Orange Pi PC enable UART and use HC-12

[JohnQPublic]

I have OrangePi PC and I'd like to use HC-12  serial communications device.

I've successfully used it with RaspberryPi Zero with these instructions: http://dev.drun.net/2017/05/10/reading-hc-12-from-rpi-and-sending-to-domoticz/

I've found this useful info: https://forum.armbian.com/topic/1524-orange-pi-one-how-to-enable-uart/

 

I've connected the HC-12 to OPPC as follows:
VIN – Connect to  3.3 (PIN 2)

GND – Connect to  GND (PIN 6)

RX – Connect to (PIN 8, UART0_TXD)

TX – Connect to (PIN 10, UART0_RXD)
I've got Putty connected to OrangePi.

command "ls /dev/tty*" shows that I have /dev/ttyS0. I've tried to use it with Minicom: sudo minicom -b 9600 -o -D /dev/ttyS0

..to no avail. "uname -a" command shows "Linux orangepipc 3.4.113-sun8i #68 SMP PREEMPT Wed Sep 19 10:23:30 CEST 2018 armv7l armv7l armv7l GNU/Linux"

I opened the script.fex and it shows:

Quote

 

[uart0]
uart_used = 1
uart_port = 0
uart_type = 2
uart_tx = port:PA04<2><1><default><default>
uart_rx = port:PA05<2><1><default><default>

[uart1]
uart_used = 0
uart_port = 1
uart_type = 4
uart_tx = port:PG06<2><1><default><default>

 

...etc. I have no clue what these mean. The first useful info above mentions that I should modify them. 

What should I try next?

[martinayotte]

1 hour ago, JohnQPublic said:

RX – Connect to (PIN 8, UART0_TXD)

TX – Connect to (PIN 10, UART0_RXD)

If you look at OPiPC schematic, the Pin 8/10 are not UART0 but UART3, UART0 is connected on 3 pins Serial Debug header and used by kernel to output debug logs, so usable for your HC-12.

so in your script.fex, it should be present and "uart_used" should be 1 not 0 to activate it at next reboot.

1 hour ago, JohnQPublic said:

command "ls /dev/tty*" shows that I have /dev/ttyS0

UART3 should then be accessible as /dev/ttyS3 ...

[JohnQPublic]

Thank you for your reply.

Just to clarify. I'd rather not change script.bin in fear I mess something.

If I connect the RX and TX wires from the HC-12 to the 1+2 (GND, RX,TX) pins next to the HDMI connection (should ground be connected as well?) can I leave script.bin as it is?

Will it affect Putty?

 

If If have to change:
[uart1]
uart_used = 0
->
[uart1]
uart_used = 1
will I then have "/dev/ttyS1" available. Where shoul the HC-12 RX/TX wires then go?

[martinayotte]

8 hours ago, JohnQPublic said:

If I connect the RX and TX wires from the HC-12 to the 1+2 (GND, RX,TX) pins next to the HDMI connection (should ground be connected as well?) can I leave script.bin as it is?

But your HC-12 will receive a lot of junk since the kernel will output log there, especially at boot time. But you can try ... (be aware that this one is /dev/ttyS0)

 

8 hours ago, JohnQPublic said:

[uart1]
uart_used = 1

to the HDMI connection (should ground be connected as well?) can I leave script.bin as it is?

UART1 on OPiPC is pin38/40, but simply edit script.fex doesn't do anything until you recompile it as script.bin (make sure to backup original)

 

[JohnQPublic]

OK gathered enough courage to edit script.fex and compile it to script.bin and then reboot:

[uart3]
uart_used = 1
uart_port = 3
uart_type = 4
uart_tx = port:PA13<3><1><default><default>
uart_rx = port:PA14<3><1><default><default>

I have HC-12 RX wire going to Orangepipc pin 8 (PA13 TX)

and

HC-12 TX wire going to Orangepipc pin 10 (PA14 RX)

Now sending using /dev/ttyS3 appears to work, but receiving not. What could be the problem?

Other Orange Pi PC features seem towork fine (Putty, net etc)

[martinayotte]

On 11/21/2018 at 8:46 AM, JohnQPublic said:

Now sending using /dev/ttyS3 appears to work, but receiving not. What could be the problem?

I don't have much ideas : are you sure you didn't mix TX and RX ? If you pull down the "SET" pin, do you have answers when sending an AT command ?

 

[JohnQPublic]

I'll try to figure it out. I just want to thank you for you help.