My code for controlling the steering circuit is running in Jetson Orin. I am getting PWM & Direction as output from I/O pins on Orin. When checked on the Oscilloscope & DMM, I am seeing changes in PWM.
Now, when i am using H-bridge circuit, the steering motor is not responding to change in PWM or Direction. But earlier when i was using other hardware, which gave 5V on I/O, the steering motor was working fine.
So, I need to confirm a way through which I can shift 3.3V from Orin to 5V.
Hi, I think what you need is a 3v to 5v level shift.
There is the 74LVC-T line of level shifters - available from NXP and TI:
Hi, I am working with Arpit who originally posted the query.
The Jetson AGX Orin is supposed to drive a 30A 5V-30V motor driver circuit, which was previously driven by a MicroAutoBox-2
The motor driver circuit has the following inputs: 1) 12V power supply 2) PWM 3) Direction 4) Ground
The 12V power supply was provided by a Regulated Power Supply the Ground is internally connected to the negative of this power supply.
The MicroAutobox provided the PWM and DIR to drive this circuit at a 5V level.
The AGX Orin is supposed to provide the PWM and DIR instead.
We were able to generate PWM which ranges from 0-3.3V at 18kHz. The Direction pin is just a HIGH and LOW state (3.3V/0V). The same was observed on an oscilloscope.
However when connected to the motor driver circuit we could not observe any change in the output of the motor driver circuit, at any PWM the output from the driver circuit is always 12V.
We suspect that maybe since the circuit was previously given a 5V input and the Orin PWM pin can only generate a max 3.3V output our driver circuit is not working properly.
Hence the discussion on level shifting.
Even if we use the level shifter suggested above the IC requires to be connected to 2 systems supplying a Vcc of 1.8-5V, in our case System 1 can be Orin which generates 3.3V but System 2 is the driver circuit which provides 12V and will be unsuitable for any level shifter IC.
So we are unsure how we will use a level shifter in case of our system arrangement. Also suggestions from Hardware side our welcome!
If the motor driver worked with the MicroAutoBox with 5V levels, then it should work with an Orin and an 74LVC2T45.
The Orin 40 pin GPIO header provides 5V as well. It doen’t really matter where the 5V is coming from.
Use VCCA (Pin 1)=3.3V from Orin.
A1 and A2 (Pin 2 and 3) to Orin GPIO.
GND (Pin 4) to Orin GND and to Motor driver Ground
DIR (Pin 5) to VCCA (Pin1)
B1 and B2 (Pin 7 and 7) to Motor driver.
Use VCCB (Pin 8)=5V
Use 100nF X7R between VCCA and GND and VCCB and GND.
The Level shifter can drive ±24mA. Should be enough.
Thanks Frank!
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