I would like use USB on a Raspberry PI to control
6 (and possible more) Tic T825 controllers. What is the best wiring approach? Is there a way to daisy chain the controllers to the one that is USB connected? Or, do I need 6 USB connections? Or use a USB->Maestro type controller? Again, what do you think would be the best (most stable, least complicated) approach to physically connecting the controllers?
Note: the stepper motors do not need to be synchronized
or use precise timing.
In researching the topic, some suggestions included using other approaches beside USB, but the RPi voltage differences and RPi real-time timing support have me concerned, so I would like a āset and forgetā approach like USB to handle stepper motor position.
I moved your post to a more appropriate section of the forum.
If you do not want to use a USB hub with a separate USB cable for each Tic, you could consider a USB-to-IĀ²C adapter like this one. You can assign each Tic a unique device number using the Tic Control Center, then connect all of them to the same IĀ²C bus as shown in the āSetting up IĀ²C controlā section of the Tic userās guide, under the āControlling multiple Tics with IĀ²Cā heading.
Alternatively, you could use the Raspberry Piās IĀ²C interface directly. As described in that same section of the userās guide, the Tic considers an input value of 2.1 V on SCL or SDA to be high, so it will work with 3.3V signals. However, since Raspberry Pi computers do not have the clamping diodes mentioned there, you will need to disable the pull-up resistors on the Tic controllers and connect your own pull-ups to 3.3V instead.
Thank you. The USB->I2C adapter was exactly what I was looking for. The documentation for Tic I2C control mentions possibly needing pullups on SCL and SDA leads - I assume using the USB->I2C adapter listed I would only need to supply power to the VCC/GND leads (no pullup)?
The I2C adapter has built-in pull-up resistors on both SDA and SCL lines (up to VCC), and the Tic also has built-in pull-ups, so you should not need to add any external ones.
