I suggest you check with multimeter on resistance setting, that the wires atually make connection from the connector actual pins to the actual pins of the desitinations. Update your wiring and or diagram to match exactly, as it is difficlut to help with mistakes on diagrams.chrney wrote:It is connected to pin 6, not 8, thats a mistake in the diagram.
I connected the four wires to the I2c-backboard, GND, VCC, and the two that started with S. Nothing to the 16 pins on the LCD itself.
I am not familiar with the breakout cable you are using, but it looks to me that 5V and 0V (2 and 6 respecively) make sense as to the pins they are connected to on the cable. The white wire does NOT look like it is connected to pin 1 or 17 actually looks more like pin 10. SDA and SCl are on adjacent pins but your cables are connected to it looks like 1 nd 5chrney wrote:http://i.imgur.com/u9psY.jpg
= updated drawing. Sorry for the confusion in the prior drawing.
= movie with actual wiring. I hope you can see anything. It was the best way of illustrating this. It's just like I have the wiring on the drawing above. It's 4.3 meg, the movie.
Still nothing, but when checking i2cdetect with parameter 1, it does not hang anymore. But I can still not find the device.
On resistance setting power off Pi, and check to pins on GPIO connector to your circuit to be sure you are connected correctly.chrney wrote:Hi Paul,
How do you mean, how do I check the things with the multimeter? I checked the VCC, SDA and SCL against GND on the display, they all show about 4.5V, likewise on the breadboard HL-side. Breadboard LV side it's 3.3V.
Well appears connected correctly.chrney wrote:Hi Paul,
at first, I'd like you to know that I really am very thankful for all the help!
The white wire was connected to pin 1, the SCL and SDA are connected to pin 5 and 3. I made a new video, where I removed all the unnecessary wiring on the Pi itself. Check it here:
Would you mind to check this once again?
Yes pull power off Pi you cannot do resistance tests with power in a circuit.chrney wrote:Sorry, I still don't get it - as I said, I am quite a noob here. So:
a) should I power off the Pi? That is, to pull the power cord? Not likely, but anyway, checking.
b) Where should I place the plus-"stick" of the multimeter,
c) where the minus-"stick"?
They look OK when used after level shifter.chrney wrote:http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0915954990
Suggests level converter either broken or bad connection. Flicker suggests other problem could be a loose connection or not being initialised.. Could also be a faulty display.chrney wrote:Without resistors = no change
SDA och SCL connected to GPIOs = display flickering, meassured 3.3v on the display's SDA and SCL - but, it finds the device on i2cdetect -y 0.
Probably can you write text to it ?chrney wrote:I tested the display the GPIO-way (connecting 12 out of 16 wires) - that worked just fine. So the display is good then, I guess?
Looks like working then my money is on level shifter or wiring problems, every additional connection or connection point is potential for problems, always keep number of connections to a minimumchrney wrote:Yes, yes i can.
You probaly have 4.7V on Pi and loss on the cables making it 4.5V.chrney wrote:How come that I always just get 4.5V? Should that not be 5V, straight through?
Alternatively You meter is not accurate or has poor lead connection.techpaul wrote:You probaly have 4.7V on Pi and loss on the cables making it 4.5V.chrney wrote:How come that I always just get 4.5V? Should that not be 5V, straight through?
Alternatively you have a a poor PSU only giving 4.5V, or a thin USB cable or the PSU dropping volts due to too large a loadfor the PSU, or a combination of all of the above.
Users browsing this forum: donjones and 7 guests