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OpenSprinkler Interval Program is now available for OSPi

Jun 8th, 2013 by ray

Good news to the OpenSprinkler Pi users: the same interval program firmware that runs on the latest OpenSprinkler has now been ported to OpenSprinkler Pi! This is due entirely to the generous contributions by Dan Kimberling, who ported the OpenSprinkler’s Arduino code to Python. The code is available for download at Dan’s GitHub repository. Instructions can be found at the Rayshobby Wiki page:

Python Interval Program for OSPi

(Note: the grayed-out instructions below are obsolete and are only kept here for archiving purpose. Please follow the instructions on the Wiki page above for how to install and use the latest software. Thanks.)

For anyone who is unfamiliar with RPi, here are some basic instructions to follow:

First, ssh to your RPi (or connect your RPi to a monitor and open a Terminal), and type in run the following command in one single line(i.e. the ‘wget’ command, space, and the very long link): wget https://github.com/rayshobby/opensprinkler/raw/master/OpenSprinkler%20Pi/software/demos/interval_program/ospi.tar.gz
Next, run tar zvxf ospi.tar.gz. This will unzip the file to a subfolder named OSPi in your current directory.
Now, cd OSPi, and then run sudo python ospi.py (note that you will need to type in your RPi account password). This will start the web server.
Open a browser on your computer or any device that’s connected to the same network as your RPi, and type in your RPi’s IP address, followed by colon, and the default port number 8080. For example, for my RPi, the address is http://192.168.1.147:8080. You should now see the homepage of the interval program demo. Note that the port number can be changed to other values, in which case you need to check the source files to figure out how to make the change (or post a message on the forum and I am sure someone will help you).

This demo program is the same as OpenSprinkler 1.8.2 firmware. So you can follow the OpenSprinkler Online User Manual for usage instructions. I believe all features of the firmware are supported. Keep in mind that this is still work in progress, so there are glitches and bugs that will be ironed out over time. If you are a developer, you are welcome to improve the code or help fixing bugs. The backbone of the software is based on web.py, a popular and easy-to-use web framework for Python.

Also keep in mind that if you have RPi rev. 2 (which is the current model), you need to open ospi.py and edit a port number. Details can be found in the README.txt file. P.S., it’s generally a good idea to read the README.txt first before you start doing anything.

These will be the basics to get you started. If you have any questions, feel free to post a message on the forum.

Finally, a big thank-you again to Dan Kimberling for his time and efforts in making this available to the public. This is an example of the true spirit of open-source development and community support. I am very excited to see additional user contributions to the OpenSprinkler Pi project!

Posted in Product News, Raspi, Sprinkler Projects | Comments Off

Annoying ribbon cable problem with recent orders of OpenSprinkler Pi

Jun 8th, 2013 by ray

Hi, this is an alert to users who recently ordered OpenSprinkler Pi: we’ve found an annoying problem with the 8-pin ribbon / rainbow cable that comes with the package. Apparently many of the cables have disconnected crimp wires, causing the OSPi to not respond to RPi, or even worse, causing all stations to turn on at the same time. I estimated that there are potentially up to 60 orders that might be affected. We’ve proactively taken actions to send a replacement cable to everyone who ordered OSPi recently (within the last 2 weeks). If you are seeing an issue of your OSPi not responding to RPi, try to use a multimeter to measure the connection on each of the 8 wires of the cable. If any wire is not connected, please email to [email protected] and we will send you a replacement cable right away.

Here is a closer look at the cause of the problem. When I take the wire out of the crimp connector, you can clearly see that the good ones (shown on the left below) have metal wires tightly secured by the crimps, while the bad ones (shown on the right below) have the metal wires cut from the cable, resulting in disconnection. This is probably due to a defective wire stripper or crimp tool, or incorrect operation that causes the metal wires to be completely cut through. In any case, I’ve informed the supplier and complained about the the quality, and will never order from them again.

So the lesson to learn here is that when testing OSPi, we really should use the individual cable that goes with each board, instead of using a common testing cable. Another lesson to learn is to never overlook any part, even something as simple as a cable!

I became aware of the cable issue when a couple of users reported that their OSPi did not work. This is very puzzling because every single board has been tested and verified, so the chance of DOA is very small. I’ve asked two of them to send their boards back to me, and after testing, I couldn’t find any obvious problem — the board works fine, and all demo programs work fine. However, until yesterday, I have apparently overlooked the problem with the cable: when testing, we have always used a common testing cable, instead of the user’s cable. Partly it’s because I never thought the cable would have any problem at all. Now I’ve learned a lesson, and it’s a good lesson to learn!

Posted in Product News, Raspi | Comments Off

2013 Bay Area Maker Faire Summary

Jun 8th, 2013 by ray

First off, my apology for not updating the blog for a while. Right after the Bay Area Maker Faire on May 18 and 19, I went to a trip to the UK for about ten days. Then as I came back, I was faced with a load of orders that need to be processed immediately. My friend Don and I spent three days non-stop shipping out packages. Now that all the back orders have been processed, I finally felt relieved and can come back to take care of the blog.

As a quick summary of the 2013 Maker Faire: we had a great show. A big thumb-up to Aaron Newcomb for helping me out. Without him, I would not have made it to the Maker Faire. Lots of people came by, chatted with us, provided valuable comments and suggestions, and expressed appreciation and love 🙂 I took pictures with Chris Anderson, and Eben Upton and Liz Upton. I also met and chatted with Laen from OSH Park, Ian Lesnet from Dangerous Prototypes, Mark Frauenfelder (Editor-in-Chief of the Make Magazine), Jason Babler (Creative Director of Maker Media), Michael Caster from the Maker Shed, and many others. This is such a fantastic event, and a great opportunity to meet and make connections with other makers.

This year we didn’t bring many physical goods sell at the Maker Faire, but instead directed people to place orders online. This way we can devote more time to talk to people. Two interesting things I learned this year: First, AASaver is surprisingly popular and received much interest, but unfortunately I didn’t foresee this and hence did not prepare any new stock. What a pity! If I end up going to the New York Maker Faire later this year, I will make sure to take a batch of AASavers there. Second, kids really enjoy playing with flashing LEDs. We’ve set out a table with coin batteries and self-flashing LEDs, and provided simple instructions to make an LED throwie so people can make one right at the booth and take it away as a gift. This was hugely popular, and all the LEDs and batteries were consumed in no time. Apparently I should prepare more of these next time!

Of course the primary focus of the audience at our booth is on OpenSprinkler and OpenSprinkler Pi (OSPi). Since the release of OSPi just a couple of months ago, it has started gaining significant interest and has become the fastest growing product on my site. So far there have been more than 350 OpenSprinkler Pis out there in the wild. And as you can see from the forum, lots of people have been keenly working on developing their own software, using different programming languages and implementing advanced features such as weather-based control and sensor-based control. As I will talk about in the next post, the same firmware that’s running on the microcontroller-based OpenSprinkler has now been ported to OSPi, thanks to the generous contribution by Kimberling. So now you can run the same full-featured interval program on OSPi as in the standard OpenSprinkler.

But if you think the microcontroller-based OpenSprinkler is losing its charm, you couldn’t be more wrong 🙂 Although not growing as fast as OSPi, it’s still selling extremely well. Anyone who recently ordered the assembled OpenSprinkler has probably found out that we’ve been `secretly’ upgrading your order to a pre-release version of OpenSprinkler 2.0. As I will talk about in a follow-up post, OpenSprinkler 2.0 has an upgraded mcu (ATmega644), microSD card slot, the ability of adjusting LCD backlight brightness and contrast, more available pins to interface with external sensors and actuators, and pin headers to directly plug in an RF transmitter in order to interface with remote devices. The only difference of the pre-release version with the final version of 2.0 is in the enclosure design: the pre-release uses the current enclosure, and the final version (which is in production at SeeedStudio) will be using the new injection molded enclosure. There are many good reasons to prefer the microcontroller-based OpenSprinkler over OSPi: it is pre-flashed and works out of the box, so no hassle with installing raspbian, doing ssh, or dealing with Linux; it has LCD, buttons, and a number of analog pins to interface with external sensors; also I personally really like microcontrollers because of their simplicity and the fact that the controller is instant on when you need to restart it.

Uhh, I think my thoughts are already drifting away from the Maker Fairem which is supposed to be the focus of this post. So let me conclude this post here, and more exciting posts about recent updates will follow next!

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Preparing for Bay Area Maker Faire 2013

May 17th, 2013 by ray

Contrary to what I mentioned in a previous post, I have made the very last-minute decision to attend the Bay Area Maker Faire 2013. I will be flying out of Massachusetts early tomorrow morning, and get to the Maker Faire ground in the afternoon to do initial setup. Aaron Newcomb has kindly volunteered to help me at the booth. If you are planning to come to the Maker Faire, be sure to drop by our booth (exhibit 3375, Expo Hall with commercial makers), and watch our demos.

We will be showing most products I’ve developed so far: OpenSprinkler (including DIY 1.42u, the new assembled OpenSprinkler 2.0, and new injection molded enclosure), OpenSprinkler Pi, SquareWear (with lots of pictures of wearable electronics workshops I’ve hosted int he past, and SquareWear demos), AASaver (including the upcoming AASaver 2.0 I just blogged about earlier tonight). So it will be quite a show!

It has been fun to prepare the demos, and a lot of work too. Below are my sketches for two of the OpenSprinkler demos:

and some real gears to go with the two demos:

In terms of promotional materials, new this year I have made a banner and some business cards to be distributed at the table:

These were made in the last minute, so they are not as professionally looking as I wanted, but the essential information is there 🙂 Also, I will have lots of colorful info pages and pictures at the table.

Time to go to sleep and prepare for the trip tomorrow. Hope to see you at the Maker Faire OpenSprinkler booth!

Posted in Arduino, Maker Faire, Sprinkler Projects | Comments Off

New Development PCB in the Mail Today

May 16th, 2013 by ray

Yup, I opened my mail box and found the lovely purple envelope from OSHPark. What’s in it?

Ah ha, it’s the new AASaver 2.0 prototype PCB. I can’t help getting my hands on it, so I quickly assembled two. Here is what the assembled board looks like (without and with AA batteries):

AASaver 2.0 is sort of a ‘mega’ version of AASaver 1.0: like 1.0, it takes two AA batteries and serves dual functions as both an LED flashlight and breadboard power supply. But it can do much more. First of all, I’ve added a LiPo charger circuitry so that you can use two AA batteries to charge an external LiPo battery:

I’ve also added an SMT potentiometer (trimmer) to adjust the charge current (see the picture on the right above), anywhere from 20mA to 100mA. This is not a random addition — there is a good reason to have this feature, which you shall see in a minute.

Another BIG addition is the functionality to charge USB devices like cell phones. Yup, you heard it right: there is a built-in type A USB receptacle that allows you to plug in a USB charging cable to add juice to your phone, MP3 player etc.

So this is similar to Adafruit’s MintyBoost, except that there is a catch: on MintyBoost, you use a pair of fresh battery to charge the phone, but with AASaver the whole point is to harvest the remaining energy in used or old batteries. How does this affect anything? Well, used batteries typically cannot supply a high amount of current, so you can’t use them directly to charge the phone — it simply won’t provide enough current to charge. The trick is to dump the energy slowly into a LiPo battery, then charge the phone through the LiPo battery later! Essentially the LiPo battery serves as a ‘water bucket’, which accumulates charges slowly (like water drops), so that even used AA batteries can charge it; once the ‘water bucket’ has accumulated enough charges, it can dump the ‘water’ at much faster rate. This is the same idea as how solar chargers work: solar cells are too weak to charge phones directly, but you can build up the charges by leveraging a battery. Now you see why there is a built-in LiPo charger!

The picture below shows where the LiPo battery should be plugged in when you want to use it to charge USB devices. In sum, if you have a fresh pair of AA batteries, you can charge USB devices directly; otherwise you first charge the LiPo battery with a controllable charging current (20mA recommended), then use the LiPo to charge USB devices. The circuit of AASaver 2.0 accepts either AA or LiPo as the source of its boost converter, and directs the boosted 5V to either USB port, or LiPo charger, selectable through the ‘Target’ switch at the right-end of the board. On top of these, there is a separate switch for turning on the flashlight LEDs, and there are pin headers spaced appropriately to match a standard breadboard, so you can use it as a battery-based breadboard 5V power supply. As you can see, it has a load of new features to provide better and more flexible ways to save your AA batteries 🙂