OrangePi 3G-IOT-A / 3G-IOT-B first steps - Page 1
Forum section: electronics / general

author: DavidAlfa
author_rank: Super Contributor
timestamp: July 26, 2023, 05:00:54 pm
content: So I got this board, had a lot of issues to get it working.After a lot of head scratching these were the steps taken:First of all, the official manual is wrong in many ways and omits crucial information.Ensure to read this great article by PuceBaboon:https://esp8266hints.wordpress.com/2023/04/21/orange-pi-3g-iot-a-info/After finally getting Debian flashed, I ran into several issues.It would always bootloop, no matter what I flashed.Code: no flash ID match, no DRAM info match !<ASSERT> mt_emi.c:line 1048 0PL fatal error...PL delay for Long Press Rebootpl pmic powerkey Release emergency download mode(timeout: 5s).mtk_arch_reset at pre-loader!Thinking it was defective I claimed and got my money back.Days later, I tried again.Accidentally powered the board without the serial adapter and it booted, how is that?Indeed, connecting TX caused the problem. A voltage level issue?Measured Tx and RX... 1.8V. Ah! For sure this will be a problem with a 3.3V adapter!This is not specified, anywhere. OrangePi support is utter crap.Well, made a simple fix using a diode, then everything started working, to my surprise it did just fine at 921Kbaud:The UART port shows all the debugging info on top of your shell and it's an absolute mess to work on.Just get Wifi working and switch to SSH!Default credentials are root:orangepiWifi wasn't working at all.I could see the wireless networks using nmcli, but adding the settings to/etc/network/interfacescompletely killed the wifi interface.I ended emptying that file and adding the wifi connection with nmcli:Code:nmcli con add con-name MyWifi ifname wlan0 type wifi ssid MyWifi ` `ip4 192.168.0.11/24 gw4 192.168.0.1nmcli con modify MyWifi wifi-sec.key-mgmt wpa-psknmcli con modify MyWifi wifi-sec.psk MyWifiPasswordnmcli connection up MyWifi(I removed the DNS steps as they didn't work)After this, I could finally ping the board and connect through SSH at port 22.Default SSH credentials are orangepi:orangepiLater on, although I could see the DNS withsystemd-resolve --status, I was still unable to ping the outside world.All I was getting wasTemporary Failure in Name Resolutionerror.After few more tries and anger reaching dangerous levels, I decided to kill dnsmasq (Probably not needed):Code:sudo systemctl disable dnsmasqAlso I found that/etc/resolv.confwas symlinked to/var/run/NetworkManager/resolv.conf, which didn't exist.With no patience left to find out why it didn't exist, I deleted it and created a new one with these contents:Code:nameserver 8.8.8.8nameserver 8.8.4.4Apply the correct ownership:Code:sudo chown root:root /etc/resolv.confApply the new settings:Code:sudo systemctl restart systemd-resolved.serviceYay! Now it works!Of course this won't be all with OrangePi half-made products, Debian has not been updated in 3 years so apt sources are outdated.Edit/etc/apt/sources.listand replace the contents with:Code:deb http://archive.debian.org/debian/ stretch main contrib non-free#deb-src http://ftp2.cn.debian.org/debian stretch main contrib non-freedeb http://archive.debian.org/debian-security/ stretch/updates main contrib non-free#deb-src http://archive.debian.org/debian-security/ stretch/updates main contrib non-freeNow we have apt and wifi working...Finally, we can try to do something useful with this pile of sheet

author: bingo600
author_rank: Super Contributor
timestamp: July 26, 2023, 05:52:12 pm
content: I gave up on Opi-linux long ago.All my OPI's are running armbian.I haven't had any HW strangeness though, but don't have a 3G-IOTEdit:Seem like there's no Armbian for that boardhttps://forum.armbian.com/topic/8067-orange-pi-3g-iot-b-for-linux/If you haven't seen , there are some other hints herehttp://www.orangepi.org/orangepibbsen/forum.php?mod=viewthread&tid=4343&extra=page%3D1/Bingo

author: Nominal Animal
author_rank: Super Contributor
timestamp: July 26, 2023, 07:22:40 pm
content: Quote from: DavidAlfa on July 26, 2023, 05:00:54 pmMany SoCs run with 1.8V VIO, including my Odroid HC1, and the UART is directly connected to the SoC itself (as you saw how it powered the device, UART TX idling high). I can warmly recommend using proper high-speed unidirectional level shifters –– but not the bidirectional ones! they can glitch when they erroneously switch directions, causing all sorts of relatively rare but very annoying bugs –– as overvoltage could damage the SoC.I originally used SN74LVC1T45's, but recently switched toTI TXU0202for UART, TXU0204 for UART with hardware handshaking (RTS/CTS), and TXU0304 for SPI. The Schmitt trigger inputs and push-pull outputs with either end having any voltage levels from 1.1V to 5.5V makes this my choice nowadays. (Plus, at or above 3.3V, they support up to 200 Mbit/s rate.) The packages are small (0.5 and 0.65mm pitch), but if you use tweezers to bend the leads carefully, and use solid-core copper wire with heatshrink, you can dead-bug them. While I get mine from Mouser, even LCSC sells them, and JLCPCB has some in extended stock for SMT assembly, and they're not expensive.That is, when both ends share the ground potential.In cases where interfacing the SoC UART to a remote device, an another computer or separately powered MCU, I warmly recommend a level-shifting isolator like ISO6721-Q1: see mysuggested Public Domain implementation here. Either end can use VIObetween 1.71V and 5.5V, excluding the 1.89V-2.25V range, at 50 Mbits/s. A sustained ground potential difference of 240 VRMSdoesn't bother this at all. The ISO6721FBQDRQ1 costs 1.60€ at Mouser as of 2023-07-26, and only needs a couple of bypass capacitors in 0603 to 0805 footprint, so making a batch of boards to use for exactly this might be a good idea! And maybe extend the idea to ISO6742 for UART + RTS/CTS, or ISO6741 for SPI.(For I2C, it is important to use dedicated level shifters and isolators, and note if they support clock stretching or not. Not all devices need or do clock stretching, but those that do, it is very important.)

author: DavidAlfa
author_rank: Super Contributor
timestamp: July 26, 2023, 08:01:06 pm
content: Quote from: bingo600 on July 26, 2023, 05:52:12 pmYeah, those command are the same as in the manual. Wifi completely died after that.