My batt icon shows the full 4 bars ("full") but power button is still red.
Thanks ahakman,
That explains some of the puzzle.
Yes, I was kind of expecting that when you plug the 703S via a USB cable it would show up on the Windows computer with a newly assigned COM port, similar to when you connect and Arduino or ESP32 device.
So I sacrifice an old USB cable and stripped it and connected the 2 USB data wires to the Multimeter Signal Generator Output Port. Having UART=ON, when I plug into the male end of the USB cable to Windows machine, it does not show as a COM port in Device Manager. But I did hear Device Manager give a Ding, like it recognized something (I could not easily find the change).
Things didn't work, its late, will try another day...
PS1: I have visions I might have to use old 9 pin RS-232 cable and hook up to old WinXP computer (that has the old serial ports)... Or maybe I can use a Serial Port to USB port cable... Please "Say it isn't so, Joe"
PS2: In Windows Device Manager if you do not see COM Ports, you might have to click View Menu > Show hidden devices.
PS1: I have visions I might have to use old 9 pin RS-232 cable and hook up to old WinXP computer (that has the old serial ports)... Or maybe I can use a Serial Port to USB port cable... Please "Say it isn't so, Joe"
The ZT-702S oscilloscope does not show the end of charging on the display. The battery icon does not change. How to determine that charging has ended?
When the DMM is fully charged
When the DMM is fully chargedHow long does it take to fully charge?
Yes, you need to use a TTL RS232 to USB adapter if your computer doesn't have native serial ports. The meter will be outputting raw TTL RS232 - you can't connect that directly to a USB cable - they're not the same protocol at all.
It needs to go.
meter --> ttl rs232 to usb adapter -> usb port on computer
Even if you have native serial ports, you'd probably need a level shifter - I'm guessing the meter is outputting 3.3V signals, and a real serial port is expecting +/- 12V. Maybe some modern serial ports work directly with TTL, but even if so, 3.3V might be too low for reliable communication.
Voltage:-23.211 mV
Voltage:0.0003 V
Resistance:0.L KOM
Resistance:002.15 OM
beep:. OM
beep:000.04 OM
Diode:. V
Diode:00.001 V
Electricity:0.0000 A
Yes, a TTL RS232 to USB adapter works just fine. The meter outputs a 3.0 volt signal as you can see from the scope capture.
Here's are some sample output lines, note that there is no <CR> nor <LF> marking the line ends this is my edit. The meter sends about 3 lines per second so the delay between records can be used as a break. Also, the output doesn't specify AC or DC, this seems to be an oversight. Finally current is called "electricity"!
I don't think I've ever seen a TTL usb to serial adapter have a 9 pin connector on them. Usually they have loose wires (flying leads), or raw solder pads that you solder your own wires to. Having a 9pin connector typically means it's a full RS232 voltage adapter, and NOT TTL.
You're probably getting garbled communications because 3V is not enough to reliably signal the USB to Serial adapter you have because it's not actually a TTL level adapter.
The settings will be 115200, 8, N, 1
No flow control
No handshaking
ASCII
and no delay (character delay is usually only for transmission - it introduces a slight delay between characters - it does nothing for reception)
Yes, a TTL RS232 to USB adapter works just fine. The meter outputs a 3.0 volt signal as you can see from the scope capture.
Here's are some sample output lines, note that there is no <CR> nor <LF> marking the line ends this is my edit. The meter sends about 3 lines per second so the delay between records can be used as a break. Also, the output doesn't specify AC or DC, this seems to be an oversight. Finally current is called "electricity"!
Katie/KWASS:
Could you please tell what exact Baud settings you used?
Baud Rate: 115200
Data bits: ??[5, 6, 7, or 8]
Parity: ?? [even, odd, none, mark, space]
Stop bits: ??[1, 1.5, or 2]
Flow control: ??[hardware, software, none, Xon / Xoff]
Handshaking: ??[none, XON/XOFF, RTS/CTS, DSR/DTR]
Language: ??[ASCII, utf-8, other]
Delay: ??[some serial communication programs have this...]
I know that standard setting is Parity=N, Data bits=8, Stop bit=1, Flow control=None, but not sure with this company Zoyi since no exact documentation. I'm not sure they even used standard settings...
I was able to use a USB to TTL RS232 9-pin adaptor, but in the serial output programs I use the message is always garbled. So some setting(s) is(are) wrong.
I don't think I've ever seen a TTL usb to serial adapter have a 9 pin connector on them. Usually they have loose wires (flying leads), or raw solder pads that you solder your own wires to. Having a 9pin connector typically means it's a full RS232 voltage adapter, and NOT TTL.
You're probably getting garbled communications because 3V is not enough to reliably signal the USB to Serial adapter you have because it's not actually a TTL level adapter.
The settings will be 115200, 8, N, 1
No flow control
No handshaking
ASCII
and no delay (character delay is usually only for transmission - it introduces a slight delay between characters - it does nothing for reception)
That's exactly what I used for settings. For hardware, I used something like this from Amazon. It only has RX, TX and GND so there's no way to mess up the handshaking options! https://www.amazon.com/DSD-TECH-3-5mm-Cable-Interface/dp/B07XXVF4RM
Did you cut off the 1/8" end and wire it to a USB-C male end? My 703 only has USB-C
Is there a 1/8" female to USB-C adapter made for just the serial lines?
Did you cut off the 1/8" end and wire it to a USB-C male end? My 703 only has USB-C
Is there a 1/8" female to USB-C adapter made for just the serial lines?
As noted earlier in this thread, the 703's UART communication occurs over the signal generator output. Not the USB-C port.