Armbianer Posted January 25 Posted January 25 (edited) Hello. For some reason, UART1 does not work for transmission, only for reception. The transmitter pin itself is definitely working, I checked by switching this pin to output mode, and then switching it to a high/low logical level, everything works properly, the level on the Pin changes. How I check the UART itself: I installed picocom, shorted the TX and RX pins, and I’m trying to see what I’m sending. For UART2 this method works as it should, but UART1 only works for reception. I realized this when I opened the TX and RX, and was able to receive incoming data sent through the USB-UART converter. Edited January 25 by Armbianer 0 Quote
SteeMan Posted January 25 Posted January 25 Providing logs with armbianmonitor -u helps with troubleshooting and significantly raises chances that issue gets addressed. 0 Quote
Gunjan Gupta Posted January 25 Posted January 25 Thanks for reporting . Will take a look over the weekends and get back to you. 0 Quote
Gunjan Gupta Posted January 28 Posted January 28 Seems to work fine for me. root@orangepizero:~# picocom -b 115200 /dev/ttyS1 picocom v3.1 port is : /dev/ttyS1 flowcontrol : none baudrate is : 115200 parity is : none databits are : 8 stopbits are : 1 escape is : C-a local echo is : no noinit is : no noreset is : no hangup is : no nolock is : no send_cmd is : sz -vv receive_cmd is : rz -vv -E imap is : omap is : emap is : crcrlf,delbs, logfile is : none initstring : none exit_after is : not set exit is : no Type [C-a] [C-h] to see available commands Terminal ready ggggggggggggggggggggggggggggggggggggggggggggggggggggggg As the headers doesn't come preinstalled to the device, I will suggest you to check if they are soldered correctly. Also make sure you are using pin 8 and pin10 as given in the schematics. Thats 4th and 5th pin when counting from the end closest to the leds on the inner row of 26 pin headers. 0 Quote
Armbianer Posted January 29 Author Posted January 29 (edited) Very strange things. On my board, UART1 has errors at a speed of more than 1200. The higher the speed, the more errors. That is, when the port is opened at a speed of 1200, everything is fine, at 9600 the characters are unreadable, and at 115200 nothing is displayed at all. Here is an example of displaying the sequence 1234567890 5 times at 2000 baud: Spoiler user@orangepizero:~$ sudo picocom -b 2000 /dev/ttyS1 picocom v3.1 port is : /dev/ttyS1 flowcontrol : none baudrate is : 2000 parity is : none databits are : 8 stopbits are : 1 escape is : C-a local echo is : no noinit is : no noreset is : no hangup is : no nolock is : no send_cmd is : sz -vv receive_cmd is : rz -vv -E imap is : omap is : emap is : crcrlf,delbs, logfile is : none initstring : none exit_after is : not set exit is : no Type [C-a] [C-h] to see available commands Terminal ready 1▒▒▒▒6▒8▒▒1234▒6789▒▒234567890123456▒▒9▒▒23456789▒ That is, the problem is not that UART1 TX does not send anything, but that it sends data with errors, and nothing is displayed at a speed of 115200. I have a very slow SD card. Could this be a possible reason for this behavior? Edited January 29 by Armbianer 0 Quote
Gunjan Gupta Posted January 30 Posted January 30 13 hours ago, Armbianer said: That is, the problem is not that UART1 TX does not send anything, but that it sends data with errors, and nothing is displayed at a speed of 115200. On my board I don't have the headers soldered. I just held a male to male jumper cable in place and tested the same and it worked fine. Have you soldered the headers? I wondered if there is a short somewhere. Can you share the photos of the board from both front and back? 0 Quote
Armbianer Posted January 30 Author Posted January 30 https://ibb.co/0czybBH https://ibb.co/ZL6wYNb https://ibb.co/swq5HRC 0 Quote
Gunjan Gupta Posted January 30 Posted January 30 24 minutes ago, Armbianer said: https://ibb.co/0czybBH https://ibb.co/ZL6wYNb https://ibb.co/swq5HRC Those links are not reachable 0 Quote
Armbianer Posted January 31 Author Posted January 31 (edited) https://rapidshare.io/20Rr/IMG_20240130_101637.jpg https://rapidshare.io/20Rs/IMG_20240130_101714.jpg https://rapidshare.io/20Rt/IMG_20240130_101629.jpg https://i.postimg.cc/ZR4qnB4s/IMG-20240130-101629.jpg https://i.postimg.cc/j2kqMMNB/IMG-20240130-101637.jpg https://i.postimg.cc/sx2DPkBp/IMG-20240130-101714.jpg Edited January 31 by Armbianer 0 Quote
Gunjan Gupta Posted January 31 Posted January 31 5 hours ago, Armbianer said: https://i.postimg.cc/j2kqMMNB/IMG-20240130-101637.jpg There looks like some residue around the pins, may be thats the flux. But anyways try cleaning that with some alcohol 5 hours ago, Armbianer said: https://i.postimg.cc/sx2DPkBp/IMG-20240130-101714.jpg This photo makes it look like there is something shorting tx and rx pin. Looks like a jumper or something. Not sure if what I am seeing is just lighting or something is really there, If something is there, can you try removing the same. Never mind, I guess you placed it for loopback testing. 0 Quote
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