All posts in HAM Radio/Hardware Hacking http://www.binrev.com/forums/index.php Fri, 12 Mar 2010 15:44:37 +0000 15 http://www.binrev.com/forums/index.php/topic/43152-microwave-reciever/ can anyone post a good tutorial on how to make a 2.4ghz microwave reviever, and how to use it? Fri, 12 Mar 2010 15:44:37 +0000 http://www.binrev.com/forums/index.php/topic/43152-microwave-reciever/ http://www.binrev.com/forums/index.php/topic/43141-gps-jamming/
I read some documentation I could find on GPS devices and the Pcode and C/A data are carried on 2 frequencies called the L1 and L2 bands at 1575.42 MHz and 1227.60 MHz. Would I need to broadcast something else on these frequencies to confuse the device? and if so would this be done with a crystal oscillator?

Is this even possible?]]> Wed, 10 Mar 2010 00:09:42 +0000 http://www.binrev.com/forums/index.php/topic/43141-gps-jamming/ http://www.binrev.com/forums/index.php/topic/43097-hacking-an-itrip/
i'd like to modify this belkin itrip type thing to transmit on frequencies other than the ones it allows for (88.1, 88.3, 88.5, 88.7) i'd like to transmit on frequencies between 92 and 100.

i opened the thing up and it has this chip doing the rf transmission, it's this: bh1417f

from the datasheet it looks like i can transmit on different frequencies (87.7-88.9 & 106.7-107.9) by manually setting pins on the chip but it doesn't say anything about transmitting between those 2 ranges, BUT digikey tells me that frequency is 76MHz ~ 90MHz, 87.5MHz ~ 108MHz

now am i completely restricted by the chip? or are there certain things i could do to modify the output like changing the crystal slightly or something like that? am i headed in the right direction or would it be way easier to learn how a fm transmitter works and build one from scratch?

thanks!]]> Wed, 03 Mar 2010 15:25:28 +0000 http://www.binrev.com/forums/index.php/topic/43097-hacking-an-itrip/ http://www.binrev.com/forums/index.php/topic/43083-cromemco-z-2-zpu-card-up-and-running/
I decided to skip the power supply rebuild, and use the Wunderbuss board with a bench supply, since it's small enough to keep on my desk and work on. It had a cut track in the data bus, and had part of its active termination circuitry removed -- presumably it failed first when the machine's diodes shorted and put AC on the bus. The last of the parts for the terminator came in last week, so I finished repairing it.

The next step was getting the ZPU card working. I've played around with Z-80's before, as well as the 8085 (they both run binary-compatible 8080 code). I found out the clock wasn't making it to the system bus, and that the signal on the Z-80's clock line was really ugly. Turns out that the two 7474 D-type flip-flops used in the speed selector (you can run a ZPU board at 2 or 4 MHz) was dead, and a section of the 7404 inverter in the crystal oscillator circuit was dead. After replacing these, and replacing the 74367 bus drivers someone had scavenged from the board, it appeared to be running.

The next step was in building a "HALT card" -- a S-100 board capable of delivering a HALT instruction to the Z-80's data bus. The S-100 standard provides a line that indicates the processor is halted, so I attached an LED to it through a 2N2222A transistor. Usually, you test for halt with an EPROM containing nothing but HALT instructions -- 0x76 at every location. Since I didn't have an EPROM board, I decided to hard-wire a DIP switch with pullup resistors to the data bus. That way, you could set 0x76 by hand and it'd appear at every location in memory. On reset, the HALT light lit:



Next, I added buffers for the Data In and Address buses -- just a bunch of 74ACT245 buffers. These feed address data into a 2716 EPROM and DL-2416 ASCII character display. There's some decode logic that selects the 2716 on memory read requests from the data bus, and selects the display on I/O writes. Since the memory map is the same as the one I used in my 8085 project, I was able to use the same test code to write characters to the display. The PDSP-1881 used in the 8085 board is addressed in reverse from the DL-2416, so "HELO" appears as "OLEH" -- still shows that the ZPU is reading and writing to memory and I/O just fine! There's a HALT at the end of the test program, so the HALT light is lit as well.



I'm working on adding serial I/O to the board with an Intel 8251 programmable serial controller. That will let me exercise the RAM on the 64K RAM board, once I get that working (I haven't tested it yet). I've got a Cromemco 4FDC controller card as well, which provides a serial terminal, floppy controller, and ROM monitor. If I can get it all working, the Z-2 and an old Heathkit H19 terminal will probably come with me to the Next HOPE, so that people can play around with it!]]> Sun, 28 Feb 2010 21:02:31 +0000 http://www.binrev.com/forums/index.php/topic/43083-cromemco-z-2-zpu-card-up-and-running/ http://www.binrev.com/forums/index.php/topic/42961-building-an-8085-based-computer/
Recently, though, I've found a few situations in which I'd like to have a microcontroller system with a true address and data bus, rather than implementing them through the larger PICs' output ports. I decided it was finally time to put together a basic 8085 system, since I'd now accumulated many 8085 CPUs, plenty of static RAM, and had acquired my own EPROM burner. This is the result:


I built my prototype for the project on a Vero project board, which contains traces oriented for DIP ICs, as well as power and ground planes. I started off with just the 8085, a 74LS373 8-bit latch for the multiplexed address bus, a 2716 2k x 8 EPROM, a 2 MHz crystal and some decoupling capacitors. I later added the small, red TIL311 hex display, and a 74LS04 hex inverter to supply its internal latch with a signal of correct polarity. The EPROM was wired directly to the data and address buses, with its Chip Enable tied to the Read output of the CPU, since there were no other memory devices present. The TIL311 was wired directly to the low 4 bits of the data bus, with its noninverting Latch Enable fed from the CPU's inverted Write line, through one of the inverters in the 74LS04. I wrote a short assembly program to output 0x0A on output port #0 (any port would work, as the TIL311 responded to any write from the CPU). The program was assembled using GNUSim8085 (an open-source 8085 assembler and simulator), tested, then the hex dump was manually entered into my Intel iUP-201 PROM programmer, which has a keyboard for the manual entry of hex data into a PROM. After fixing two swapped address lines, the program worked fine, and displayed "A" on the TIL311.

The next step was to add some RAM, for use as the 8085's stack, and for general storage of variables. I chose two uPD-2114 RAMs, which are 1k x 4 static RAMs -- you parallel two for 1k x 8. Since there was going to be real RAM and ROM present, it was necessary to come up with select logic to choose the EPROM or the RAM when memory accesses were performed, or the TIL311 when IO accesses happened. The 8085 provides IO/M, RD, and WR status lines, with M, RD, and WR being inverted (IO/M is one line, with 1 = IO access, and 0 = Memory access). The select logic was composed of inverters and NAND gates, from the 74LS04 and 74LS08 ICs. During this modification, I decided to add a PDSP-1881 8-character LED display for ASCII output. This was added to be activated on output ports 0-7 (one port for each character). Finally, I wrote an assembly to push "HELO" onto the system stack, then pop each character off and display it on an incremented output port. After correcting a timing error (the PSDP-1881 wasn't syncing with the 8085's clock), "HELO" appeared on the display after reset:


Here's a shot of the point-to-point wiring on the back of the board. It's 30-gauge Kynar wrapping wire:



I'll probably keep this board as-is for future embedded projects, but I plan on building a more complete system using an Augat wire-wrap board, since the point-to-point hand wiring is somewhat tedious. I've got an electric wire wrap gun for this purpose, and several different lengths of precut wrapping wire for this purpose. I'll probably add either an HD44780-based LCD or a serial UART next, with the intent of writing a small monitor program for the system. Eventually, I'd like to be able to load CP/M from ROM or perhaps floppy disk on the system.

If anyone is interested, I can post scans of my schematics, notes, and assembly code for this project. I've also got a pile of extra components, if anyone would like to build an 8085 system similar to this one. If one were to use the same memory map, code should be interchangeable between systems. If you'd like to build something like this, but lack a PROM burner, I could post my schematic for a manual programmer I built several years ago: you manually set the address and data bits, then trigger a 555 timer to provide the programming voltage pulse to the EPROM without damaging it.]]> Sat, 30 Jan 2010 18:34:44 +0000 http://www.binrev.com/forums/index.php/topic/42961-building-an-8085-based-computer/ http://www.binrev.com/forums/index.php/topic/42756-who-needs-keys-anyway/ http://sites.google.com/site/vehicleremotestarterextender/

Why not just text your car instead? This is a pretty cool James Bond-esqe hack.]]> Tue, 19 Jan 2010 02:27:12 +0000 http://www.binrev.com/forums/index.php/topic/42756-who-needs-keys-anyway/ http://www.binrev.com/forums/index.php/topic/42590-direct-tv-h-cards/ Sun, 03 Jan 2010 00:28:09 +0000 http://www.binrev.com/forums/index.php/topic/42590-direct-tv-h-cards/ http://www.binrev.com/forums/index.php/topic/42543-good-books-on-electronicselectrical-engineering/
My ultimate goal is building circuit boards for SDR RF modulation/demodulation, and possibly some basic transmitters. But like I said, anything that covers the basics rather well is ideal.]]> Thu, 24 Dec 2009 07:09:46 +0000 http://www.binrev.com/forums/index.php/topic/42543-good-books-on-electronicselectrical-engineering/ http://www.binrev.com/forums/index.php/topic/42513-headphonez/

edit: im posting pictures of the real ones tomorrow when i can turn my lights on and w.e.]]> Thu, 17 Dec 2009 07:48:12 +0000 http://www.binrev.com/forums/index.php/topic/42513-headphonez/ http://www.binrev.com/forums/index.php/topic/42489-seeking-expert-advice/
What would you recommend?


Business & marine radios?

http://www.radioshack.com/family/index.jsp?numProdsPerPage=60&x=7&y=11&categoryId=2032074& pg=1&retainProdsInSession=1

CB & Ham radios?

http://www.radioshack.com/family/index.jsp?numProdsPerPage=60&x=19&y=13&categoryId=2032070& pg=1&retainProdsInSession=1

Scanners?

http://www.radioshack.com/family/index.jsp?numProdsPerPage=60&x=19&y=9&categoryId=2032072& pg=1&retainProdsInSession=1


Any suggestions?

& Is there a site better (stock/pricing) than Radioshack for buying radio devices?]]> Sun, 13 Dec 2009 23:30:00 +0000 http://www.binrev.com/forums/index.php/topic/42489-seeking-expert-advice/ http://www.binrev.com/forums/index.php/topic/42469-blackberry-how-to-do-things/



I have a BlackBerry Curve 8330. I don't know if all Black Berrys will let you do this but I think they will.

First off, I'll start with the Documents To Go Standard Edition app. By default, it won't let you create Word documents nor can you delete them off the phone directly - for these features, they want a user to buy the Premium Edition of Documents To Go for $70. But is this really so? Nope. Here's how to create and delete Word documents anyway :

To create one on your phone :

-first, on your computer open Word and then hit "Save as". Yes - save a blank Word.
-2nd, transfer this blank Word onto your phone and name it something easy to recall so you'll know to never delete this one (this will serve as the starting point when you want to create a new Word document).
-3rd, now you have a blank Word on your phone. What to do now, you ask? It works this way : When you wish to create a new Word, just type/paste your text into this black Word you saved - when done with this part, you chose "Save as" (in the document itself) and give the new document whatever name you want then hit "Save" in the new little window that's popped up.

What the above steps do is it allows you to now create a new Word whenever you wish to using the blank Word you have. You'll notice that after you do this, the Black Berry always keeps a copy of the blank Word you have BUT also saves the new document as a separate file.

So much for needing their Premium version which costs $70.


Now, how to delete any Word off the berry :

1-go to your Media icon and open it (yes, the one where you'd play music, videos, etc).
2-now click the menu key and in the menu that appears choose "Explore".
3-now choose "Media Card".
4-now choose the "BlackBerry" folder and open it.
5-now go down to "documents" and open this.
6-now you'll see all your documents here. Highlight the document you want to delete, then hit the menu key and choose "Delete" and click this. Viola! The document you highlighted is now DELETED.

So much for needing the Premium Edition to do this.

In fact, using the steps above (steps 1-6), you can also create new folders for your documents here as well, and subfolders if you wish to. Personally, I created a folder called "my shit" which resides where the main ones are located, and here I place "music videos" (as one folder), "movies" (another folder), etc. This is a great help to organize my shit (pun not intended...lol).]]> Mon, 07 Dec 2009 17:20:26 +0000 http://www.binrev.com/forums/index.php/topic/42469-blackberry-how-to-do-things/ http://www.binrev.com/forums/index.php/topic/42426-part-15-hurts-my-head/
lost]]> Sat, 28 Nov 2009 20:42:50 +0000 http://www.binrev.com/forums/index.php/topic/42426-part-15-hurts-my-head/ http://www.binrev.com/forums/index.php/topic/41774-80211abgn-serial-module/ Basically I'm just looking for a stand alone, embedded wireless 802.11a/b/g/n serial module.

http://www.sparkfun.com/datasheets/Wireless/WiFi/rn-131G-ds.pdf]]> Fri, 14 Aug 2009 15:59:54 +0000 http://www.binrev.com/forums/index.php/topic/41774-80211abgn-serial-module/ http://www.binrev.com/forums/index.php/topic/41688-digital-power-meters/
Magnets maybe?]]> Fri, 24 Jul 2009 02:41:29 +0000 http://www.binrev.com/forums/index.php/topic/41688-digital-power-meters/ http://www.binrev.com/forums/index.php/topic/41670-using-camera-pantilt-head-as-azel-rotor/
thanks,
lostbaka]]> Wed, 22 Jul 2009 04:26:25 +0000 http://www.binrev.com/forums/index.php/topic/41670-using-camera-pantilt-head-as-azel-rotor/