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2025-03-30 12:51 am
Hi all,
I am using an IBT-2 to control a dc motor, I have seen the videos on the IBT-2 and using a microcontroller to control the motor, but I am wondering if I can control the motor without the need of a microcontroller.
This part of my project has to do with the manual side of things. I have two 1 relay modules connecting a foot pedal, that has 4 wires. One wire (green) is the chassis ground, black wire is powered with 12 v, then the red and white wire are for each side of the foot pedal. One of the relay modules has the red wire from the foot pedal ran into the IN on the relay and the other relay has the white wire. These relays are powered with 12v. The motor will be powered with 24v and 24v will be ran through the IBT-2 and out to the motor. I have VCC of the IBT 5v along with LEN and REN getting 5v. The RPWM and LPWM are connected to the NO on each relay module, but this configuration does not work. The COM on each relay module are grounded. If I disconnect the RPWM and LPWM and touch one end to 5v the motor kicks on and I can reverse it by touching the other end of the wire to the 5v as well.
I attached some images of the foot pedal and wiring diagram as well as the one relay module I am using. I have access to two relay modules if that helps, as well as a TKS-M8S motor driver that I wired up, but if I pressed the foot pedals with the TKS setup and two relay modules, the motor wouldn't stop spinning, I could only reverse the direction even if I lifted my foot off the pedal.
Any information helps, thank you.
2025-03-30 3:20 pm
Hi @leroy180,
I haven't any direct experience of the IBT-2, but I have just done a quick Google, to discover what it is. Maybe others can offer more insight. Please note, this means any comments will not have been 'tested' and are only first thoughts for you to ponder, not tested solutions.
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First impression:
My first impression is that the answer to your implied question "I am wondering if I can control the motor without the need of a microcontroller" is that it depends upon the required functionality.
If the system only requires the options on no power, full power 'left' and full power 'right', then it may be possible to only use a simple logic circuit. A microcontroller can conveniently provide such logic functionality, and in addition provide power/speed control by means of pulse width modulation (PWM). The microcontroller may also be able to use the current sense feedback from the IBT-2.
Note that a 'simple logic circuit', although vastly simpler than the internal logic of a microcontroller, may actually be more inconvenient for you to construct than using an 'off-the-shelf' microcontroller card!
I am confused about your need for a relay.
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Summarising my findings from your description and from the web:
- IBT-2 is a full H-bridge with some extra features.
- You have a double foot pedal, which apparently has a single-pole 13 Amp AC switch associated with each pedal. The internal wiring of the switch is not drawn, but the text suggests the two switches are both connected on one side to the black wire, and to the red wire for the left switch and the white side for the right switch. In addition, the pedal unit includes an additional circuit which ensures both switches appear open, if both pedals are pressed simultaneously.
- Essentially, there are three conditions :
- Left pedal only pressed: Red wire connects to black, white wire open
- Right pedal only pressed: White wire connects to black, red wire open
- Neither or both pedals pressed: white and red wires open
- As a "personal thought", I would not be surprised if a momentary 'unexpected' switch connection occurred when two pedals are actually being pressed ... it may not happen, but it is wise to check for it.
- You also discuss using a relay, which uses 12V, and a motor using 24V.
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I am not clear what functionality you actually require from the completed system, as this will affect the answer to your question. So a sentence or two describing this is needed.
This description should include why you have a relay in your circuit.
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Best wishes, Dave