martyndwheeler
Posts: 68
Joined: Thu Jul 05, 2012 3:57 pm
Location: UK
Contact: Website

L293D

Sun Jun 09, 2013 9:02 am

Hello,

I have an L293D chip trying to control a 3 V motor. I am trying to run this off the GPIO pins of the RPi. However, the 3.3 V coming out of the board is proving insufficient to trigger the logic on the L293D chip (I'm powering it off the 5 V rail from the RPi). Has anyone else experienced this and can anyone offer an alternative chip?

Thanks
Martyn

bigbudly
Posts: 2
Joined: Wed Jan 25, 2012 1:33 pm

Re: L293D

Sun Jun 09, 2013 10:10 am

I have been successfully driving these chips directly from the GPIO 3.3v output for quite a while with no problems. Like you I have been using the RPi +5V for the enable pins (1 and 9). I use a separate supply for the motor power supply pins, Vcc (pins 8 and 16).
Have you tested your L293 to make sure it is not the problem?

martyndwheeler
Posts: 68
Joined: Thu Jul 05, 2012 3:57 pm
Location: UK
Contact: Website

Re: L293D

Sun Jun 09, 2013 1:11 pm

I was driving the enable (pin1) with 3.3v. I have amplified my pwm signal to 5v using a transistor. It now works using 3.3v on pins 2&7 to control the direction.
Thanks for your help

martyndwheeler
Posts: 68
Joined: Thu Jul 05, 2012 3:57 pm
Location: UK
Contact: Website

Re: L293D

Sun Jun 09, 2013 1:16 pm

I can't see anything in the data sheet about needing anymore than 2.3 v on the logic inputs though

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