I thought I'd share my latest project with everyone, an RS-485 Temperature Sensor. This project was my very first project using Eagle schematic capture and board layout software. Overall, the board design worked out 100%. There were only two (minor) problems with the board as manufactured; the hole size for the terminal block connectors, and the omission of the tNames layer (due to a CAM oversight.....). The board is fine otherwise, and is 100% functional!
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This design will be used as part of my home automation system to measure temperatures in various parts of the house. I already have the wiring in place for an extensive RS-485 network, so the installation of the individual sensors will be easy. I'm currently working on a wireless version for my hot tub, and for an unattached workshop/garage.
This design is based on the PIC 16F648A processor, the MAX485 RS-485 interface IC, and the TC77 integrated temp. sensor. Each board has a (software) programmable network address, and network biasing (if required).
The boards were made using the DorkBotPDX PCB service. To be honest, I'm not really all that wild about the purple soldermask from an aesthetic standpoint, or the gold finish from a soldering standpoint, but the delivery and price were unbeatable (like $7 USD per board!)
If anyone is interested, I'd be happy to provide the schematic and board files as well as the firmware and documentation.
In addition to being my first Eagle designed project, it was also my very first 'all surface mount' project. All told, I believe that this first effort was a resounding success!
I thought I'd start my own thread for the assembly of my PIC USB Backpack. I say 'sorta!' in the topic title because I don't plan to use this board with an LCD, but rather as the basis of a development platform to experiment with some USB code.
So far, my board is assembled, but it's not yet working. I loaded it with the bootloader and firmware for the PIC USB Backpack to test the board, but nothing happens when I plug it into my PC. I know what to expect because I also have an USB IR Toy that's working fine.
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I checked the board carefully with a microscope, and did not see any shorts. I also checked the board for shorts with a continuity tester and did not find any. At this point, the assembly looks good!
I'm programming the board with a CCS USB PIC progammer, and everything seems to go OK during the firmware upload, yet it's not working. I did note that the voltage on pin 14 (Vusb) is 0, so it does not appear that the internal 3.3V reg. is being enabled. That explains why there is no USB activity, but not why the lack of enable. I suspect some minor difference in my programmer may be the problem, and the chip is not being programmed correctly?
I added an LED to the board today but ran out of time to write a small program to test if I can get that to work. Unfortunately, this effort may have to wait a few weeks as I'm traveling to Vietnam on Thursday for a couple of weeks. Sigh! So many projects, so little time!
It seems like the PIC LCD Backpack is not destined for production? It just so happens that I've got an application for something like this, so I'm wondering if there might be any boards available for it? Failing that, are the Eagle schematic and board files going to be released? I saw a mention on the project wiki that they were available, but I didn't see them on the Google code page.
I'm a complete newbie in the world of protocol sniffing, so I have a few basic questions. I've got a wireless thermometer that uses a 433 MHz RF link to transmit data from a remote sensor to the base unit. I built a 433 MHz receiver to capture this data, but I don't know how to proceed decoding the protocol to extract the temperature data. I can capture the 'bits' that are transmitted using a scope, so I'm wondering if this would be a good application for the Bus Pirate? Specifically, how does one go about decoding a completely unknown protocol after the data is captured?
I've got my web platform on order, and I'm already formulating some ideas for putting it to work! First and foremost, I'm going to 'web enable' my home-brew home automation system. How cool would it be to check the hot tub temperature via the web (this is a measurement I'm already making and displaying locally at home)
Anyway, is there a good primer available for making a device like the web platform accessible to the outside world? I assume that a service like Dynamic DNS (or equivalent) is required for those of us with non-static IP's? How about router setups, port selection, etc., etc.?
I just noticed the new web platform picture on the home page has a (dreaded) 'red' wire across the FTDI USB chip. Was that a forgotten connection? Is the connection properly routed on the production (Seeed) boards?
Are there any of the V1 #twatch boards still available? I want to do some firmware development without worrying about the 100 cycle write limitation of the V2 boards!
I bought a #twatch because I thought the concept was pretty neat. It honestly is, but still I'm finding Twitter to be really, really lame..... My #twatch spends most of it's time displaying LCDSmartie data instead. Something that I think would be very useful would be a stand-alone weather display similar to the #twatch. I think a unit with a nice graphical LCD displaying WeatherBug (or similar) weather data would be cool. It could display both current weather conditions, as well as forecasted weather conditions. The user might select the operating area (by zip code) via a web interface, for example. The unit might be called WxWatch, or something like that. Just wondering if anyone else sees a need and would like to collaborate on this project? I've got the tools to do circuit board designs and write code, and I've got a bit of experince with GLCD's.....
Any chance to get a schematic in .pdf format or something else that's readable when enlarged? The .png file on the website is just not cutting it for this purpose. I don't use Eagle, and I'm trying to avoid having to install it just to get a readable schematic unless I absolutely have to!
I received my #twatch from Seeed Studios this morning. I got the version without the LCD because I have many 20X4 LCD's lying around from other projects..... Anyway, when I connect the unit to my network and to a wall wart power supply (7VDC), I never see the network configuration screen. Rather, I see a bunch of seemingly random static gibberish. I say 'seemingly random' because similar characters will appear when I cycle the power, but not exactly. I see things like:
I:6925.1.1 AK:2525500GTE16.25.1
NS:6925411
Interestingly, when I plug in the network cable, the display becomes animated, and more gibberish seems to scroll by. Some of it even appears readable, but I'm not sure (it may be my imagination). If I run Netscan and scan the IP addresses in the range of my network, the #twatch does appear with an IP address of 192.168.1.170. If I unplug the unit and scan again, this address goes away.
I'm wondering if I have some sort of mongrel firmware on my board? I'm not sure what else might be the explanation?
BTW, I installed a jumper to prevent the bootloader from running, but that did not change the situation!
