So I’ve always recommended the Heltec kits as a good entry-level kit but I can’t anymore due to issues with the USB->UART chips in them. What I originally chalked up as a mild annoyance has now proven to be a safety concern.

I’ve had 11 of them total. Of those, two had the USB->UART chip fail within the first week. Everything else still worked, so I was able to repurpose them as “repeaters” and manage them over LoRa. Firmware updates were a brute since I had to crack them open and use an external serial connection, but, still, I was willing to continue recommending them as entry level kits.

Cut to today and that is no longer the case after my everyday carry node decided to self destruct in a way that I am very fortunate wasn’t a fire.

I woke up and noticed the charge light was kicking on and off in a weird cadence. Clicked the button to see if it was even running (it was) but the battery was down to 30%. It was also hot. Very hot. It’s uptime was only about 5 minutes which was also odd.

So I unplug it and crack open the case. Everything on the board looks normal, so I pull the battery and hook it into USB. As I feared, it didn’t enumerate at all. Another one down, I sighed. But then things got worse. As I was holding the board in my hand (still connected over USB), I notice my finger started to get painfully hot. The hot component was the USB-UART chip.

On a hunch, I hooked my USB-C power meter inline with the cable, put it back on the USB charger it normally uses, and lo and behold, it was showing 9V. To rule out the USB charger, I tested it with another one of my Heltecs with a dead UART chip, and it was a steady 5V as expected.

So my best guess is the USB-UART failed in such a way that the data pins triggered the wall charger to go into quick charge mode and destroyed it with an over voltage. I’m genuinely surprised the battery didn’t catch on fire as hot as that chip was getting since it was right on top of the battery inside the case.

  • mesa@piefed.socialEnglish
    3·
    11 days ago

    For me all 4 have the same ussue. V3. Hope you have a better time with it than me. Im thinking of trying out some other models.

    I have two 3000mah on 2 helteks and they last around 28 hours with wifi or bluetooth. And about 10 hours more without any wifi/bluetooth.

    • Iced Raktajino@startrek.websiteOP
      2·
      11 days ago

      I’m planning to switch to the Wisblocks. The only thing I’ll lose is wifi, but I’m not using that now except on my client base node since it’s one of the ones with a failed UART chip.

      The nRF-based ones also seem to have much better battery life, and the Wisblocks can be a lot more compact if you want to add sensors or GPS, etc.

      • mesa@piefed.socialEnglish
        2·
        11 days ago

        Got a link to what your looking at? I was thinking of trying some daily carries. I kinda want one of the ones that come with a keyboard.

        • Iced Raktajino@startrek.websiteOP
          1·
          11 days ago

          Starter kit: https://store.rakwireless.com/products/wisblock-meshtastic-starter-kit

          They also have a new 1W LoRa kit I’m wanting to get to replace my client_base node. It uses the same carrier board.

          The LilyGo T-Deck is what I’ve been looking at for a dedicated node, but I can’t justify the expense right now. Plus it’d be large for an EDC.

          There’s a i2c keyboard (CardKB i think) that Meshtastic firmware supports, but I can never find them in stock. You’d just need to connect it to the i2c pins on your node.

          I’m also genuinely looking at the SenseCAP Card Tracker T1000-E prebuilt unit for my new everyday carry node. It’s super thin, waterproof, nRF-based for good battery life, and already has a GPS receiver installed. Only downside is you need to use a special cable to charge/flash it.

          Edit: I just bought the T1000-E. I had one day left on my Prime trial and decided I’d pined over it long enough. Normally I’d avoid an impulse buy like that but given what this post is about, I’m in need of a new everyday carry.

            • Iced Raktajino@startrek.websiteOP
              1·
              11 days ago

              Nice. Some reviews complain about the range/sensitivity, but it’s hard to gauge what their expectations / comparisons may be.

              My (now former) EDC is a basic Heltec V3 with its little “default” antenna in the HT Pocket case. I added a keychain lanyard and it lives with the key fob for my car. The range on it isn’t the best because of how the antenna is inside the case and up against the board (which makes it semi-directional) but it was good enough. As long as it’s as good as that, I’m content.

              • AlchemicalAgent@mander.xyzEnglish
                2·
                11 days ago

                I’m not sure what their comparison is, but the 1/8-wave antenna in the 1000E is plenty strong enough. My current ground-to-air distance record of 90+ miles is with someone in a plane who had a 1000E. It’s loads better than my Heltec V3, and out-performs everything i have except for the base stations with specialized antennas.

                • Iced Raktajino@startrek.websiteOP
                  1·
                  10 days ago

                  Excellent. I’m excited. It should be delivered tomorrow.

                  Question: Is the case able to be opened at all? Like, if I wanted to pull out the i2c and a power + ground to a second set of pogo pins? Was just thinking that the only thing I’d miss is the ability to send canned messages from the device. The 2.7 firmware lets you do that now with the one-button navigation. Thinking something like a 3D printed sleeve that has a little i2c OLED screen and maybe an extension of the user button

                  • mesa@piefed.socialEnglish
                    2·
                    10 days ago

                    The new firmware is awesome! The ability to send basic messages is what ive been wanting for a while.

                  • AlchemicalAgent@mander.xyzEnglish
                    2·
                    9 days ago

                    If you open the case it’s a one-time deal and it won’t ever be water resistant again. But even without water resistance is still an amazingly compact and well-engineered device.