How many times did you wanted to test cable you’ve just crimped? Just to find out did you put right wire on best retail pharmacy viagra price right place, especially if you don’t see very well, or you are color blind.
Guided by this idea i decided to make simple cable tester, which checks only connection between wires of RJ45 cable, no fancy “remote” tests or measuring distance to short / open wires; just plain simple resistive test.
There are many different schematics available on this subject on the internet, but we are living in 21. century, anything less then some kind of graphical display for showing test results is unacceptable. So i decided to viagra advertisements put on PCB two RJ45 connectors, 128 x 96 pixel graphic display, two LEDs and two buttons which aren’t used in current firmware. Since we have graphical display it would be shame not to have enough flash memory for graphical resources, so ATmega 128 seemed like decent choice. Although current firmware uses less then 6% of total flash memory, cialis 3 pills free coupon ATmega128 is the only controller which i had on the stock at the time with more than 20 GPIO pins and it system clock goes up to 16 MHz which is more then enough to drive graphic display.
So this is how it works: after turning it on, splash screen is shown on display, after five seconds device is ready (actually, device is ready 200 mS after switching it on, but i’ve put 5 seconds delay because splash screen looks neat ). As You can see on schematic, cialis softtabs online fast shipping every RJ45 connector is connected to its own port.
All pins of port “A” are set to logical 1; (5V) and on other side port (B) state are checked 100 times per second for any change, when change is detected controller takes eight measurements which consists of putting every pin of port “A” to logic 1 one pin at a time and storing content of PINB register to RAM. After measurements are taken, result “array” are compared by “cable database” data table which consist of viagra 100mg sildenafil citrate pfizer labs six known UTP cable types. Beside common patch and cross cables i found some drawings of ATM, T1, Token-ring… on internet, must admit i never heard for them before.
After comparisons results are shown on display, first which wire on port “A” is connected on which wire on port “B”, second PASS or FAIL is shown and below that description string; “Cross”, “Straight-thru”, “ATM”……. FAIL is shown when there are no measured array found in cable database data or some wire(s) is(are) not connected from port “A” to port “B”
PCB is double-sided, cialis and blood pressure medication most of components are SMD type to reduce PCB size.
On one of the snapshots below You can see error; cable pinout is cross, but description string shows “patch”, this is because i took pictures during firmware development, also maybe You’ve noticed that PCB layout isn’t same on CAD screenshot and picture of actual PCB, this one is due to some error during initial schematic design, which i fixed in latest revision. At that time i designed some stuff with ARM in same time, and i thought on ARM GPIO…. it’s very easy to viagra 100mg tablet 4 pack get confused (ARM – AVR… You see….)
Device is programmed via JTAG port which is great benefit of ATmega128 controller. You can find fuse bits settings on one of screenshots in gallery bellow. Also You can use ISP, but You’ll have to make some adapter. It’s not so difficult since most of buy viagra pay with paypal ISP pins are available on port “A”, except reset an power supply (+5V and GND).
Firmware: version v0.1
Gerber: version v0.3