These are 12 volt, 33 amp switching power supplies suitable for a range of high current uses. We used them for a public art installation that we were hired to engineer and install and they performed admirably for 3 months. We powered more than 200 feet of WS2812 LED strips with a couple of these power supplies.
Author Archive | Paul Badger
The RFM69CW radio module by HopeRF is a compact, powerful radio transceiver module for swapping data packets in the 868 MHz ISM band, using standard and enhanced FSK modulation. The radio is great for sub-compact designs; just 4mm of mounted height from using an SMD precision crystal.
Though consuming a similar level of power, the RFM69CW receiver section can decode fainter signals than the classic RFM12B, so it has better receive sensitivity. The transmitter section *maximum* output power is +13dBm, considerably higher than the +5dBm of the RFM12B. The current drain at these (adjustable) higher power settings is correspondingly higher though. With the better receiver sensitivity, many applications will not need to use the higher transmit power settings, potentially saving on battery life.
Compared with the RFM12B, pairs of RFM69 modules will generally have greater range and/or better penetration of walls/ceiling than when using pairs of the classic RFM12B.
The physical module is compatible with the PCB footprint on all current JeeNodes and JeeLinks. For details of the fast-evolving level of software support, see this Forum topic on the JeeLabs forum.
Control is via a fast SPI bus with reduced loading on the microcontroller, another nice advantage with the radio. The recommended power supply range of 1.8 < Vdd < 3.6 V can squeeze almost the last energy out of depleting batteries without needing a boost converter.
An antenna must be connected to RFM69 module – for 868 MHz, an 82-mm (quarter wavelength) wire can be used (not included). Operation without an antenna at the higher transmitter power levels risks permanent damage to the output stages.
Marking Convention: a yellow spot on the top of the transceiver chip indicates optimized for the 868 MHz ISM band. You can have confidence that you are building your project with a fully functional module!
- More transmit power than the RFM12B (but more current required).
- Better sensitivity on receive.
- An RF signal strength is available
- Fits the current RF12B footprint
- The JeeLabs driver fully supports the radio with only one definition change at the top of a sketch.
- RFM69 and RFM12B radios may be mixed in a JeeNode network and talk to each other.
For detailed specifications, see HopeRF’s RFM69CW documentation.
The RFM Board provides convenient signal breakout with an option for connecting to 5V power systems.
Digital Smarties (The JeeLab Shop) stocks a 868 MHz version of these modules with EU prices. Both Modern Device and Digital Smarties (Jeelab Shop) have the 434 versions.
Right now we are selling these on RRM12B boards and JeeNode kits.
These are 12″ long ribbon-wire jumper cables suitable for a wide variety of temporary or permanent wiring tasks. These are much more robust than flexible breadboard wires which are fine for quick prototypes, but do not hold up to soldering.
We’re even including some double-long male headers with the female pins, as handy gender changers.
They’re in the shop and ready to go.
I’m giving away ten of ten of them for free. Use coupon code RIBBON_WIRES. Limited to one per person on orders over $10.
A beautiful palette in Eagle. It’s still a work in progress.
This is tutorial to make a script that will set your color palettes in Eagle. Eagle has horrible (and limited) default colors and users have been complaining about them, and the lack of color palette functionality for the last 15 years, with absolutely no response. According to the managers at CadSoft the next revision is slated to fix some of the multitude of interface issues that are wrong with Eagle. (Don’t get me going again…) If you agree with me, you might wander over to the Eagle support forums at Element 14, and speak up about fixing the color palette, as well as storing color palettes in files.
Anyway here’s how to make a groovy script that will set your favorite palette colors. One use for a script of this type is to reset your colors if they should ever become compromised, but you can also move color palettes between computers, and include them with files that you send to others, so that they can see your beautiful work in the colors in which it was created. To set the color palettes in Eagle, just run the script.
(Sorry these are the mac instructions – windows shouldn’t be that much different. I think the file name for .eaglerc might be different. Feel free to mod my instructions for Windows and repost.)
• The first step is to edit one of the Eagle palettes to your taste and add some better colors. Don’t forget that the colors are arranged in vertical pairs in the palette. When you choose the top color in the pair in which to have a layer displayed, when the layer is selected, Eagle will use the bottom color of the pair to display the selected/active item in the layer.. If you choose the bottom color in the pair for the layer, elements do not change color when selected. So colors directly above each other in pairs should usually have a great deal in common. I usually make the selected color brighter (more saturated to you artists out there), and more opaque, assuming that when you select an item, you generally want it to pop out at you.
• Once you have finished your masterpiece palette, quit Eagle. This is important because Eagle has some bizarre ideas of when to write files, so lots of information is stored and then written out when you quit. If the program crashes, well, you lose 🙂
• Open the Terminal and type the command “cd ~” (no quotes) That will get you to your home folder just in case the terminal
doesn’t open with your home folder as the current directory
• Next type the command “ls -la” (no quotes)
That will list all the files including invisible files – which .eaglerc is, since it begins with a period.
• Look for a line similar to this
-rw-r–r– 1 userName admin 29110 Sep 26 20:29 .eaglerc
If you find .eaglerc all should be well.
• issue the terminal command “less .eaglerc”
• When the file opens in the terminal, use the arrow keys to scroll through the file (it takes a while!) until you find
a line like this:
Palette.0.0 = “0xFF000000”
These are the palette entries.
Palette.0.x entries are the black background
Palette.1.x entries are the background
Palette.2.x entries are the grey or colored background
You can copy any of the palettes for your script, or just one. I only use the white background, so I just copied the 1.x entries etc.
One strategy if you didn’t want to change the black and white palette default colors would be to change the colored background.
Copy the palette/s you want. Paste it into a text editor. At this point you can exit the terminal if you want.
• Next you need to use the text editor of your choice to search and replace commands to change the text from the form
“Palette.1.1 = “0xB43232C8”
to the form
“set palette 1 0xB43232C8;”
If you have any practice at all searching and replacing, this should only take four or five steps of search/”replace all”, to whip the text into the correct form.
next append the entries:
“set palette black;” before the black palette entries
“set palette white;” before the white palette entries
“set palette colored;” before the colored palette entries
you can add blank lines if you want for formatting – they are ignored.
comments may be added with a # sign beginning the line and ending with a semicolon
• Here’s the head of my file for an example.
# Set the default colors in Eagle Cad;
# colors are stored in .eaglesrc in your home directory;
# open that file and copy the current colors;
# Then edit in a text editor to the proper format;
set palette white;
# you can’t change index 0 in the white palette;
set palette 1 0xB41CC2FE;
set palette 2 0xB4002400;
set palette 3 0xB4008080;
set palette 4 0x96CE0029;
set palette 5 0xB4800080;
• That’s it – save your file as “MyDefaultEagleColors.scr” or anything you wish, just be sure to use a “.scr” extension.
If you get an error in Eagle when you run the script with Run Script you probably just have a formatting error. You can get an example of a working script from the “defaultcolors.scr” script in the Eagle/scr folder, to get the syntax right.
Happy palette making. This will give you a way of transporting your colors between computers and sending to others to view your Eagle files as you created them.
Remember you don’t have to get the palette right the first time, you can repeat the process any time, although it is a little tedious. In the meantime, you might speak up in the Eagle Forums at Element 14 and ask for a load and save button in the set palette window, which would make this tutorial blissfully obsolete.