I have a problem with the MMA7455 panel in ARC normally ARC connects fine but if I add the 7455 panel it locks up ARC on connecting to the EZ B board and I have to use Windows task manager to shut it down and start again. It has worked for me but only a couple of times
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It is a very sensitive piece of equipment and cable lengths are very important, if they aren't right then it simply wont work.
And the EZ-B V4 will hang and freeze up on any I2C error (the manufacturers of the main processor designed it that way).
Keep trimming back that length and retesting is pretty much the option here. As previously stated, mine were about 4 inches long when I was testing out the device on the EZ-B V3.
Hi are you using this as a G meter for your car?
If you have an Iphone you could try the sensor streamer app (was a free download from the apps store) that sends data straight to your PC and gives you an accelerometer for 3 axis. DJ added a panel to ARC for it.
@Winstn60 Actually I'm sorry to contradict you but shorter wires are better when dealing with I2C, due to lower line capacitance.
@julius I can see that you are using 3.3V from the ez-b going into the onboard 3.3V regulator, this might be dropping your voltage down far enough to make the sensor communication unstable. (Thanks for the photos, it definitely helps)
Resolved by Rich!
Hello there,
I'm struggling with that problem discussed here.
As soon i activate the MAA 7455 (connected with the i2c) Module in the software the EZ-Board and software freezes.
i really want to use the mma7455 but i cant see whats wrong. the length of the cables are about 7 inc.
any ideas ?
Is it connected to the EZ-B correctly?
It is a very sensitive piece of equipment and cable lengths are very important, if they aren't right then it simply wont work.
And the EZ-B V4 will hang and freeze up on any I2C error (the manufacturers of the main processor designed it that way).
Keep trimming back that length and retesting is pretty much the option here. As previously stated, mine were about 4 inches long when I was testing out the device on the EZ-B V3.
thanks for the fast response!
thats properly it !
i used different power connectors (3,3V and ground from the Ax row).
..now i have shorten the lines to about 2,5 inches but its still freezing the board.
should i use the power pin's of my used SDA/SCL port ?
@Julius are you using any pullup resistors from SDA and SCL to 3.3V? If not, toss in some 4.7-6.8kohm resistors to see if that'll help.
i tried this :
2x2 10k ohms in parallel.but nothing different than before. again ez board freezes as soon as i start the i2c maa7455 module in the software.
here is the set-up:
(red = 3.3 V, brown = ground, blue = SCL, green = SDA)
Hi are you using this as a G meter for your car? If you have an Iphone you could try the sensor streamer app (was a free download from the apps store) that sends data straight to your PC and gives you an accelerometer for 3 axis. DJ added a panel to ARC for it.
Otherwise try longer wires to the MMA7455
@Winstn60 Actually I'm sorry to contradict you but shorter wires are better when dealing with I2C, due to lower line capacitance.
@julius I can see that you are using 3.3V from the ez-b going into the onboard 3.3V regulator, this might be dropping your voltage down far enough to make the sensor communication unstable. (Thanks for the photos, it definitely helps)
Hi @Jeremie contradict away but as I posted 1 year ago I had to increase the wire length to get it to work go figure confused