or writing new games for it. How about making it into a clock?
This takes a bit of hardware hacking on your side; I provide the basic-clock-functionality sketch (download here).
In the end, the "Meggy Jr Clock" will look and work as shown in this video.




Here is a list of what you need (beside an working Meggy Jr):

• DS1307 and a 8-pin socket;
• crystal (32768Hz);
• coin battery (CR1220) and a holder for it;
• a small piece of prototyping board;
• 2 pieces of 6-pin female header;
• 6-pin right-angle male header;
• a few wires.

We will start with hacking the Meggy Jr board, which involves 3 steps:

• remove the FTDI connector; you know the drill: desoldering wick, pliers etc;
• in place of the FTDI connector solder a 6-pin female header;
• connect, with a short piece of wire the 2 points as shown in the picture below.

The hacked Meggy Jr board will look as shown in this photo:

Next, we will build, on prototyping board, the circuit for the real-time-clock based on DS1307, as shown in the datasheet. We will use the 32768Hz crystal and the 3V coin battery (CR1220, with holder).

There are two requirements for the small RTC board we are building:

• it will have a pair of 6-pin male headers that plug into the new headers we just installed on the Meggy Jr board;
• it needs to fit in the small space above the processor, between the Meggy Jr edges, the buttons and the LED matrix.

So here is how we are going to do it:

- cut the piece of prototyping board to size;

- place it on the spot, above the headers;

- solder the 2 headers (which are already plugged in the female headers);

- place and wire the RTC circuitry;

- solder the new FTDI connector (6-pin right angle male header) at the top of the board, close to the edge (above the old one we removed);

- connect each of the 6 pins of the FTDI connector to the pins of the top header.

The little RTC board you built may look like in the photos below (both sides shown).

Now we put them together (plug the RTC board into the headers) and start testing.

The Meggy Jr Clock we just built will look something like this:

First, make sure the new FTDI connector works, by uploading any sketch.

Next, make sure the DS1307 works as well, by uploading this test sketch.

Once everything looks ok, upload the Meggy Jr Clock sketch. 

If you need more detailed instructions, please visit my step-by-step tutorial at instructables.com.