Community Forum
    • Blog
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Groups
    • Register
    • Login

    ESP8266 Reset and CH_PD pins for FTDI auto reset

    Scheduled Pinned Locked Moved Blog articles comments
    ftdiresetesp8266chpdauto
    12 Posts 7 Posters 5.1k Views
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • CharlesC Offline
      Charles
      last edited by

      Today I solved one of my “Auto-reset” like problem for ESP8266 which had some erratic comportment depending on ESP module used. Sometimes it was working all time and some other never. Investigation was planned, I really don’t had time for this but I like to understand what happens, and why ! I also wanted to share this with you and able to discuss on it.… Continue Reading

      Click here to see the full blog post

      1 Reply Last reply Reply Quote
      • P Offline
        phermansson
        last edited by

        Interesting! Do you need the schottkys if you use a 3.3V supply?

        1 Reply Last reply Reply Quote
        • CharlesC Offline
          Charles
          last edited by

          @phermansson
          no you won't, you can remove D1 and D2 but need to leave D5

          1 Reply Last reply Reply Quote
          • C Offline
            cranphin
            last edited by

            Hi! this is cool 🙂
            Some questions:
            I'm using a similar design with a CP2102 which only has DTR, and operates at 3.3V.

            • You say that in this case D1 and D2 can be removed, I assume these are the same in the first and second diagram? (they are not numbered in the second diagram 🙂 ).
            • Is the reason to use Schottky (only) the low forward voltage? I only have some 1N4148, using one for D5 seems to work, using it for D1 and D5 does not for some reason 🙂
            • The B5819W would be the same as 1N5819 I assume? Might order some, do you think it's a good common Schottky to have? 🙂
            • How do you make this work in software??? Setting DTR on, then off, does put it in flash mode, and Arduino software in NodeMCU mode does manage to flash correctly. But Arduino Serial monitor seems to set the DTR wrong, then it stays stuck in flash mode 🙂
            1 Reply Last reply Reply Quote
            • CharlesC Offline
              Charles
              last edited by

              Yes they are the same diodes on the 2nd diagram. I think it should works with 1N4148, tell me if it's the case, I'd like to know. And yes Schottky to avoid approx 0.6v dropout voltage, just that.

              On software, view, I just set in Arduino IDE NodeMCU board and all id then fine (ck reset type as far as I remember), that's all 😉

              1 Reply Last reply Reply Quote
              • C Offline
                cranphin
                last edited by

                Well, I've something that works good enough for me now 🙂

                • With a CP2102 (3.3v) just 1 1N4148 for D5 seems to work (removing D1 and D2). For safety I put a 470 ohm in series with D5. This is using the CH_PD diagram.
                • Uploading works like this with stock Arduino (Actually I have it set on NodeMcu mode).
                • But serial monitor messes it up, so instead I use non stock Arduino IDE from: https://github.com/esp8266/Arduino/issues/316 it disables serial monitor messing with DTR/RTS :).
                1 Reply Last reply Reply Quote
                • F Offline
                  Flapjax
                  last edited by

                  Can not get this to work on a ESP12F at 3.3V. I am using the 'ch340' USB>TTL and there is a DTR and RTS on it. AI Thinker default firmware works so its talking to the adapter. I have removed the D1 and D2. I only have '4148' diodes. I'm suspecting the 100nF capacitor might not be enough. I don't own an oscilloscope, maybe my logic analyzer could tell me something.
                  12K pull-ups.

                  Here is my project http://imgur.com/a/PKArc

                  1 Reply Last reply Reply Quote
                  • F Offline
                    Flapjax
                    last edited by

                    Aha. The issue from my previous comment was because the ch340 documentation had different package than what i have on my adapter. 20 pins Vs. 16 pins.

                    1 Reply Last reply Reply Quote
                    • M Offline
                      Marian
                      last edited by

                      I tried it today and it works. Only used the diode that connects to gpio0 and the capacitor. I didn't used the other 2 diodes. The diode I used is a regular 1N4002. It doesn't work everytime, because sometimes it gives me the "espcomm_upload_mem failed" but it gave me that error before when I used the buttons method and I could see clearly that the ESP8266 is in flash mode in serial command window. So this circuit is not the problem of that error.
                      Thank you Charles!

                      1 Reply Last reply Reply Quote
                      • Z Offline
                        ziplockk
                        last edited by

                        Hi,

                        I'm using a 3v3 only variant of this circuit but that should not be a factor.

                        Noticed a lot of issues with (some) modules (on some board designs) not entering or randomly not entering programming mode to various degrees. After some prodding I ended up increasing the size of the 100nF cap to 10uf and all problems disappeared over all the modules I'm using. Seems that startup timing can change between modules. My reference schematic here : https://www.dropbox.com/s/2b2c7zq3yp67ouu/Screenshot from 2019-01-13 16-52-00.png?dl=0
                        HTH
                        Fd

                        1 Reply Last reply Reply Quote
                        • Z Offline
                          ziplockk
                          last edited by

                          Oh, also forgot to mention, have also observed problems with schottky's with larger reverse leakage currents, the BAT48Zfilm works where these other diodes don't, haven't had time to nail down precisely why yet as the alternates had a lower voltage drop, only other difference was larger reverse leakage current.

                          1 Reply Last reply Reply Quote
                          • P Offline
                            Psi
                            last edited by

                            Sadly I could not get it working. Tried different Elkos and Kerkos and used a SS16.

                            1 Reply Last reply Reply Quote
                            • First post
                              Last post

                            6

                            Online

                            5.7k

                            Users

                            534

                            Topics

                            5.0k

                            Posts

                            Top Topics

                            • Bonjour Nicolas
                              G
                              Gilles15001
                              0
                              15
                              229

                            • Denky 4 - Domoticz - Triphasé -
                              Nicolas BernaertsN
                              Nicolas Bernaerts
                              0
                              7
                              36

                            • Denky D4 et Linky Standard TInfo Rx Non Configuré
                              CharlesC
                              Charles
                              0
                              5
                              92

                            • CC1101 mini shield pour raspberry
                              CharlesC
                              Charles
                              0
                              5
                              133

                            • CC1101
                              CharlesC
                              Charles
                              0
                              2
                              46

                            Popular Tags

                            teleinfo
                            24 topics
                            arduino
                            19 topics
                            remora
                            16 topics
                            esp8266
                            10 topics
                            arduipi
                            10 topics
                            wifinfo
                            7 topics
                            raspberry
                            7 topics
                            broadcast
                            7 topics
                            Copyright © 2022 Charles-Henri Hallard | Return to blog page | Powered by NodeBB