Of course, on the far left side of the back of the PCB, between the two Schottky diodes, is the EN 10Kohm pull-up resistor. I stick with PICO-v3 because of the size limitation. As for the use of bin files to store media files, I have no technical reserves in this regard, I hope to be able to advise. I also considered the difference between 3.3V and 5V, so my simulation also tested 5V and found that there was not much change (2-3mA increase, the voltage seems to change too much). Or because of the size limit, it is impossible to achieve BUCK to 5 and LOD to 3 on such a small PCB.3V(My D class amplifier also selects 3.3V power supply). In addition, it should be noted that the design requirements of the basic Next18 interface, the actual maximum support of each interface pin is only 0.5A, so even if I use a 5V class-D amplifier, it's impossible to amplify the sound. Can you send me the schematic / parts you are using? For the MosFETs, make sure the gate threshold voltage is sufficiently low for 3v3 logic. Did you also add a DCC ACK for PROG track usage?[/QUOTE] My design is mostly based on Nagden and Kato's scheme. As for ACK, it is actually necessary to generate more than 60mA current for DCC power supply (N scale 12V). Nagden's scheme is to drive the motor directly for a short time to generate 60mA current. If there is no motor, you can also add 0.5W 75 to 100Ohm resistor. I also considered designing a high-current LED light board myself, hoping to generate 60mA of current. Nagden's latest smilesound decoder is based on the Pi 2040, also available at 12V-5V-3.3V problem (because the project belongs to the commercial scope, I can only guess) As for my schematic, I can only say that the project is still in the testing phase, there are more adjustments, inconvenient to share, I hope to get your understanding
Are there many N scale locos with Next18 interface? I haven't seen one yet myself but I haven't picked up any new DCC-Ready locos in the last couple years. Depending on the class-d amp you work with the 0.5A limit should be sufficient to drive an 8Ohm speaker adequately, the esp32 will only provide 20-30mA (depending on how many IO are "on" it may be higher / lower) but it can sink up to 40mA. I'd go for 5v (or even 12v if you can). Depending on the detector in use you might find it needs the higher voltage / current, just be sure to keep it within the limits defined in the spec. True, this will have a motor which can be pulsed to generate the >60mA ACK. Perhaps after you have the design closer to completion I can do a review of it with you just to avoid any simple mistakes etc.
Hi Atani I still have some questions to ask you, can you give me a contact information, such as email, telegram, or other instant messaging tools?
You can reach me on here via DM or discord (atanisoft #4579 NMRA Interchange, STR, OpenPnP, Monster Fight Club). I gave up on FB/IG (but kept Twitter) around four years ago, it got to be too much of a cesspool of negativity.
