I’m really new to this stuff but I’m working on a school project and need some assistance.
I have the Dual G2 HPMD connected to my Raspberry Pi and I can use the RPi just fine with power connected through the driver.
However, I have a Glideforce GF23-120506-3-65 High-Speed LID Linear Actuator w/ Feedback, and I’m wondering how I go about connecting the three feedback wires to the driver?
Connecting the power cables to the driver is pretty straightforward and there is a photo showing the connection for the feedback wires on the Jrk G2 21 v3 in the product info, but I’m not sure which pin holes connectors are appropriate on this specific driver.
Unlike the Jrk G2 21v3 that you mentioned, the Dual G2 High-Power Motor Drivers for Raspberry Pi do not have any special support for reading or handling feedback such as the analog voltage from the potentiometer on the Glideforce actuators.
Generally, you could use your main controller to handle the processing of the feedback. However, the Raspberry Pi boards do not have a built-in ADC (analog-to-digital converter) and cannot read analog voltage signals directly. You might consider using an external ADC like this one from Adafruit.
Thank you for the response. I did get an ads1115 that seems to work with just the Pi using the command line:
$ sudo i2cdetect -y 1
However when the driver is connected and powering the Pi the unused GPIO pins don’t seem to supply the voltage required for the ADC board and I can’t seem to find any in depth documentation on the GPIO pins on the driver.
The open pins on the driver 4 and 17 which would normally supply 3.3V and 5V are only supplying 3.1V and 0V respectively.
Raspberry Pi pins 4 and 17 should be 5V and 3.3V, respectively (it looks like you have them mixed up).
In any case, could you clarify which Raspberry Pi you are using and how you are powering everything? Also, could you post some pictures of your setup that show all of your connections?
My mistake, I did mix up the pin and voltage specs.
The Raspberry Pi being used Model 4B+
A 12V Power supply is running into the power in ports on the driver.
And the photo here is showing how the motor and ADS1115 are connected…
Thank you for the additional information. Could you also post some close-up pictures of the underside of your G2 High-Power Motor Driver so I can inspect the soldering?
It is hard to tell for sure from your pictures, but it looks like a couple of your solder joints might be cold, particularly the one on pin 4. Could you also post some pictures showing the soldering on the screw terminal blocks for the power and motor pins?
Applying too much heat for too long can damage various parts of the board. In general, you should only need to heat each 0.1" pin for a second or two and should not linger too long on any of the joints. The larger pads for the power and motor pins, and the ground pads might need slightly longer since they are connected to larger planes.
The board was purchased pre-assembled however so I don’t suspect any issues with those especially since the motors and pi work fine, it’s just the voltages from the GPIO’s.
Also I’ve removed the GPIO pins that I had soldered in (except the ground pins) and checked the pads while the device was powered and I’m still not getting more than 3.3V out of pin 4. I also tested different ground pads to make sure it wasn’t an issue with soldering on the ground pins.
Sorry for the confusion and misunderstanding, but I finally see the mistake that both of us were overlooking! The pins you are connecting to are pins GPIO 4 and GPIO 17, not physical pins 4 and 17 on the header. The 5V and 3.3V outputs are not made available on the row of pins you were using, but you can get it by tapping into the top of the female header pins that connect directly to the Raspberry Pi. (Alternatively, you can get 5V from the VREG pin, but other than the Raspberry Pi header, there is no other access to the 3.3V output.)
Ok, that would make sense. I guess I’m a little confused about what the open row is for? Are those pin holes just regular open GPIOs and why is there still a 3.1-3.2V reading coming from pin hole 4?
That row gives access to the Raspberry Pi GPIO (general purpose input/ouput) pins, which operate at 3.3V; the main reason for breaking them out is to make it easier to remap the connections on the expansion board (e.g. to stack multiple expansion boards on top of each other).
So, it is normal for them to measure either 0V or 3.3V depending on what the Raspberry Pi is currently doing with that GPIO pin (they are pulled up or down by default which probably explains what you are seeing); however, they are logic signals and cannot source the same amount of current that the regulated 3.3V output pins can.
Awesome, that makes a lot more sense now. Thank you.
Just checked that VREG pad on the driver and measured 5V.
So If I wanted to connect my ADC board VCC to that pin that wouldn’t interfere with anything? I guess I should note that it would only be used for the motor sensor.
