my 1602 lcd keypad shield have "D1 ROBOT" markings. when you say "visually inspecting" it, does it translate to my shield and/or uno board getting fried?i let it run for more than 30 minutes already using analogWrite and it appears okay to me.i'm into software and noob in arduino
Backlight Arduino, Arduino, Arduino, LCD only Arduino, brightness LCD shield, LCD sheild No LCD shield No Arduino, Modified shied LCD No LCD No LCD No LCD sheild LCDFull 79mA 58mA - - 67mA Minimum 56mA 55.1mA - - 55mAOff 55mA 55mA 50mA 18.5mA 55mA
It amazing how many of these companies producing products don't have anyone with the technical expertise to know how to properly control a transistor. That seems like some pretty basic EE 101 knowledge.Even worse, doing it correctly does not affect the product's manufacturing costs.
For those wanting to test their shield for this problem, there is an easy test.Remove the shield from the arduino.Attach a wire to the D10 pin on the shield.Hook up ground and 5v to the corresponding shield pins.When power is turned on, the backlight should light.Ground the wire going to D10, the backlight should go off.Now for a simple test.Briefly (and I mean just a brief touch) connect the wire from D10 to Vcc.If the backlight, blinks when you touch the D10 wire to VCC, the shieldhas this issue.Do not set D10 to HIGH or use PWM on this shield unless you modify it.You can still control the backlight .First set D10 to LOW. (only need to that once)Then set the D10 to OUTPUT for off and INPUT for on.UPDATE: (2014-07-03)It is possible that there is still an issue even if the backlight doesn't "blink" duringthe above test. This could happen if the excess current draw isn't large enough to causea power issue for the backlight when doing the above test.It is possible that the current demand is still way beyond whatan AVR pin can safely supply.If this is the case, it might work a while but could end up frying the AVR over time.The best way to test for an issue is to actually measure the current on the D10 pin when it is being driven high.To do this, wire up the shield as described above but then measure the current between the D10 pin and VCC.Set your meter for current with + probe going to VCC and - probe going to the D10 pin on the shield.If you measure more than about 30ma, the backlight circuit has the issue.--- bill
Please, DO NOT do this stupid thing.Ive just burnt my lcd doing that omg. >.<