Can this be implemented on a pair of Wixels?
PC USB <—> WIXEL1 USB <—> WIXEL1 RADIO <—> WIXEL2 RADIO <—> WIXEL2 UART0 <—> MC1 UART
Simultaneous copy of WIXEL2 UART0 RX to WIXEL2 UART1 TX
WIXEL2 UART1 TX-ONLY —> MC2 UART RX ONLY
See attached drawing
Thanks
Stefan
Hello,
Why do you need the MC1 and MC2 to be connected to separate UARTs? Why not just connect them both to UART1 TX? The only reason I can think of would be if you needed different baud rates.
-Paul
Or…if I am understanding you wrong, and you really want a connection between MC1 TX and MC2 RX, why not make that connection with a wire instead of forcing it to go through the Wixel? You can generally connect several RX pins to a single TX pin.
-Paul
Hi Paul,
I need bidirectional capability between the PC and MC1 and unidirectional from MC1 to MC2 to drive a display.
Baud rates can be the same. The only reason I asked about using 2 UARTs is that when I tried connecting the TX pin from MC1 to RX pin on MC2 and also to RX pin on my PC COM port, the PC stops receiving and MC2 recieves a garbled stream. Individually MC1 to PC or MC1 to MC2 works fine. I am no expert with serial interfaces so my hypothesis was maybe signal loss due to two deviced on the same pin.
Both MC1 and MC2 are RS-232 standard - and the PC was fitted with a USB to RS232 adapter.
regards,
Stefan
Hello,
The Wixel uses logic level (3.3V) serial, so you cannot connect it directly to RS-232. That means to get your signal to the Wixel, you are going to have to bring some kind of level shifter into the picture. Now your question essentially becomes: “Can I connect both a level shifter and MC2 to the TX line of MC1?” In general I would say yes, but it probably depends on the specifics, and it’s really beyond the scope of the help we can provide here (unless you use our serial adapter).
I would recommend paying attention to the input and output impedances of your various devices and checking as much as possible on an oscilloscope. Also, you should double-check that MC2 uses RS-232 levels, since your problems are similar to what might happen if you connected RS-232 directly to a 3.3V microcontroller like the Wixel.
-Paul
hi Paul.
Thanks - I’ve decided to give it a go with a pair of wixels and the Pololu 23201a Serial Adapter.
The MC1 and MC2 are a matched pair so i presume they would have matched the RS232 levels. I will use the serial adapter to interface the Wixel to the ECU.
In case I do come across a problem with the RS232 interface splicing MC1, MC2 and Wixel- my initial question - can I use the Wixel to re-transmit the RX signal from one UART to the TX signal of another?
Thanks for your help.
stefan
Hello,
In electronics, it’s not a good idea to “presume” anything, especially when stuff is not working. Make sure you are actually connecting an RS-232 output to an RS-232 input, and that you have ground, power, and whatever else you need connected.
As for your original question, you probably could do that, but it would involve learning Wixel programming, possibly at a deep level, and you would need another level converter to generate the RS-232 output. Overall, reprogramming things is not going to be worth the effort compared to just connecting wires.
-Paul
