Firmware update MMDVM clone

Hier is an article, how to update the firmware of a Chinese MMDVM clone, based on the original instructies by BD7MQB.

Here is the translated simplified way to update the firmware of the MMDVM clone, to OpenWRT Chaos Chalmers with a handy web interface.

You still have to make the basic settings via the LUCI web portal, which is standard with Open WRT. Here is a link with explanation:

We assume that you can set up a ssh connection by connecting your PC via WiFi to the open network that is generated by the board. In Windows you use putty and on the Mac terminal.

Log in withrootand password 12345678

Then you execute the following instructions from the prompt: (copy these lines without [Enter] and you will not make any mistakes)

cd / tmp   [Enter]

wget      [Enter]

mtd -r write ostar-18.06-ramips-mt76x8-widora_neo-16m-squashfs-sysupgrade.bin firmware       [Enter]

After the last instruction, the board has been updated.

With a 16 Mb memory version, a restart is automatically performed, with a 32 Mb version you have to take the power off and on again. Also possible with the 16Mb version.

The ip address after the firmware update is

The AP Wi-Fi is now called ON-OPENWRT, I thought, but I changed it myself later. This AP is up and running if there is no internet connection established.

The password for the Wi-Fi AP OSTAR-AP is Open1234

Log in now with user root and no password either through your webrowser ( or SSH to the same address. By the way, it is better to set the password with the instruction passwdand then enter your new password twice.

Finally if you are stuck again:

• Press and hold the WPS 3s to turn the Wi-Fi on or off.

• Hold down the WPS 10s to do a factory reset, where everything is as it was immediately after the update.





Once upon a time somewhere in 2015 i bought a couple of these little converters RS232 tot TTL.


Here is how they work

From the RS232 Port – RX, TX and GND.  Thats the -> -<and the – signs.  Easy enough


-> RX

<- TX

On the TTL (Arduino)  side – DO NOT USE 5V use 3.3V as this toasts the device and heats up and like tops itself.  It certainly got very toasty when I put 5V across it.  This could be because I messed up somewhere in the wiring but it certainly works well for me.  I can also use the SoftwareSerial library as well so I don’t need to use TX/RX on the TTL Serial pins 0 and 1

So TTL is


-> – PIN X

<- PIN Y

For my device I used PIN 0 and PIN 1 – TX/RX – but I guess you can use other pins.

TTL RS232 Pinouts
TTL RS232 Pinouts




Hope this helps – it does work!


Openwrt/Lede & APRX

Just before years end i have compiled the latest OpenWRT LEDE & APRX, and added OpenVPN and OpenSSL to it.  The files can be found in the download section. If you have another router, then drop me a line, or call me at DMR at 204 / 2044 or 2045.

Latest Openwrt – APRX images – 19-05-2017

I have added new firmware packages and the latest APRX package in the download section. In case you need firmware for another router, please let me know and I see what I can do.

To install just the package, do as follows….
ssh into your machine (normally something like sss root@(ip-of-machine)
Then change into the tmp directory and execute:

/etc/init.d/aprx stop
chmod 755 aprx_2.9.0-Stable_brcm47xx.ipk
opkg install aprx_2.9.0-Stable_brcm47xx.ipk

In case the installer tells you that you have already the latest package, change the command into:
opkg install aprx_2.9.0-Stable_brcm47xx.ipk –force-download

Erik, pa0esh

Firmware request Openwrt & APRX

Please use this form to request a tailor made firmware for Openwrt & APRX, enabling you to setup your own iGate / Digipeater for APRS.

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