I have a project where I need to control multiple L289N bridges. L289N bridge requires HIGH input to be at least 2.25V+ Which according to documentation Photon should be able to drive. However my D0 to D7 pins output constant 1.35V on HIGH. Which is enough to trigger the L289N a bit (i hear a buzzin…

Then you obviously haven’t got the L289N GND connected to the Photon GND - that is electronics 101 tho’ You always need one common reference ground for all devices directly connected otherwise measuring/sensing voltages is impossible. Imagine measuring length with a tape measure where the end of t…

What is the amperage you’re trying to pull?

@Mjones Not completely sure I’m using the same L289N H-Bridge driver as in this tutorial: [image] Arduino Modules - L298N Dual H-Bridge Motor Controller Arduino Modules - L298N Dual H-Bridge Motor Controller: Quick and simple start guide for using and exploring an L298N Dual H-Bridge Mo…

Maximum allowed through all pins is 120mA, each pin is 25 max though. This is most likely your problem. [image] Particle IO maximum current Hardware @bruce_miranda , each photon pin can source/sink 25ma of current though the total package current rating is limited to 120ma…

@Mjones ok but how come only 1.35V is provided on the HIGH on D0-D7 pins ? Regardless if anything is connected. Should it not provide more ? When I measure it with nothing connected on the pin it provides 1.35V always which is odd.

What is your voltage on the 3.3v pin?

Are you sure they're working as outputs? Got some code? Measuring 1.35V with a DMM or scope? DMM could show an average of a floating value. D0-7 set to outputs using pinMode()? With a 1k resistor attached between output and ground, instead of the part, do you still measure 1.35V or do you see 3.3…

[image] superkool: but how come only 1.35V is provided on the HIGH on D0-D7 pins ? The output voltage would be 3.3V when you have no load or a load that wouldn't draw more than ~20mA. Once you overload the GPIO the voltage will drop and you are running the risk of damaging the output stage. …

@ian.c @ScruffR This is my code. I flashed the device with this code I set my multimeter clamps to the D0 & D7 pins. I see 1.35V for 10s than 0V for 10s and repeat. Never above am I missing something in code/configuration ? int d0 = D0; int d7 = D7; void setup() { pinMode(d0, OUTPUT); …

Have you got your Photon in a breadboard? Do you measure the same thing with the Photon bare of anything else (including no breadboard)? What do you measure on the 3v3 pin? Can you try some other pins? (you may already have fried D0 & D7)

@ScruffR This is my code now: int d0 = D0; int d1 = D1; int d2 = D2; int d3 = D3; int d4 = D4; int d5 = D5; int d6 = D6; int d7 = D7; void setup() { pinMode(d0, OUTPUT); pinMode(d1, OUTPUT); pinMode(d2, OUTPUT); pinMode(d3, OUTPUT); pinMode(d4, OUTPUT); pinMode(d5, OUTPUT);…

Photon. HIGH outputs only 1.35V

Hardware

Mjones May 3, 2020, 10:46pm 4

Maximum allowed through all pins is 120mA, each pin is 25 max though. This is most likely your problem.

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Photon. HIGH outputs only 1.35V

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