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Question about serial ports on uLCD43

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  • #16
    After much hair pulling I've gotten the 8266 modules to behave. Lots of information on them coming out now. A lot of the problems people have seen with them involve improper pin to ground or vcc and not putting some waits in the loops. Too tight of a loop doesn't give the 8266 enough time to do its thing. In some of the libs now there is a wait function to take care of this. If you are going to get into these I recommend the adafruit Huzzah or Sparkfun 8266 Thing board. They have the 3.3v regulator on them the Sparkfun has a battery charger and can run on a single lipo cell but the Huzzah has the level shifter for the serial port the Thing doesn't have. Otherwise they are pretty much the same. Much easier to get hooked up and working. The Arduino IDE can be used to program them now. There is a module to load so you can use the IDE to program them directly. So far so good but I haven't really stress tested them up yet. Should be doing that later this week and I'll post up the results.



    • #17
      So how did it go?

      Did you use the AT command set, LUA or 'arduino'?


      • #18
        Not good on the stress test I went with a couple of bluesmirf's and its been running now for 3 days without a hiccup. No programming necessary with these. Just config them with a terminal and when they are turned on they bond and start the serial link. I've been running them at 115200 from an Arduino Mega. I'm going to keep messing with the 8266's seems like I find something new on them every day or so. But for now these with a class 1 radio give me 100m of range. I'm using a single cell lipo with a adafruit charger/monitor and one of their boost circuits to get the voltage up to 5v. Makes for a nice compact setup as long as you right angle the big cap on the charger. Otherwise its about 1/2 inch thicker. I used the AT commands with the 8266. Another thing I've bought 4 of them now and 2 of them were either dead on arrival or went bad shortly after. I read something the other day about them putting in some breathing room in the code so it has time to process all the background tasks and also telling the developers not to use super tight loops with them. My stuff wasn't loading it up that much but even doing these things it was still flakey. A lot of problems come from trying to use soft serial with them but even using a real serial port they put out some garbage from time to time. They come up at a strange baud rate so the boot messages look like garbage until it actually gets booted up. So when you power them up your code has to deal with all that garbage to see if it can find the ready string. Easy enough to send it commands from the touchscreen. And I think they will get the kinks worked out of them in due time. Lots of people banging on them now and it seems to be firmware related glitches. So right now I wouldn't recommend them but I think in the future they will be solid part.



        • #19
          Hmm, we are doing some research with them at the moment, so we will try to comment on some of the things we have found.

          We had a bit of trouble flashing these devices, there are lots of rules that need to be followed.
          1. They don't necessarily come out of the box with the 'same' firmware loaded
          2. Unless you are sure you have Combined bin file, make sure you flash all the files required. See 'Writing Image into Flash' in '2A-ESP8266 IOT SDK User Manual' for the segments and locations
          3. If you have NODEMCU it is easiest to use their programmer. Unfortunately, this cannot currently flash the 'user2' bin file. This appears to be only needed for 'Over the air updating', so you may not need it.
          4. To use ESP8266 'flash download tool' with NODEMCU 0.9 you must hold down the flash button and manually 'reset' the NODEMCU immediately after clicking 'start'. 0.9 has a bug that results in the 'user' button not resetting the ESP. We don't have a 1.0 board to hand so we cannot tell if this has been fixed.
          5. Flashing the ESP without a NODEMCU is a bit more complicated than just grounding GPIO1 and resetting the chip. That is just the final step. GPIO 2 + 15 also need 'setting'. CH_PD needs to be held high at all times
          6. For some diagnostics, say to see if the chip is dead, or simply the firmware is not right, set your serial monitor to 74880 baud and power up the chip.
          The ESPs al appear to be 'strict' Client + Server type devices. In our experience the 'client' end can be a simple send/receive arrangement, but the 'server' end needs some rather involved 'additions' to every send and receive. Have you seem them working as 'two clients'? (this could/should be possible, it just doesn't appear to be documented, that we have seen)