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Post by coloradokb on May 26, 2017 12:52:36 GMT -8
Hi there, I see the Mux board when running the i2cdetect. Then I run the SDL_Pi_TCA9545/SDL_Pi_TCA9545.py test and it fails with an I/O and then no longer shows on the i2cdetect. Thoughts/Ideas???
sudo i2cdetect -y 1 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 70: -- -- -- 73 -- -- -- --
python2.7 SDL_Pi_TCA9545/testSDL_Pi_TCA9545.py
Test SDL_Pi_TCA9545 Version 1.0 - SwitchDoc Labs
Sample uses 0x73 Program Started at:2017-05-26 14:25:11
-----------BUS 0------------------- Traceback (most recent call last): File "SDL_Pi_TCA9545/testSDL_Pi_TCA9545.py", line 58, in <module> tca9545.write_control_register(TCA9545_CONFIG_BUS0) File "/home/pi/SDL_Pi_GroveWeatherPi/SDL_Pi_TCA9545/SDL_Pi_TCA9545.py", line 74, in write_control_register self._write(TCA9545_REG_CONFIG, config) File "/home/pi/SDL_Pi_GroveWeatherPi/SDL_Pi_TCA9545/SDL_Pi_TCA9545.py", line 52, in _write self._bus.write_byte_data(self._addr, register, data) IOError: [Errno 5] Input/output error
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Post by coloradokb on May 26, 2017 14:10:17 GMT -8
Actually, perhaps I need to take a step back as it's clear I'm not following along. I see the following information in other posts, "The most common mistake on wiring up the I2C mux is forgetting to connect the power pins for each bus (nothing works without it!)." I'm connecting the MUX to my Pi-to-Grove connector. I was under the impression I'd connect the Mux to the pi-grove-connector and the other Grove/I2C sensors onto the Mux. Do I need to order / use something not included by default with the I2C Mux board that is causing this issue and the reason none of the other connected sensors are seen? Sorry to be the total noob, but I'm pretty confused.
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Post by SDL on May 27, 2017 12:43:15 GMT -8
coloradokb, I'll bet you don't have the JP6 to JP7 wired up. That means there is no power to the four I2C buses and it won't work. The reason we did it this way is that some people like to mix 5V and 3.3V I2C buses and this is the way to do it. HOWEVER, this confuses new people more often than not so in the next production order for this board (later on this year), we are going to change this. We are connecting all the buses to whatever is being supplied from the computer (VDD) and then there is nothing to do. The board just works. We will provide a way for people to cut a trace on each muxed bus so they can supply a different voltage if they want. I have copied below you have to do (taken from the full specification) to make this work. Your data supports that you haven't hooked the power up! BP Sounds like you haven't hooked up power to the four I2C buses. The most common mistake on wiring up the I2C mux is forgetting to connect the power pins for each bus (nothing works without it!). From the spec: JP6 - I2C Auxiliary Power Pads These pads allow you to hook up power supplies for each of the 4 I2C Muxed busses. Depending on your design, you may be powering the I2C devices on each bus from another power supply. In that case, you would leave these pads empty. Otherwise, you connect the appropriate power supply for each bus. For example, if you want all busses at 3.3V and the host is a Raspberry Pi, you would hook up VCC (from the Pi @ 3.3V) . You can mix 3.3V and 5.0V I2C busses by connecting the pads on JP6 to their respective power supplies. JP7 - Auxiliary VCC connections These connectors are all tied to VCC on JP1 / 3, the VCC from the host interface (usually the Raspberry Pi or Arduino) Read more: forum.switchdoc.com/thread/234/read-i2c-mux-board#ixzz4iJVdpWyg
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Post by coloradokb on May 28, 2017 14:02:26 GMT -8
Thanks for your patience with my questions, BP. I think I'm getting it now. I will try wiring JP6 to JP7. A few questions...what type of cable would I use? I presume there's a standard 4-pin cable to use? Radio Shack/Amazon? Also, As I add additional IC2 sensors to the Mux board, do I need to do a similar additional cabling? Again, thanks for helping someone who's better at programming, than electrical/circuitry! EDIT: Actually, I did finally figured it out. Got some individual cables at Microcenter (not ideal) but they did the trick. It took me awhile to correctly coordinate where everything plugged in, but it seems to be working. I may post image of how it's setup as I have a few other questions. Anyway, thanks again, BP, for all your help!
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Post by SDL on May 30, 2017 9:18:50 GMT -8
Colorado,
Very glad to hear you got it running! Having a bunch of jumper wires is always good!
BP
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