Mar 24
You want to transmit some data across a long distance on a dedicated private network; however, you don’t want to run it over wires, where it could length up to miles? If you have no idea of what types of tools you should use here, then you can consider this Xbee 900 rf!
With this Xbee 900 rf, it allows you to send data up to 15 miles (24 kilometers) without have to connect to any fussy wires at all. For your information, the Xbee 900 rf wireless module send data over the 900 MHz ISM band and enable the information to be sent over great distance.
The 900 modules can traverse up to 6 miles line-of-sight at up to 156 kbps. The boards are part of the hacker-favorite Xbee module series, and it makes it easy to connect these devices to a microcontroller.
For those that need to send private data between [...] [Via]
Uncategorized
Mar 24
USBtoparallel
This device was built using AVRUSB firmware developed by extern Objective Development.
Meanwhile, a very similar Release 1.6 exists.
This Low-Speed device violates following USB specification rules:
* Detachable cable (must be captive for Low-Speed)
* Output drivers with 5 V (must be 3.3 V, but USB is 5 V tolerant)
* No differential data input (only one line D- is sampled)
* No data clock regenration while receiving (only at packet start)
* No error detection of input data (OUT direction), no time for CRC16
* Data transfer using BULK pipes (not specified for low-speed, but works on Windows – for Linux there is an “Alternate Setting” with INTERRUPT pipes instead)
However, new to this firmware, following rules are accepted:
* Suspend detection and lowered suspend current (below 500 µA)
[Via]
Mar 23
Do you think it’s very fussy to deal with the LED, especially when you have to change the broken LED Signboard all by yourself? Well, you should stop complaining and start repairing it, as time is precious…
First thing first, you have to open the signboard and check the problems. To be honest, when you’re looking on the signboard like the below figure, you must be shocked and doubt if you can ever get it fixed.
The truth is many parallel series chains of LEDs are the only reasonable way to design something like this. It’s reasonable to make chains of three each blue and white LEDs, as is given the respective voltage a great drops.
After that, it’s time to start with the power connection for the signboard. Normally, most of the plugs are designed to make good mechanical contact when it’s sunk completely into the jack. Sometimes, the springiness of the [...] [Via]
Uncategorized
Mar 23
* R1-R4 = 220R
Atmega 128 is like other AVR microcontrollers. They are ISP - is in-system programmable. Earlier I wrote an article about AVR ISP programmer where 74HC244 buffer is used. Using buffer is safer for your AVR.
But what if you need 128 atmega programmer without any parts, then you can connect your microcontroller directly to LPT port or use protection resistors (220R) just in case. of course circuit works without resistors, but you put your LPT port at risk.
Read the rest of this entry »
