Improved performance 5V Arduino Nano/Mega compatible

[DC1MC]

Did you look into the SWD programming?

For what I found Nuvoton offers some tools on github (https://github.com/OpenNuvoton/Nuvoton_Tools) and mention openOCD, but the firmware for the interfaces seems to be closed source, and the NU-LINK2-PRO they point to is bloody expensive. Have not checked if there are cheaper options available.

Pre loaded boards make it usable with Arduino framework and maybe usable for partial bare metal, but for those who do like full bare metal it would be nice if reusing ST-Link devices was possible.

Good question, here's my solution:

The development kit for the MCU, mentioned in the first post, costs 26USD  + 20USD Shipping:
https://direct.nuvoton.com/en/numaker-m471r1

The devkit is panelized, like the ST Nucleo boards and it has a ST-Link Nu-Link  programmer that can be detatched to be used for programming of the empty or software damaged boards.
The "professional" NULink has strange features (like limiting the number of programing times on a specific device !!!) and I couldn't care less about it.
I'll attempt of course to get a programming protocol documentation, or just observe it with LA to see how far away form the ST link is, I think as well that it may not be that far.
For people that want to be involved in the software development and live in Germany or around, I can order a few extra devkits to spare the costs, or you can get them on your next Digikey order where is seem to be available.
Even in EU but outside of DE, we should be able to find a cheaper shipping option.

Cheers,
DC1MC

[pcprogrammer]

I found this one on aliexpress. Not as cheap as an ST-link clone but way better than the USD 149 for the pro 

https://nl.aliexpress.com/item/32815222785.html

Edit: Also found the same as you mention but it is more expensive. https://nl.aliexpress.com/item/1005004788738430.html
I do wonder if buying from nuvotondirect is charging TVA for selling in Europe. Could not find any info about it with a quick scan. If not you have to add the TVA and the duties the postman charges.

[spostma]

a tiny suggestion; also allow SMD mounting of the board by having one-and-a-half drilled hole
(castellated 'post stamp' + through hole pads) like ESPxxx modules often have (detail attached)

[pcprogrammer]

On the subject of programming, it looks like it does work with the ST-Link device, at least according to this post: https://www.eevblog.com/forum/microcontrollers/any-experience-with-nuvoton-mcus/msg4315357/#msg4315357

[DC1MC]

On the subject of programming, it looks like it does work with the ST-Link device, at least according to this post: https://www.eevblog.com/forum/microcontrollers/any-experience-with-nuvoton-mcus/msg4315357/#msg4315357

As expected then  , the SWD host is also interesting on those bakemons of a MCU, too bad they're 3V3, but maybe sometime we'll get some board with them as well, they're just a bit more expensive.
In the meantime let's focus on our guys here
 Cheers,
 DC1MC

[DC1MC]

a tiny suggestion; also allow SMD mounting of the board by having one-and-a-half drilled hole
(castellated 'post stamp' + through hole pads) like ESPxxx modules often have (detail attached)

Well, I was of the impression that most people doesn't lake castellation, and mind changes, I guess we could do it if JLCPCB offers it, in the end we are still taking about Arduino clones, hot high-end boards ?

 Cheers,
 DC1MC

[tooki]

@tooki - no micro-USB will be in a design of mine  , the Nano like board with LEE will have micro-USB like the original Nano, the "advanced" board, with SEE and 40 pins, will have USB C connector. The 3V3 variants that nobody cares, is not that they aren't significant or super widely used, nobody cares to make a new one because most of the sweet spots for that platform have been already reached.

I assume you meant to say “no mini-USB will be in a design of mine”?

a tiny suggestion; also allow SMD mounting of the board by having one-and-a-half drilled hole
(castellated 'post stamp' + through hole pads) like ESPxxx modules often have (detail attached)

Well, I was of the impression that most people doesn't lake castellation…

That’s a strange conclusion to arrive at, since two people spoke out in favor it it, and just one person spoke out against it (not because they don’t like the idea, but because it’s harder to manufacture).

and mind changes, I guess we could do it if JLCPCB offers it, in the end we are still taking about Arduino clones, hot high-end boards ?

”High-end boards” like $3 ESP32 modules?!?
It’s certainly not something limited to expensive boards.

[DC1MC]

@tooki - We'll give it a try, we couldn't dream to reach the volumes of the "$3 ESP32 modules", and JLPCB says that they have two castellation processes, the standard one, where they say errors may appear and a bit more expensive one that is quality guaranteed. We'll cross this bridge when we'll reach it, in the meantime and in the light of the latest developments (please see the edited first post), are there any suggestions for the pin assignments  for both modules ?

I really want to put this show on the road, so I'll start doing it myself if none jumps, but I want to avoid duplication of the effort, but if there are no volunteers until the evening I'll start working on it.

 Cheers,
 DC1MC

[pcprogrammer]

For the plus version it does not matter I think. Keep the port order along the pins or maybe create a proper bus arrangement based on the EBI.

It is the EBI bit that I find interesting as a way to allow reusing a lot of old 5V hardware I have lying around.

The Arduino nano compatible version does not lure me at all.

[DC1MC]

For the plus version it does not matter I think. Keep the port order along the pins or maybe create a proper bus arrangement based on the EBI.

It is the EBI bit that I find interesting as a way to allow reusing a lot of old 5V hardware I have lying around.

The Arduino nano compatible version does not lure me at all.

Perfect, somebody gets it  , so Nanoton+ will be born first

 Cheers,
 DC1MC
 

[DC1MC]

Hello, after looking a bit closer on the chip I have a couple of news for Nanoton+ and some questions and news:

- First the bad news: 40pins are not covering enough of the features, is either 2x26 52 (ca. 66x25.4mm) for full coverage, or 2x32 64 (82x25.4mm) for eventual future expansion, please let me know your opinion about what you think is best and what you you'll prefer. Not very Nano anymore  , but at least there will be enough place for LEDs and buttons (the sizes given are the max outline sizes).

- A good news: There is an independent digital domain power pin V_ddio and 6 I/O in this domain PE.13 to PE.8, the V_ddio can go in between 1V8 and 5V. As for the functionality one can configure there either a SPI port, a UART (with control signals) or an I2C, and so we can finally satisfy the people saying that "well, I like 5V but I have this 3V3 or 1V8 module...". Youpiee   

- A question: there is a band-gap analog reference of 1.21V for the ADC, should we leave it decoupled but un-exported, or should we export it, for people to do unspeakable things to it  ?

-Last call for the forum members living in DE (5.99) or EU(13.99) that want to have a development kit and/or some parts, I will place the order tomorrow evening and find out the VAT situation  , you can piggyback on my order if you like or I can piggyback on yours if you also plan.

Cheers,
DC1MC

[pcprogrammer]

I opt for 2x26 pins to have full benefit of the MCU.

The fact that 6 pins can work on a different voltage is very nice. What setup do you have in mind to control this voltage?

About the ADC ref voltage I don't mind if it is only decoupled on the board and not available on the pins.

I will wait for the finished board and it's pricing before jumping on the bandwagon.

[djsb]

I'm just keeping an eye on developments at the moment. Will this project be open source, and will it use KiCad for the PCB design? Will the source code also be open source? Are we free to download the design files for local adaptation?

[DC1MC]

I opt for 2x26 pins to have full benefit of the MCU.

The fact that 6 pins can work on a different voltage is very nice. What setup do you have in mind to control this voltage?

About the ADC ref voltage I don't mind if it is only decoupled on the board and not available on the pins.

I will wait for the finished board and it's pricing before jumping on the bandwagon.

The V_ddio can be either controlled from outside or tied to the 3V3 on-board LDO that I will put for the people that want to use the whole system at 3V3, I think (pins permitting) I will export it as well and put a big fat 0ohm R or a jumper, because the moment we'll make it permanent to 3V3, there will be voices asking for 2V5, 1V8 or even 5V, so rotating R will be (5V, 3V3, outside voltage).

Also what about V_ref ?

 Cheers,
 DC1MC

[DC1MC]

I'm just keeping an eye on developments at the moment. Will this project be open source, and will it use KiCad for the PCB design? Will the source code also be open source? Are we free to download the design files for local adaptation?

Q1) Will this project be open source ?
A1) Yes, open source as stated in the beginning.

Q2) And will it use KiCad for the PCB design?
A2) Maybe, if someone offers to help to do the design in Kicad, the friend that offered help is an Altium professional and is the only way to get the proper full manufacturing package for JLCPCB including BOM and technology stuff (castellation and so on), nobody offered here, I'll see about maybe someone will jump after the schematic solidifies. If someone offers to either import, or redo the project in Kicad is most welcome.

Q3) Will the source code also be open source?
A3) Yes, with GitHub page.

Q4)  Are we free to download the design files for local adaptation?
A4) Yes, I'll be glad to have "baby projects" out of it, but please pay attention the OSHW license !!!

Unasked Q1) How would you expect to make money out of it ?
Unasked A1) Well, I really don't, is mostly and itch to scratch for me, but I'll do offer SW support, accept proprietary changes and maybe offer the boards in a commercial setup if they pick up speed, I do wish German government will be less bloody hostile to microcompanies, not anybody could be Zalando .

Cheers,
DC1MC

[djsb]

I might have a go at importing the Altium files into Kicad 7.xx, and then they can be shared. What version of Altium Designer is going to be used? Thanks.

[pcprogrammer]

For a review by me or others on the forum, a pdf export of the schematic and pcb layers is probably the easiest.

As a hobbyist I use EasyEDA to draw schematics and pcb's. Have used JLCPCB for making the pcb's, and that was easy since they are affiliated, but have no experience with their full assembly options, so no help there.

[DC1MC]

For a review by me or others on the forum, a pdf export of the schematic and pcb layers is probably the easiest.

As a hobbyist I use EasyEDA to draw schematics and pcb's. Have used JLCPCB for making the pcb's, and that was easy since they are affiliated, but have no experience with their full assembly options, so no help there.

Preliminary PDF files will definitely be published here for constructive criticism and improvements, until we reach a feature stable version agreed of most of the interested, then the PCB v1.0 will be produced.

The MCU version with 0.8mm pitch is really in a BIG package, 14x14mm, and even with latest widened format it may prove difficult to route, it does have the advantage of still being able to be hand soldered without pasta, stencil and oven, the 0.4mm 7x7 intended to use originally is better left to machines . But in the rather unlikely eventuality that we'll be able to place the big guy, then I/you should be able to solder everything by hand if needed without the need to use assembly services.

Cheers,
DC1MC

P.S @pcprogrammer: Would you like to use EasyEDA to design this stuff as well  ? Mostly asking for PCB.

[pcprogrammer]

P.S @pcprogrammer: Would you like to use EasyEDA to design this stuff as well  ? Mostly asking for PCB.

Sure, I can give it a try.

[DC1MC]

This is my EBI-centric attempt to assign the pins in the 52-pin frame, if someone has any better, argumented proposal, kindly please edit and post, also if I forgot something obvious.

nRESET           1          27 VIN   
EBI_NCS0   PD.8  2          28 GND   
EBI_ALE    PD.9  3   SWD    29 3V3   
EBI_nRD    PD.1  4          30 GND   
EBI_nWR    PD.2  5          31 VBAT   
EBI_MCLK   PD.3  6          32 GND   
EBI_ADR16  PD.12 7          33 PD.0   
EBI_ADR17  PD.13 8          34 PB.15  EBI_NCS1
EBI_ADR18  PD.14 9          35 PB.4   EBI_AD7
EBI_ADR19  PD.15 10         36 PB.5   EBI_AD6
EBI_AD8    PC.0  11         37 PB.6   EBI_AD5
EBI_AD9    PC.1  12         38 PB.7   EBI_AD4
EBI_AD10   PC.2  13         39 PA.3   EBI_AD3
EBI_AD11   PC.3  14         40 PA.2   EBI_AD2
EBI_AD12   PC.4  15         41 PA.1   EBI_AD1
EBI_AD13   PC.5  16         42 PA.0   EBI_AD0
EBI_AD14   PC.6  17         43 PB.0   EBI_nWRL
EBI_AD15   PC.7  18         44 PB.1   EBI_nWRH
           PE.8  19         45 PB.2   
           PE.9  20         46 PB.3   EBI_ALE*
           PE.10 21         47 PD.7   EBI_nRD*
           PE.11 22         48 PF2   
           PE.12 23         49 3V3   
           PE.13 24         50 PF.6   ICE_DAT
           VDDIO 25         51 PF.5   ICE_CLK
             GND 26   USB   52 GND 

[DC1MC]

No feedback on the pin assignment, should I proceed ?
NEWS: Some MCUs and dev kit, ordered order is processing.

 Cheers,
 DC1MC

[pcprogrammer]

You seem to be in a rush 

Did not see your post about it untill this morning, due to my early bedtime, and had no time to respond due to other business.

One thing about it is a missing 5V output/input pin, and what are the specs for the vin pin. For the rest it looks good.

I know the idea is to have selectable supply voltage for the MCU, but I think it is best toward the outside world to have the voltages at fixed given levels on the pins.

[DC1MC]

All pins will have fixed voltages, except Vin (2.5 -5.5V) main MCU power, and Vddio that will be selectable, by default tied to the MCU main power supply, the enterprising people will move Vddio to other provided powers moving the onboard R to one of the three positions.

I think we can live with this, what say you gentlemen ?

 Cheers,
 DC1MC

[pcprogrammer]

So vin is the MCU supply and not like on the Arduino nano the allowed range 7V-12V to be regulated to 5V.

I thought the idea was to have it run on either 5V or 3V3 with a jumper or 0 ohm resistor selector option.

How do you see it in relation to the USB 5V supply?

[DC1MC]

Sorry, fully confused, discard the previous answer, the Vin is indeed the unregulated unregulated supply as Arduino, the output is 5V and 3V3, the MCU could run at at 5 or 3.3V, the 3V3 will be exported for Vddio and external modules, onboard one could select the MCU in between 5/3.3V, the Vddio separately between 5/3V3/external and I will consider the USB as 5V, have to make a descriptor to request 1A and that's it. Maybe on a later variant I will put a real USB-C power management to request different voltage to feed some SMPS do get more power for the external modules, but for now I will stay with LDOs, to see how the SW and the whole MCU performs.


 Cheers,
 DC1MC