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- Опубліковано 4 жов 2024
- Sponsored by pcbway.com/ I designed and built some serial to usb adapters based on the CH340E converter chip. The PCBs turned out beautiful with matte green soldermask and immersion gold finish, check out the video for some close-up shots.
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#VoltLog #CH340E #USBSERIAL - Наука та технологія
I appreciate that you let us see this kind of things happening.
These things happen, it's normal, they shouldn't be hidden 😁
Thanks for sharing this video, It's nice to be reminded anyone can make mistakes. You just have to fix it and move on!
thanks!
ive been digging through youtube for a video like this for so long. thank you for this!
I'm surprised you even made this video... You could have waited till the chips arrived and made a full video then... But I guess it probably has something to do with content, views and UA-cam...
I'm glad it got released. The video shows the actual process and at the end it failed because of a mistake that much likely happens to all of us every now and then. So should he have not released it just because the last part was missing? I think it's important to also show the fails that happen because they're also a big part of our hobby.
It's of course nice to build such boards, but I suppose you know that you can buy them ready to use starting at 0,50 € from Aliexpress?
Sure you can find something similar on aliexpress based on the CH340E, but what if you need a feature like switching IO voltage from 5V to 3.3V? You do it yourself.
They typically come with a yellow jumper where you can switch the I/O voltage. For the cheap CH340G modules with the transparent shrinking tube, I can confirm that switching the I/O voltage using the jumper works as intended.
Edit: On the cheap modules the 3.3 V is made from the 5 V with two diodes in series and hence it's more around 3.6 V, but that's usually not a problem. From the pictures it looks like the other design with the yellow border uses a 3.3 V regulator.
@@AS-oq7io This is about the CH340E in particular and if you search on aliexpress you will see the small breakout boards they sell do not have any jumper for selection. Also it is not clear to me if the CH340E has an internal 3.3V regulator or that's just an input pin for IO voltage and yet the breakout module from aliexpress present that pin on the edge as if it were an output.
@VoltLog The boards with the yellow border are available with CH340G and CH340E, both with voltage selection jumper. The CH340 series has no internal regulator, the V3 pin needs a different wiring depending on the operating voltage.
Multe multumiri Postei Romane!!!
I’ve been using the CP2012N and they have been very good. Faster data transfer like the Uno.
You probably meant CP2102 and yes they work fine, I've used those before as well.
VoltLog yes. That’s the one but with a ‘N’ at the end.
Careful with that chip if you ever use those adapters for anything where data loss absolutely must not happen - the GRBL project had CNC control problems at some point with parts of G-code going missing in transit (which totally can crash a CNC right into the stock), and it ended up being traced back to Arduino clones made with CH340 - the original FTDI-equipped ones never had the problem. To be fair, the Arduino is slightly off-baud due to their original choice of xtal, but the fact remains the CH340 couldn't keep up while another chip could. It's a really rare occurrence though, and of course if occasional loss is acceptable then there's no problem...
Thanks for the info! When I get the chips maybe I'll devise some kind of test to figure out if there is any loss at high baud rate.
Fast baud rates with the wrong quartz are not a good idea. A reliable design limits the baud rate error to 1 %. The CH340 supports up to 2 % based on his datasheet.
Oh, absolutely. It's just that GRBL was using 115200 for adequate throughput and apparently nobody realized the Arduino Uno that its hardware is based on happens to be absolute shit at that particular baud rate because of its specific xtal and available divisor rates. Since you mention numbers, I got curious - this may well have been a case of marginal performance: the FTDI that original Unos used to come with appears to accept 3% error and the Uno seems to be producing... 2.1% at that speed. Which might explain why this issue isn't exactly a widely known and worked-around defect.
None of this implies of course that the CH340 is inherently "faulty" or anything, under these specific circumstances, given an existing problem, it just happened to be not quite good enough. Barely. What I didn't know was that the difference that made all the difference might be so relatively small...
Yes, the allowed error is very small for a reliable RS-232 connection. Also the recommended max. receive error for the ATmega328 on the Uno is only 2 % with 7 or 8 data+parity bits. That means that even if the FTDI supports 3 % error rate, the ATmega does not. To be honest, I would not trust such a setup and my solution would be to replace the crystal of the Uno e.g. with 14,7456 MHz.
Edit: On double speed mode (which is needed to reach 2.1 % error rate at 115200 baud with a 16 MHz crystal) the max. receive error for the ATmega328 is only 1.5 % with 7 or 8 data+parity bits.
Too late now but there is a seller that has the 340E listed for $0.32 each. If your shipping prices are anything like mine (USA), the current price is $0.42 and if you select a quantity of 10 it's $0.63, for a total of $3.83 shipped. I believe that one took around 20 calendar days to arrive in the Los Angeles California area :-)
I haven't done a breakout board, I just bought one of the ones on AliEx. However, I picked up a couple of the new arduino nano compatible boards with the 340E. It works great. Linux sees it as a 341 chip. I uploaded an arduino sketch to one board. They use the "old nano bootloader" which must be selected manually.
I used the other board for trying Flash Forth 5 over the last 2 weeks. The FF5 OS uses a default baud rate of 38400 with their AVR hex file. I've used that a bunch and had zero issues. I was quite surprised, as I had a few nano's fail because of the 340G back years ago when it was just becoming common. The best I can tell those failures were due to the timing on the 340G. The fact they have an option that doesn't even need an external oscillator, and it just works is impressive.
-Jake
Yes you can find ready made boards but I did it partly for fun and partly to add some features: for example one feature I really wanted is the switch for easy selection of 3.3V and 5V. I also wanted to try out this chip to see if I could integrate it into other future projects.
@@voltlog
I did the same thing, made my own BO board, with the CH340G just to see if I could get it working consistently with a 12MHz crystal. I wanted to see how this performed next to the ceramic resonator used on the nano compatibles. I'm just too lazy to do that again. I also have to use photoresist to do MSSOP footprints instead of toner transfers. That's a lot of effort for one small board by itself. Ordering PCBs from china is looking more appealing for such things.
The ch340e has one activity pin, called TNOW. It goes high when transmitting or receiving.
Got 10 ch340e on my last LCSC order. Do not need them all, so I could send you 5. Post from Norway could be faster... Just let me know.
I have an LED connected to TNOW as well but I wasn't sure how it's going to behave so I added LEDs to RX and TX just to be sure. I can just not populate those if I don't need them. Thank you for the offer but postage would probably cost more than the chips themselves so it's not worth it. Mine are probably pretty close by now and should be getting them soon, I'm in no hurry anyway 👍
There is an English saying: "It's on a slow boat from China.."
In your case, it really is! :)
Yeah, true story!
Why did you bother to upload the video?
the usb D+,D- looks inverted, i used this chip but can be fixed with a magnetic(reversible) micro usb cable
CH340E seems really nice. I've been using CH330N lately. It comes in SOIC-8 -package, but doesn't have RTS or CTS pins.
Thanks for introducing CH340E to us, even though you don't have one yet 😆
Yup, hopefully I can also confirm the board works and what kind of baud rate it can achieve.
yes he is still waiting just like me when you order from them :)
has the chip arrived?
Looking at your schematic are the TX and RX lines still 5 volts then?
hello, is it possible to see device schematics? does your device work fine now?
I've always hand-soldered - never had the opportunity to attempt reflowing using paste, though i've seen videos about using a toaster oven for reflow. Is that what you do? Is it possible to just (carefully) use a heat gun instead?
This is what I am using, I find it more practical than an oven and it works fine for small boards.
Hot air gun, toaster, and even a stove.
ua-cam.com/video/Bb1Y9zWJciE/v-deo.html
is it possible to get schematic ?
👍I like it
I wrote down the YINGYUN Store and not to trust them. They probably drop ship or just rip you off. It not like we can do a lot about these things, I hope you opened a dispute over this.
I don't think it's the store's fault, it just takes forever for packages to be delivered to my address. The order is still under purchase protection, a dispute will be opened if the package does not arrive within the protection period but I don't think that's the problem here.
You need driver ? For this
It should install automatically, but we'll see when I test them.
Becarful of unknown device . They may need a programming . I have this problem before when you buy an empty Chip
Hehe, oeps!
Only don't get why you didn't use Vcc on the output header as well. Now you have to use the switch and change connections :(
I am crushed! After hearing some bad things about the E's, was curious if you could sustain 2 megabaud without excessive heating or error.
Your AVR chips will need a DTR connected through a small cap to to reset the target MPU for Optiboot to see it when using Arduino.
Have used several CH340G's without issue, but I resent using a huge 12mhz crystal because it will not fit into the head of a small USB male connector.
No TVS, opticoupled / clamped TX, or Mosfet driven LEDs? Hehe, there are always ways to make it more complicated.
I hope to do some testing when I get the chips to see what kind of baud rates they can sustain. It's true, there are always things you can add to make it more complicated or robust but what I did here is kinda enough for my needs.
how can you start the assembly when you dont have the components? do you put paste on and then search lab to find the components?
That's pretty much what i did and the reason for that is video recording. I need to get the recording started because it takes time, it's hot in here during summer I have to do it early in the morning and I don't have time to get everything ready from the start but rather get it done along the way.
Yep, I know the feeling. For my last project I ordered all the parts, including surface mount caps. I try to stick to 0603 minimum (prefer 0805) because my hands aren't too steady these days, unfortunately I didn't pay close attention because what arrived were these tiny microscopic dots. Turns out I ordered metric, so they're actually 0201! Way too small for me to bodge them onto the larger pads, let alone actually handle properly. So now I have to place another order. Thankfully I didn't order reels of the things, just 100 of each. If I'm going to have to order replacements, I'll just bundle them in with the next project order. It'll also allow me to rev the board for not much more, which I wanted to do anyway. Probably delay the project a month or two, which isn't really an issue for a hobbyist like me.
That almost happened to me once, I added all the parts to the cart then something didn't feel right, I don't remember exactly maybe it was the cost of the resistors or something, when I went back to double check I realized I picked metric sizes so I was able to fix it before placing the order.
Lucky catch! I gotta learn to stop putting my BoMs together at 3am!
No way ! this happened to me in another domain when I made isolation of a 40m2 room I completly forgot to pass the electrical lines behind isolation for the light buttons so I decided to go for radio controlled buttons (those that looks like real wall buttons you glue on the wall) and in fact the epic fail turned into good result :-)
Yup, things like this happen in real life 😁
Lol. That never happens to me!
LOL
Oops that will be a part 2 video :P As in Predator 2 movie sh... appens . The board looks tip top but it is very thick. Add double sided sticky tape underneath to prevent scratches.
thank you!
Not a fail yet... Shouldn't have made this video. Should have had it as a gag clip in real video. Where you realize you missed a component and shout in rage
I'm probably not that creative 😁