Flash Lanbon L8 without opening

[nagyrobi]

No need to open up the device and no need to solder to the board anything. You need to prepare some thin wires as standard dupont pins don't fit in the connector. For example this is made by soldering some waste 0.5W resistor feet to dupont wires:

First insert a free wire in IO0 pin (leftmost in the lower row):

Then insert RX, TX, 5V and GND in the upper row, see the markings on the pcb. You can also use 3.3V flash, but I think 5V is better if your USB-TTL adapter offers this because the display also turns on so after flashing you can see immediately if it was successful or not, and you can connect to serial port with a terminal client to see debug messages if you want to. Watch out not to short-circuit any of them:

While you plug in your USB-TTL adapter keep the free cable coming from IO0 to GND, you can release afterwards.

Erase Flash as usual (commands below for Ubuntu):
./esptool.py --port /dev/ttyUSB3 erase_flash

Disconnect the USB-TTL, reconnect again with IO0 to GND like before and write Flash:
./esptool.py --port /dev/ttyUSB3 --baud 460800 write_flash 0x0 lanbon_l8_full_8MB_<version>.bin

Disconnect the USB-TTL, reconnect, and see what's happening. Watch the bootup procedure with screen /dev/ttyUSB3 115200.

Good luck!

[fvanroie]

Can we add these pictures and information to https://fvanroie.github.io/hasp-docs/#devices/lanbon-l8 ?

[nagyrobi]

Of course!

[fvanroie]

Question: Would it be possible to make some 800x480-ish photo's like the last one?
Resizing and cropping these to fit wouldn't scale as nicely.

[nagyrobi]

I think simply scaling them to the same width is enough, height is content-dependent... I specifically cropped down parts from top/bottom of these because they were just non-informative white plastic surfaces.

[erwin]

Tips from the perspective of a software guy with very limited hardware experience trying to get this working.

You'll need to "connect".

RX, TX, 5V, GND (ground) and GPIO0

Important: Wire Size

Getting wires that are the correct size for the lanbon's ports can be a bit tricky. I bought a few different wire sizes they were incorrect. Finally on my 3rd or 4th order I managed to get pins that were the right size.

| USB TTL | → | Lanbon L8 |   |
|:-------:|---|:---------:|---|
|   GND   | → |    GND    | ╮ |
|    5V   | → |     5V    | │ |
|    TX   | → |     RX    | │ |
|    RX   | → |     TX    | │ |
|         |   |    IO0    | ╯ |

To get a cable to connect the Lanbon's IO0 to the Lanbon's GND I sliced open a Cat-6 ethernet cable and used the individual stands from inside that.

If you're wires are too big you'll damage the connectors (which are also required for daily operation!) and if your wires are too small, they'll just fall out and you'll have an immensely difficult time flashing.

Note that when flashing, these voltages are very low. When my fingertips were touching the GND pin as I was holding IO0 onto the GND pin, it never shocked me.

Example "Wiring Harness" photos:

Connecting and Flashing Step-by-Step

1. It's a little easier to connect the wires with the back cover out of the way. If you have trouble getting the pins in, just remove the 4 screws and remove the back cover. Be gentle though, there is a wiring connecting the two sides of the plate that you don't want to tear out.
2. Disconnect USB TTL from your Computer's USB Port
3. Connect a loose wire to IO0, this is on the bottom row of pins so we'll connect it first, and we must manually connect it to GROUND while we power cycle... Just leave the other end hanging for now.
4. Connect GND on USB TTL to GND on Lanbon
5. Connect 5V on USB TTL to 5V on Lanbon
6. Connect TXD on USB TTL to RX on Lanbon
7. Connect RXD on USB TTL to TX on Lanbon
8. Double check that the IO0 wire still has one end inside of the IO0 port.
9. Loosen the GND wire a little (pull it out about 2mm) and connect the other end of the IO0 wire to the GND wire. DO NOT LET GO... Hold these.
10. Now, boot the Lanbon into Flashing Mode by connecting the USB TTL into Computer's USB Port
11. Once the Lanbon boots to a solid WHITE SCREEN, that's the indicator that it's in flashing mode. If it boots anything else, such as the default software, double check each step, especially:
    • Step 9 Lanbon IO0 connected to Lanbon GND
    • Step 6 USB TTL TXD connected to Lanbon TX
    • Step 7 USB TTL RXD conneted to Lanbon TX.
12. Stop holding the IO0 wire to the GND wire.
13. While everything else is still connected, run sudo esptool.py or whatever the flashing tool on your platform is. For me the command was:

sudo esptool.py --port /dev/ttyUSB0 --baud 460800 write_flash 0x0 ~/Downloads/lanbon_l8_full_8MB_v0.6.2.bin

esptool output when successful looks something like:

esptool.py v3.2
Serial port /dev/ttyUSB0
Connecting......
Detecting chip type... Unsupported detection protocol, switching and trying again...
Connecting...
Detecting chip type... ESP32
Chip is ESP32-D0WD (revision 1)
Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse, Coding Scheme None
Crystal is 40MHz
MAC: 34:86:5d:42:b6:9c
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 460800
Changed.
Configuring flash size...
Flash will be erased from 0x00000000 to 0x001abfff...
Compressed 1749632 bytes to 993268...
Wrote 1749632 bytes (993268 compressed) at 0x00000000 in 24.0 seconds (effective 582.3 kbit/s)...
Hash of data verified.

Leaving...
Hard resetting via RTS pin...

The important thing is that you'll see data being successfully transferred.

1. If you're not getting the white screen, double check each wire connection
2. If esptool isn't flashing the Lanbon, remove and replug the USB-TTL (make sure the Lanbon still comes up with the White Screen (flashing mode).
3. If you flashed it, but it still doesn't boot, make sure you're using the correct firmware: lanbon_l8_full-something...

I flashed 5 more of these today using the process above and it worked great for me.

[janick]

Has anyone flashed a L8 with the new 0.7.0 firmware yet?

And if so, which of the three binaries did you use?

[janick]

Thank you. And did you use one of the pre-built binaries (in which case which one?) or did you build your own (in which case would you mind adding it to the repo)?

[erwin]

I build my own but I include the a two Chinese fonts in the bundle that others may not want.
When I next rebuild though, I could try to do a stock rebuild as well and share that image.

Here's the current image that I'm running, but when I re-build I will post new ones...
I can't remember if it's the full or the ota version that works with the lanbon when doing the update via the Lanbon's OpenHASP WebUI.

lanbon_l8_.zip

[fvanroie]

Automated builds can be downloaded from Github Actions or either https://nightly.openhasp.com

[janick]

Automated builds can be downloaded from Github Actions or either https://nightly.openhasp.com

Awesome! Is there a link to that nightly build page somewhere on the http://openhasp.com site? I looked everywhere and I know I didn't find it.

[fvanroie]

e.g. Flash ESP32
If you have suggestions for improving the documentation, you can click the pen icon at the top of the page.