Anyone Running with a New Raspberry Pi 3+?

[georgeioak]

I had one of the original OS boards and an old Pi that worked for many years. I started using the Pi for more than just OS so I swapped out the Pi for the newest 3+. Shortly after that I had problems running OS, the valves would all turn on as soon as I applied 24VAC.

I just purchased a new OS Pi board and connected it to my Pi 3+ and I can’t get it to activate any valves.

My setup is a bit unique. I have the Pi connected to the official 7″ LCD and touch screen which is in a case. I made a jumper cable to connect the Pi to the OS board.

I am using a USB 5-port charger (which supports 2.4A per port) and I have 1 USB cable powering the Pi and another for the LCD driver board.

When I issue a gpio readall I see that SDA is high but SCL is low but since the Pi has pull-ups I would expect both SDA and SCL to be high.

When I issue a i2cdetect -y 1 it does not find any I2C devices which is odd since the OS board has the DS1307 RTC and the PCF8591. I’m guessing that at this point it doesn’t find those 2 I2C devices because I’m seeing SCL low and something is holding it low.

I believe that the 7″ touchscreen is connected over I2C and that does work so I don’t think there’s a problem with my Raspberry Pi but at this point I guess anything is possible.

So if anyone is running with a new Pi would you mind checking what you get when you issue gpio readall and i2cdetect -y 1 I would really appreciate it.

[georgeioak]

I saw that I was running firmware 2.1.7 so I justed updated that to 2.1.8 but that didn’t help.

If I disconnect the OS board from the Pi and run gpio readall I can see that SCL goes high so it does appear that something on my new OS Board is pulling/holding SCL low.

Was I just unlucky and received a defective OS board?

[Ray]

What pins does the 7″ LCD use? It’s possible that it overlaps with pins OSPi uses and hence causes interference with valve actions. The pins that OSPi uses are documented in the user manual:
https://rayshobby.net/docs/ospi143+_manual.pdf
page 6.

[joshb]

I have the same exact issues as georgeioak except for I have no LCD. When the Pi is disconnected, SCL goes high, otherwise SCL is always low when connected.

It appears that write to the shift register are also not working, as outputs are either all 24V or 0V after disconnecting from power and rebooting.

Any thoughts?

[Ray]

I2c shouldn’t affect anything — the firmware doesn’t use I2C at all.

[Author]

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