[SOLVED] Impossible to solve my WMP problem

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maxic31
Posts: 20
Joined: Wed Mar 09, 2011 5:41 pm
Location: Toulouse

[SOLVED] Impossible to solve my WMP problem

Post by maxic31 »

Hi All !!!!
I'm completly desperate... I'm trying to solve my problem but I need your help: I don't anderstand.

I have a quadcopter with MultiWii v1.7 on Arduino Pro Mini.
-Probably WMP clone (ITG3205).
-4 mystery 12A.
-4 Tunigy 2204T with 7x3.5 propellers

I had problem with my WMP in normal mode (oversensitive). Then I made ziss_dm modification (direct connexion to Insense chipset): Cut two wires and connect directly SDA and SCL to arduino, No internal pull_up, ITG3200 device.

At this point all is OK. I'm fling very well !! Thank's Alex and all other for this project !

---------------------------------------------------------------------------

==> This morning, nothing work !!
Only Arduino LED blink blink blink... I think about the init of ITG3205.

Here you can see A12 arduino pin (VDD for WMP) waveform :
Image

Zoom on A12 :
Image

SCL signal :
Image

Zoom on SCL :
Image

The WMP with direct connexion :
Image

From the Configuration tool:
Image

I have tried to resold WMP, i have tried with other SW version: The same behaviour.

The blinking LED is WMP init error, right ? My WMP is dead ?

Thank's
Mx
Last edited by maxic31 on Mon May 23, 2011 1:11 pm, edited 1 time in total.

User avatar
maxic31
Posts: 20
Joined: Wed Mar 09, 2011 5:41 pm
Location: Toulouse

Re: Impossible to solve my WMP problem

Post by maxic31 »

Hey, another information, nothing on SDA: 0V

I'have tried to resolder all pin... no success :(

any idea ?

noobee
Posts: 66
Joined: Fri Feb 25, 2011 2:57 pm

Re: Impossible to solve my WMP problem

Post by noobee »

maxic31 wrote:Hey, another information, nothing on SDA: 0V

I'have tried to resolder all pin... no success :(

any idea ?


your wmp is likely to be broken.

the pulsing on d12 is probably due to the firmware trying to power cycle the wmp since it is not responsive.

foomatic
Posts: 17
Joined: Fri Jan 21, 2011 1:33 pm

Re: Impossible to solve my WMP problem

Post by foomatic »

maxic31 wrote:Hey, another information, nothing on SDA: 0V

Nothing on SDA? Sounds suspicious. Usually the controller (in this case the Atmel) states a request on the bus, connected devices see this request, check if they're meant and if they are, they respond.

SCL is the clock line, SDA is the data line. So what you're seeing on SCL indicates that data should be read from SDL.
Nothing happening on SDA means no request is going out (at least not completely, since a clock is supplied).

I can think of two possible explanations.
1. The Atmel doesn't supply data on SDA (which would mean it's broken or not properly programmed)
2. something pulls SDA to GND. May be a short on the wiring or a short inside on of the devices connected to the bus (which would also mean that the respective device is broken)

First I would check for shorts to GND on the SDA-line.
Second I would check if something happens on SDA when no WMP is connected.

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maxic31
Posts: 20
Joined: Wed Mar 09, 2011 5:41 pm
Location: Toulouse

Re: Impossible to solve my WMP problem

Post by maxic31 »

.
Thank you very much Foo !!!!


With your advice, i have investigated more deeply my I2C signal. I have removed my WMP and checked signal AND :) a problem appear on one pull up
Voltage = 0 on the resistor!!!
Image

I checked the pull up with my multimeter. Result : Resistor is dead, open circuit. I have replaced the dead resistor by a new one and :D :D

Then many thank's for your support. Today I'm flying, and it's so good !!

Last question: why my resistor was dead ? However there is no big current on this line :?:

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