Hello,
I have a shield that has a piezo “trigger” connected to an LED and then to RX on the Arduino. On every other board tried this works fine. I flick the piezo, the LED on the shield lights up, the LED on the Arduino RX lights up and the signal is received. I tried Arduino Leonardo, Arduino 101, Adafruit Metro M0 and Sparkfun Redboard Turbo and they all work fine.
When I tried a Sparkfun Redboard or a Sparkfun Blackboard(USB-C), the LED on the shield lights up and never turns off. The piezo “trigger” is never seen. The RX LED on the Arduino is not lit up.
Is there something different about RX on Redboard?
Please help,
Jason
Hi Jason.
The BlackBoard and RedBoard both use a different USB to serial chip than the other boards you’ve tried and I suspect your piezo may be damaging the TX pin on the USB to serial chip. (Arduino’s RX pin connects to the USB->serial chips TX pin)
It looks like the USB to serial chip we use on these boards is not quite as hardy as the others. You might try using a different pin than 0 or 1 on these boards to connect your piezo too.
Hmm, the Lagmeter shield PCB is designed that way. I don’t want to redesign it. Does having it work this way seem like a bad idea?
http://mjolnir.lille.inria.fr/turbotouc … UIST17.php
I will have to move to a different Arduino implementation.
Thanks,
Jason
OK I think I see the issue.
It looks like you need a board that is capable of becoming a USB HID device and the RedBoard and BlackBoard each have a processor on them that don’t have that capability. You’re going to want to avoid any board that has a USB to serial converter chip on board, those only show up to your computer as a serial device and not a USB HID device. (keyboard, mouse, game controller)
The Leonardo is probably your best bet since it can accept a shield and has USB capability built into the processor but if you can’t find that, the RedBoard Turbo would work as well. You’re looking for an Arduino board that has a 32U4 or SAMD21 processor on board. Either of those can become a HID device. (The Due has a different chip, but it has USB capability as well.)
Just in case you are still listening. What board do you recommend with the follow project goals:
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Would like to be able to run off just the barrel power with or without USB connected
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Need to be able to power a 5v servo that might have a little load on it (USB power is probably not enough)
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Need to be able to have an Adafruit MotorShield V2 on it running a couple of either 12v or 6v solenoids
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Need to have the Lagmeter shield on top of that
It seem like the Leonardo is my only option? I like the RedBoard Turbo, but things (processor/servos) look to be powered by USB and not the barrel connector.
Even with a Leonardo, I seem to have power bleeding through. I am going to try using two different boards, one for motor/servo control and one for latency measurement.
Since you’re talking about using boards we don’t have access too, I really can’t give a recommendation. It would be a good idea to split the functions up onto separate boards, if nothing else you don’t need to worry about pin conflicts and it would also make troubleshooting and code easier.
If I want to use the Redboard Turbo, how do I power servos? It seems like 5v only comes from USB and not barrel?
The barrel jack will power the board when you connect a power supply too it that supplies 5 volts or more. You can connect your servos to the VIN pin to power them from the barrel jack.
Don’t apply more than 6.5 volts to the barrel jack or you risk damage to your servos and the board.
Hmm, when I pull USB, with a 6v barrel connected, the code stops running.
If your code is trying to do something via USB and the USB isn’t connected to a computer, the code can stop because it’s waiting for your computer to respond.
Try the Blink sketch on the board, that should work regardless if the board is connected to USB or the barrel jack.
