Connect Chinese USB mini host to Teensy, Nano, etc

A

AaronMichael

Member
Has anyone succeeded in connecting a Chinese mini USB host to a Teensy or other board and had a program process USB input all the way to its intended output on the TX line? If so can you post a complete wiring diagram with pin functions? And the Host versions? I ask because I have read many posts on this and other forums on this subject but none claiming success and including complete methods. I would like to test a Chinese clone mini host claiming to be v2.0 (see photos included) and looking exactly like the one from DuinoFun UHS mini v2.0.

I’ve seen many partial or ambiguous wiring suggestions as well as claims of silkscreen labeling errors and other conflicting claims. I, and perhaps others would appreciate clear and accurate information to complete this project. Thanks for any and all assistance. Aaron
 

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Maybe this can help?

USB Host Shield Library, For Connecing Other USB Devices

www.pjrc.com www.pjrc.com

I haven't tested those old host shields with newer Teensy models, but I believe they should work if you follow the instructions on that page, but connect MOSI, MISO, SCK to pins 11, 12, 13. See Teensy 4.0 pinout for details.

How to power that USB host shield is complicated. It wants 3.3V power. You can power it with Teensy's 3.3V power pin, but there are 2 drawbacks because that shield is poorly designed from a power perspective.

First problem, the 3.3V power will also be sent to the USB host port to power up whatever USB device you have. USB spec says host ports should provide 5 volts and allows a range from 4.4V to 5.25V. Some devices can work with only 3.3V power, but many can not.

Second problem, hotplugging USB devices can cause a power brownout condition that reboots Teensy. The proper solution uses a current limiting chip and larger capacitor, like we have on Teensy 4.1 and Teensy 3.6. Without those, you will almost certainly have problems when hotplugging. Best to make sure the USB device is plugged in before you power up, and only unplug and plug in something else while power is off.

USB spec also requires current limiting to protect your hardware, and prevent cable melting or burning overcurrent if your power supply is strong enough to deliver many amps. This shield meets none of those requirements. Probably not a big deal for a hobby project, but something to keep in mind if your project gets wider usage.

Older version of this shield had jumper pads you could cut apart, so the MAX3412E part could be powered by 3.3V and the USB host connector could get separate 5 volt power. From your photo, looks like the design is nearly identical but with those jumper pads removed.
 
Hi Paul, Thanks for your comments and the links you have included. Have you succeeded with any of these clone hosts? I ask because there are so many complaints posted without success. The hosts I have now "look" like the original circuits@home v2.0 and have none of the obvious errors or defects reported. (See attached for example). But one never knows.

So I'm just looking for "gotchas" or other traps or time wasters.

Yes, I'm familiar with the power issue of 3.3v vs 5v and current demands of some devices. Fortunately it's easy to cut tracks on these boards. And normally feed boards with separate well filtered power supplies, 150mF & .01mF. And my designs don't normally need hotplugging. And yes, I well aware of USB specs. I'm a retired EE with microprocessor design going back to the 8048.

Thanks again and I welcome any further suggestions you might offer. Aaron
miniMistake.png
 
AaronMichael said:
Have you succeeded with any of these clone hosts?
Click to expand...

I really haven't done anything with MAX3412E since we made Teensy 3.6 and later Teensy 4.1, which have much better EHCI-based USB host.

I only ever used 2 boards with MAX3412E. One is that board you can see in the photos, which looks very similar to yours.

The other is a host shield I designed but we never brought it to market. You can see it on the leftover stuff sale page. Scroll down to "USB Host Shield That Never Was (for Teensy 2.0)".

I looked in collection of old Arduino library test hardware. This is literally everything I have left for MAX3412E. I probably did test it at some point with Teensy 3.0 or Teensy 3.2, since the left board has 14 pin sockets and the wires underneath look like they're connected to the pins needed on newer Teensy. But the reality is I mostly played with MAX3412E long ago in the days of Teensy 2.0. I really haven't done much with it since then.

1771942871357.png
 
Hi Paul,
Looks like I found the best source on the internet right here! I appreciate your advice and comments. Curiously no one else on any of the three forums I posted to confessed to completing such a project as I requested. Lots of replies on how to solder, read a schematic, learn about electronics, but no specific info relating to these shields and clones.

One further question: Do you have, or know where I might find a schematic of the circuits@home mini USB host shield v2.0? I have been unable to find one anywhere.

Thanks again, Aaron
 
This is the closest I found - not sure the site is working anymore
forum.arduino.cc

Using DuinoFun Mini USB Shield with Elegoo Atmega 2560 R3

Hi Paul, many thanks for the response. Here's some more information on the setup, and the issue at hand. The library I used (USB Host Library 2.0) is located at GitHub - felis/USB_Host_Shield_2.0: Revision 2.0 of USB Host Library for Arduino.. The sketch I used is under examples/USB host...
forum.arduino.cc forum.arduino.cc

 
I did some searching and found this. Can't be 100% certain this is really it. Nearly all the old websites have become 404 or other errors. But this PDF looks pretty likely to be the original schematic.
 

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Having just dug up this ancient info, I really want to emphasize how much better Teensy 4.1 works for USB host.

You get 480 MBit/sec speed. The controller is EHCI with bus master DMA, so it can very efficiently handle any number of USB devices (well, of course up to the USB limit of 127 per bus). Even for 12 Mbit speed is it far more efficient than USB over SPI, which almost always involves a lot of CPU overhead just to move the data between that MAX3421 chip and Teensy or whatever other processor you have.

For any new project, please do yourself a huge favor and use modern hardware like Teensy 4.1 for USB host. It really is so much better.
 
PaulStoffregen said:
For any new project, please do yourself a huge favor and use modern hardware like Teensy 4.1 for USB host. It really is so much better.
Click to expand...

Personally I have never had much luck with the knock offs that I bought. I have one of the original Circuits at home boards and they always worked. But as Paul said if you are using a Teensy 4.1 use the builtin usb host not a shield. Only time I use them now is if I am testing on a Arduino style board like the uno's etc.
 
PaulStoffregen said:
I did some searching and found this. Can't be 100% certain this is really it. Nearly all the old websites have become 404 or other errors. But this PDF looks pretty likely to be the original schematic.
Click to expand...
Wonderful! No one else has offered anything. Looking at the filename USB-miniShield-UHS_mini_10.pdf and the Rev: 1.0, I surmise it a schematic of the original ver 1.0. I wonder what changes were made for ver 2.0. I appreciate all you've done and hesitate to ask: you don't happen to have a schematic of the version you designed but never marketed? Thanks again for everything, Aaron
 
AaronMichael said:
Wonderful! No one else has offered anything. Looking at the filename USB-miniShield-UHS_mini_10.pdf and the Rev: 1.0, I surmise it a schematic of the original ver 1.0. I wonder what changes were made for ver 2.0.
Click to expand...
How hard did you look?

Example the Sparkfun USB-C Host Shield I gave a link to has a schematic part of it's documentation.

If you look at the different clones on Amazon you will find things like, this product:

Amazon.com: Mini USB Host Shield 2.0 for ADK SLR Development Tool Compatible SPI Interface : Electronics

Amazon.com: Mini USB Host Shield 2.0 for ADK SLR Development Tool Compatible SPI Interface : Electronics
www.amazon.com

Which shows a schematic for a 2.0...
1772408241618.png
 
AaronMichael said:
you don't happen to have a schematic of the version you designed but never marketed?
Click to expand...

Nope, I never made a schematic. Like most PCBs I have made, I create the PCB directly in the layout software without drawing a schematic. I only make a schematic later, if there is a need. If I had a schematic, I would have put it with the other info on the leftover stuff sale page. The 2 photos and pinouts are all the info that remains from that project 15 years ago.

EDIT: after some searching, I did find old files from 2011 which were used to build the 1 and only batch of those boards ever made. I'll attach the PCB gerber files. You can use these directly with OSH Park, or with other PCB vendors by renaming the files slightly.

Here is the parts list.

Code: 
Qty   Ref     Description             Package       Vendor     Vendor Part #

2     C1,C2   Capacitor, 10pF, C0G    SMT 402       TTI        GRM1555C1H100JZ01D
1     C3      Capacitor, 1uF, X5R     SMT 603       TTI        C0603C105K4PACTU
1     C4      Capacitor, 220uF        through hole  Digikey    P5112-ND
2     R1-R2   Resistor, 33 ohm        SMT 402       TTI        RK73H1ETTP22R0F
1     R3      Resistor, 10K ohm       SMT 402
1     U1      IC, MAX3421EEHJ         SMT TQFP44    Digikey    MAX3421EEHJ+-ND
1     U2      IC, 74LCX125 Buffer     SMT TSSOP14   Fairchild  74LCX125MTCX
1     U3      IC, TPS2045AD           SMT SOIC8     Digikey    296-3400-5-ND
1     U4      IC, MCP1700-3.3V        SMT SOT-23    Microchip  MCP1700T-3302E/TT
1     Y1      Crystal, 12 MHz         SMT           Digikey    644-1047-1-ND
1     J1      Connector, USB Host     through hole  Digikey    609-1041-ND,  FCI 73725-0110BLF
1             PCB

And here is the parts placement diagram.

hshield2_placement.png


This is truly all the info that remains from 2011. Again, no schematic was ever drawn. But if you use a program like gerbv to view the gerber files (it's higher quality rendering with transparency is helpful) I am sure you could pretty easily create a schematic. If you do, maybe you'll consider sharing it here?

Likewise, if you use these gerber files to create a PCB, even if it never gets soldered with parts, I hope you'll share photos on this thread?
 

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Last edited:
PaulStoffregen said:
Having just dug up this ancient info, I really want to emphasize how much better Teensy 4.1 works for USB host.

You get 480 MBit/sec speed. The controller is EHCI with bus master DMA, so it can very efficiently handle any number of USB devices (well, of course up to the USB limit of 127 per bus). Even for 12 Mbit speed is it far more efficient than USB over SPI, which almost always involves a lot of CPU overhead just to move the data between that MAX3421 chip and Teensy or whatever other processor you have.

For any new project, please do yourself a huge favor and use modern hardware like Teensy 4.1 for USB host. It really is so much better.
Click to expand...
Hello again,

I have no doubt about the superiority of the 4.1. When I started looking into using smaller boards instead of the full sized ones I thought it would be simple and just mean some soldering soldering instead of stacking. No intention of opening a can of worms.

However: I'm working with a limited budget, volunteering to teach music and music technology for some non-profits dedicated to promoting inter-cultural understanding for the disadvantaged for. I've been doing this for the last 25 years since I retired.

The Teensy 4.1 costs 10x what an old R3 clone costs and runs 1000x faster. Most of my projects are reading and translating MIDI at 32K coming in at the speed of fingers moving. These projects help people learn music and to understand technology.

But I definitely will try a personal project with a Teensy in the near future. Thanks again, Aaron
KurtE said:
How hard did you look?

Example the Sparkfun USB-C Host Shield I gave a link to has a schematic part of it's documentation.

If you look at the different clones on Amazon you will find things like, this product:

Amazon.com: Mini USB Host Shield 2.0 for ADK SLR Development Tool Compatible SPI Interface : Electronics

Amazon.com: Mini USB Host Shield 2.0 for ADK SLR Development Tool Compatible SPI Interface : Electronics
www.amazon.com

Which shows a schematic for a 2.0...
View attachment 38909
Click to expand...
Hi, Obviously not hard enough! I tried every way I could think of and everywhere I could think of but I ignored Amazon sales links never considering I might find it there. Thanks much! I appreciate learning new things, even at my advanced age.
 
PaulStoffregen said:
Nope, I never made a schematic. Like most PCBs I have made, I create the PCB directly in the layout software without drawing a schematic. I only make a schematic later, if there is a need. If I had a schematic, I would have put it with the other info on the leftover stuff sale page. The 2 photos and pinouts are all the info that remains from that project 15 years ago.

EDIT: after some searching, I did find old files from 2011 which were used to build the 1 and only batch of those boards ever made. I'll attach the PCB gerber files. You can use these directly with OSH Park, or with other PCB vendors by renaming the files slightly.

Here is the parts list.

Code: 
Qty   Ref     Description             Package       Vendor     Vendor Part #

2     C1,C2   Capacitor, 10pF, C0G    SMT 402       TTI        GRM1555C1H100JZ01D
1     C3      Capacitor, 1uF, X5R     SMT 603       TTI        C0603C105K4PACTU
1     C4      Capacitor, 220uF        through hole  Digikey    P5112-ND
2     R1-R2   Resistor, 33 ohm        SMT 402       TTI        RK73H1ETTP22R0F
1     R3      Resistor, 10K ohm       SMT 402
1     U1      IC, MAX3421EEHJ         SMT TQFP44    Digikey    MAX3421EEHJ+-ND
1     U2      IC, 74LCX125 Buffer     SMT TSSOP14   Fairchild  74LCX125MTCX
1     U3      IC, TPS2045AD           SMT SOIC8     Digikey    296-3400-5-ND
1     U4      IC, MCP1700-3.3V        SMT SOT-23    Microchip  MCP1700T-3302E/TT
1     Y1      Crystal, 12 MHz         SMT           Digikey    644-1047-1-ND
1     J1      Connector, USB Host     through hole  Digikey    609-1041-ND,  FCI 73725-0110BLF
1             PCB

And here is the parts placement diagram.

View attachment 38911

This is truly all the info that remains from 2011. Again, no schematic was ever drawn. But if you use a program like gerbv to view the gerber files (it's higher quality rendering with transparency is helpful) I am sure you could pretty easily create a schematic. If you do, maybe you'll consider sharing it here?

Likewise, if you use these gerber files to create a PCB, even if it never gets soldered with parts, I hope you'll share photos on this thread?
Click to expand...
Hello once again. You're really a prince of a guy! It never occurred to me to design from the layout software. But then I can use the excuse that the the boards I designed were somewhat more complex. This was back in the days of Orcad and TigerPCB? on DOS 5. And I'd plot them on a pen plotter and burn them on photo-resist boards out behind our office. Dark ages then, no SMTs.

I'll certainly keep you posted on my projects but I'm not likely to make more boards at this age. This project has already become more interesting than I bargained for. I had been happy just using full sized boards and hosts with no effort and giving them to my students.

PS. I was amused and surprised to see the 8051 listed on your website. I didn't know they had lasted this long. I was designing 8048s when the 8051 was announced and it excited our team with the new possibilities. Cheerio, Aaron
 
Found this old schematic. Again, can't be 100% sure this really is the correct one, but looks likely.

UHS_20.png
 

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And the hits keep coming! You certainly are a wonderful resource. Thank you for the latest schematic. I'll be away for the next two weeks on another adventure but will delve further into these mysteries when I get back. It has now become an interesting puzzle unrelated to any practical outcome. But I'm told to keep my mind engaged if I want to avoid becoming a fossil, at least in the short term.

And BTW, it came to me in a dream: I erred when I said Tiger PCB. It was Tango PCB we used in our shop, and that was before they added auto-router to their package. And it still exists! Now as Altium.

Thanks again for all your help, Aaron
 
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