Tonlaar
I’m trying to connect an Arduino Nano with the EZ-B v4 to offload some of the work. UART1 and UART2 work fine!
Problem is with UART0 (information is send but corrupted)
Connection:
Arduino GND to EZ-B v4 GND
Arduino RX connected to UART0 TX (first pin), D5 or D18
Attached to the Arduino is a 2x16 character LCD (I2C connection) to display (the serial information (also visible true the Serial Monitor) using a simple protocol; 0 (0x30) = clear LCD, 1 (0x31) = start at line 1, 2 (0x32) = start at line 2. All other information is just displayed.
All is fine and Information is displayed correctly when attached to pin D5 or D18.
When connected to the TX pin of UART0 information is sporadically send but corrupted. Touching the wire (on the outside!) changes the behavior of the characters received (more characters but still corrupted)??!!
Ooops I was tired and you’re correct Dave. I took a quick look and saw the three wires and didn’t pay attention before closing my eyes for a good night rest
Still, I can’t understand or imagine what could cause that for his setup.
Added an extra ground to the other side of the Nano (3 GND wires now), problem still exists.
The thing is, I can easily move the green wire between UART0, 1 and 2 and check how the transmission is going. AURT 1 and 2 always work fine so I would think Ground is fine.
The problem is only with UART0. Most of the time all characters are corrupted. With a bad connection of the TX wire you would expect that wiggling the wire would change the behavior. It does not.
It may or may not be related but almost every time I’m testing there is this message My battery is low. The only thing I’m doing right now is running this serial script. Nothing else connected.
I’m using a bench power supply at 7.4V. Increasing the voltage doesn’t help. Unplugging and re-initializing will most of the time fix it. Sometimes I need to restart a couple of times
These are the Connection Control settings I use
How come there’s a long list of countries in ubb code after each of your responses lol? We keep having to delete them
If the battery is low message, it’s because you’re under powering the ezb - look into the battery monitor in the ezb data sheet. You’ve jumped a few steps ahead
the min battery voltage is in the connection control, and can be hard coded in the web interface.
I don't know how this list is added. [url=https://synthiam.com/Community]
I was able to delete the extra lines
As stated, I added an extra ground to the other side of the Nano (3 GND wires now), problem still exists.
The thing is, I can easily move the green wire between UART0, 1 and 2 and check how the transmission is going. UART1 and 2 always work fine so I would think Ground is fine.
The problem is only with UART0. Most of the time all characters are corrupted. With a bad connection of the TX wire you would expect that wiggling the wire would change the behavior. It does not.
I just found out that when I unhook the mini scope (BitScope DSO connected to orange wire) no characters are received at all. Plugging the orange wire back in, UAET0 start immediately producing (mostly corrupted) characters again. It is as if the signal is pulled down a bit more so it can be recognized as a signal but not far enough to be recognized correctly
As always UAR1 and 2 are working fine with or without the oscilloscope being attached
Those are indeed symptoms of a bad ground - which I can't understand given your picture looks fine.
Oh, reviewing your picture... I noticed the Bitscope isn't connected correctly as it's missing the ground. So if it "works" with the Bitscope connected, i'm guessing it's a grounding issue still. I know it's not what you want to hear but it's the only thing i can think of with similar results that you're experiencing.
Is there a different GND pin on the arduino that you can use? Maybe that GND isn't connected correctly or something?
Also, i doubt that USB power on the arduino can power the display correctly AND the arduino. You should consider giving it adequate supply rather than USB. I suspect if you checked the +5 that's powering the display you'll find the voltage to be quite low when it's displaying data
What happens if you take GND off somewhere else on the EZ-B? Like a digital port GND pin or an ADC gnd pin?
Lastly, you "could" try putting a 4.7k resistor pulling the EZ-B's TX line to GND (down). Maybe there's a lot of capacitance in the arduino?
As you know, this is the simplest circuit you could come across. It's ridiculously simplified and shouldn't be this complicated so something is affecting the results - and all signs point to a ground, but i can't understand how if you're confident the grounds are solid
This might be a silly question and you may have already tried it, but have you tried another Nano. I’ve have some obscured faults with a couple of Nano’s, which i’ve put down to Static damage due to the way they were packed on delivery. Anyway just a thought!