I'm rather new to the Arduino world, but have been dealing with this problem for about a month and have pulled out sufficient hair so far.
Perhaps someone can explain to me what might be the problem.
I've uploaded the Standard Firmata on my Arduino Diecimila and also on my Atmega 168. The upload works well - meaning the program gets to the board and is stored there.
However. When I open up a patch in PureData to view the arduino (arduinotest.pd) and click on the analog inputs to turn them on I am
getting wild values that report there is a signal coming in on all the lines. This is regardless of whether anything is connected to my arduino....It will even report signals coming from the analog inputs 6
and 7 which my boards don't even have.
Can someone please point me in the right direction to solve this problem or perhaps give me some clues or answers as to why my boards would be reporting input on the analog ins when nothing is connected to them?
Try grounding the pins that you are trying to read from, they should report zero. Then try attaching them to the 5 volt, they should read 1023.
Analog pins which are not attached to anything will read floating values, this is because they are set to a very very low impedance, this means they pick up current easily.
In general you will usually know what pins you want to monitor, and your circuit will be either feeding them current or grounding them, so the floating issue doesn't matter.
Hi Justin, did you meant to say that the analog inputs are a relatively high impedance, I think they are something like 100k ohms. But your comment about not using values from floating inputs is good advice.
another test arduiYES can use is to write a simple sketch that does an analogRead on the relevant pin and sends this to the serial port. If the readings on the Arduino serial monitor still show 'wild' values, the problem is with the analog input readings. Otherwise, its the sketch or on the fermata/PD side.
hey guys, thanks a lot.
nice to finally learn my arduinos are functioning properly after all.
i'll see if i can try to save some of these mats of hair on the floor,
twist them into a costume, and throw an impromtu hallowino party.