BluepillF4 PCBs

**UPDATED**

Seems like Squonk has the final design in the F4 board, and perhaps we can order the PCBs soon.
As mentioned in the AllPCBs thread, thanks to all the people that signed up with the link, I can order PCBs with the bonus.
Just found out while ordering that the bonus can’t be used to pay for an order, but just to obtain a 10% discount, so the boards were not free.
Anyway I am ordering a bunch of 40 for the US, way more than I would assemble ever, so the offer stands to ship some to people willing to assemble some.

I live in the US, and have a diy reflow oven that has worked fine for me so far. I am not set for volume production though.
I can ship a bunch of bare PCBs to anyone in the US for the cost of shipping, that should be under $1 (I believe we don’t need bubble envelopes for bare PCBs).

I can reflow a few with the passive components, and you are left to solder voltage regulators and MCU, since they are larger they are normally easy to solder with an iron if you have a bit of experience, but that will depend how many people ask for it, since like I said I’m doing it manually so it takes a good amount of time.

These are still prototype PCBs, so we may find flaws, you may find traces that you need to cut and run a piece of wire, you may even have to trash a board altogether if there is a short that kills your MCU, so ask for PCBs if you understand this is not to get a final commercial product, but rather to contribute with your time to check and test them, and each board will cost you a few $ in components and a few hours of your time. There are a lot of small 0603 components.

If you want to assemble a few and test them, please post here how many PCBs you think you will want.
If you can’t deal with the 0603 components but think you can take care of the MCU, regulators, usb port if I reflow the 0603 components, say so, and I’ll see how many I can reflow.

Bare boards will go first, and only I have enough time and after I assemble some for myself, may be able to reflow a few for other people.

I would just buy the minimum order of PCBs

IMHO with such a compact board,there is a high lightlyhood of there being a small but critical error, or perhaps a tolerance which is too tight for the cheap manufacturing plant

I worked in the electronics industry quite a few years ago, and virtually every board that was designed had at least one problem.
Sometimes this was minor and we could compensate in the firmware etc, but often we had to slightly modify the PCB at least once.

I know in this case , we have many very talented people looking at the PCB, but as it’s Sooooo compact and uses a processor we don’t use that often, I still think there is a chance the boards won’t fully function correctly.

Of course, I agree with you Roger, same experience!

The thing is, 5 boards cost $13. 55 boards cost $20.
If it works or it doesn’t cost about the same. If I order 55 at once, and it does work, then there is 50 more to send around.

[victor_pv – Sat Feb 03, 2018 10:32 pm] –
The thing is, 5 boards cost $13. 55 boards cost $20.
If it works or it doesn’t cost about the same. If I order 55 at once, and it does work, then there is 50 more to send around.

I know there was a good deal of interest originally and I was even interested in assembling one. But that like 90 days ago. Today, I am distracted with other interests and if I were to procure a board, it would likely never get assembled. Time changes everything.

I think the design effort for the board is fantastic and I think a completely assembled board would be highly desirable if in the $5 range, but with the ESP32 pricing now under $5 and the rPi_Zero-W at $5 (sale) here in Atlanta, I just do not see myself taking the time to 1) source and order the uC and 2) assemble the board.

I have really enjoyed reading the ongoing discussion and decisions made in the long main thread; enlightening stuff.

Ray

You can add the Onion Omega 2 to the list of cheap boards.

But regarding all other competitive boards, the situation has not changed much in 90 days: maybe the ESP32 is now a little bit cheaper, but it was already in the <$7 game then. I know this one and the smaller ESP8266 very well (I helped to support the Xtensa CPU in GCC), but the cons are the number of GPIOs and high power consumption. Great board though, I am also using it a lot!

As for the RPi0W, the situation is not that simple: if you can get some at MicroCenter for $5 (lucky you!), for most of us here in Europe, it is difficult to get one below $20 with shipping

I agree the STM32F4 only fills the needs for a niche market between these boards and the cheaper Arduino mini/micro and BluePill boards in the <$2 range.

But with a 168 MHz / 210 DMIPS Cortex M4 with single precision FPU, DSP instructions and its plethora of peripherals, the STM32F4 addresses applications requiring high-processing power and real-time control, such as flight controllers in drone applications, where they dominate all other MCU types by far.

Of course, assembling a board from scratch takes time, but it is fun and rewarding, and it is up to everybody to see an interest in it!

Assembling such a board is fun for us who work with 0603/bga/qfn and are equipped with tools and with skills
99% of people who want to pay and play are unhappy when ie. even the pin-header is not soldered in already..
This board to assemble at home would require some experience, however.
Thus for US market you have to offer a fully assembled board for $5, as the Arduino Company and Raspberry Pi Foundation do

Yes, most users will want assembled boards. This version is still a prototype to be tested even for its most basic functions (e.g. turn on power), so this is different. We will be able to deliver some PCBs to volunteers, but expect tears, sweat and blood. No guarantee whatsoever that it will work for application X, Y or Z.

Then once we have a working prototype, we can make plans to have them manufactured and shipped pre-assembled (W/ or W/O pin headers soldered) directly from China, as this is the only effective distribution channel: for Rpi0W, the main online distributors are charging a lot for shipping, and small online shops tend to bundle this with junk to get a minimum amount order of at least $10, then you get additional $5 shipping fees.

But the first step is debugging the initial prototype board!

Oh, my, my regrets for causing this thread to go off topic … I seem to be a lightning rod for such things.

But with a 168 MHz / 210 DMIPS Cortex M4 with single precision FPU, DSP instructions and its plethora of peripherals, the STM32F4 addresses applications requiring high-processing power and real-time control, such as flight controllers in drone applications, where they dominate all other MCU types by far.

Those that follow my rants know that I am a big proponent of using high performance, low cost microcontroller boards in conjunction with RTOS higher level products for providing near-real-time data aggregation.

My intent on posting was to clarify why I wanted a board to assemble back at the start of Autumn ’17 and now mid-way into 1Q18, I am no longer interested. My decision certainly should not reflect in any manner on the usefulness of the design. Many members seemed interested in having an initial board and in doing the evaluation, I am just removing my name from that desire so someone else can participate.

Ray

Ray, and I think you make a good point, things move fast.
I decided to open this post because another forum member sent me a PM saying he would be happy to get some PCB and try to assemble to join in the effort of developing the prototype.
As long as people understand this is a prototype and the effort required, I think there is value letting more people test it, so we may move along faster, so I decided to open the thread to let people willing to join the effort know I can ship some bare PCBs to them, and if I have the time, I may be able to solder the SMD components in a few boards. While I can only work in a board at a time, if 5 other people is testing them at the same time I am sure we will move faster in finding any correction needed, or if there is no flaws in testing GPIO, peripherals, clocks, RTC, etc etc.
We are not yet at the stage of mass producing them, but perhaps we can get to that point soon.

No problem Ray!

No, this is not off topic, it is always useful to see the whole picture when you are focused on a subject.

There are a lot of low-cost boards available now for tinkering with, and this is a good thing. Among the inexperienced users, the low-cost Arduino micro/mini clones are the most used. For more power users seeking the lowest possible cost, the BluePill boards are a must.

OTOH, there are software-only people who are looking down to hardware stuff, and their favorite platform is then the RPi, because it is relatively cheap and you can find a lot of online resources. You may find more adventurous people looking into Onion Omega 2 or C.H.I.P., far less in BeagleBone Pocket.

Then you have the language-centered developers that feel more comfortable when finding a small board supporting their favorite language (Javascript, Python, Basic) for hardware-related projects.

A cheap, pre-assembled STM32F4 may find its purpose as a high-end MCU/FPU/DSP with lots of IOs, for applications like flight or 3D printer controllers, I think.

And in our case, the most interesting is not the destination, it is the journey! I enjoyed this project because I learned a lot while working on it, and I hope this is the case for others, too.

For what it’s worth, I’d be interested in attempting assembly and test. I’ve done manual SMT work before, it’s tricky to say the least, but not outside of the realm of possibility. The trick with a QFP is to drown it in flux, and allow shorts to happen, but draw solder away with the capillary action of the iron. The smaller parts are not quite so bad. I think if you have got this far, there is no turning back.

[electrobling – Sun Feb 04, 2018 10:15 pm] –
The trick with a QFP is to drown it in flux, and allow shorts to happen, but draw solder away with the capillary action of the iron. The smaller parts are not quite so bad. I think if you have got this far, there is no turning back.

I have done the same trick with QFP before, and didn’t have any problem. I think the worst for me is holding small components in place when they are all slick from the flux…

I agree the the previous postings about theoretical cost of other boards, vs what most of us actually have to pay for them.

Locally, to get a RPi zero, prices are nearer $15 USD
e.g. This is probably the cheapest I can get hold of
https://core-electronics.com.au/raspber … eless.html

ESP32 are around $10 USD direct from China (including shipping)

Boards like the BP and MM (and the ESP8266) etc are the only ones I can get in the $2 – $3 range

Victor

I’ve ordered almost all the parts for 5 boards. So if you haven’t ordered them yet then please put me down for 5 or 6.
These are on a slow boat from China so they won’t be here anytime soon! I will order the remaining ones from Mouser this week. Let me know if you would like me to get some for you. The prices for the AP2114HA-3.3TRG1, LQW2BASR47J00L and MCP73812T-420I/OT seemed better there and the shipping can be covered by another order I am placing. Only the first of these is required but we will need to test the optional parts.

Being a mathematician, I don’t have the experience to comment on the layout but I’ll try to review the schematic.
I don’t have a reflow oven but do have a cheap rework station and stereo microscope so I think assembly will be fine … but slow.

I have been mainly playing with some baremetal and HAL/LL/CMSIS programing on the STM32L4. So I should look at the F4 boards I have more seriously. Is the idea to work with the STM32GENERIC core ?

Eric

[victor_pv – Sun Feb 04, 2018 10:48 pm] –

[electrobling – Sun Feb 04, 2018 10:15 pm] –
The trick with a QFP is to drown it in flux, and allow shorts to happen, but draw solder away with the capillary action of the iron. The smaller parts are not quite so bad. I think if you have got this far, there is no turning back.

I have done the same trick with QFP before, and didn’t have any problem. I think the worst for me is holding small components in place when they are all slick from the flux…

For a small component, I apply the least amount of solder I can to only one pad. Then I place the component with tweezers and heat that end until it sticks. I go to the other end and make a proper solder join. Then I return to the original end and fix the bad join with a decent amount of solder.

[electrobling – Mon Feb 05, 2018 11:27 am] –
For a small component, I apply the least amount of solder I can to only one pad. Then I place the component with tweezers and heat that end until it sticks. I go to the other end and make a proper solder join. Then I return to the original end and fix the bad join with a decent amount of solder.

+1 .. also good tweezers are a must.

I don’t necessarily mean expensive ones, simply ones that have well defined tips that are parallel to each other and small enough not to be too clumsy to handle the component. I have filed away the tips of some cheap tweezers and carefully hammered them flat and parallel to make them more serviceable.

They tend to need some adjusting as time goes by due to the heat from the soldering iron.

Having the eyesight of a 20 year old would also help, but I’ve checked on ebay, and nobody appears to be selling this.

I would be interested in trying to build several boards, but I do have the problem of parts. I always order absolutely everything from China, as the shipping costs from the U.S. to Canada are astronomical because the companies like Mouser decline to use the post office. Also the Chinese New Year is upon us soon, and no orders to N.A. will be shipped for an entire month. That might mean a 2 month delay to get parts, assuming that I can source them.

[ahull – Mon Feb 05, 2018 11:42 am] –

[electrobling – Mon Feb 05, 2018 11:27 am] –
For a small component, I apply the least amount of solder I can to only one pad. Then I place the component with tweezers and heat that end until it sticks. I go to the other end and make a proper solder join. Then I return to the original end and fix the bad join with a decent amount of solder.

Having the eyesight of a 20 year old would also help, but I’ve checked on ebay, and nobody appears to be selling this.

Thank god i got my eyes from the good side of the family XD
my sisters have to wear glasses, while i’ll probably have eagle eyes till i’m 60 ^^

[racemaniac – Mon Feb 05, 2018 12:46 pm] –

[ahull – Mon Feb 05, 2018 11:42 am] –

[electrobling – Mon Feb 05, 2018 11:27 am] –
For a small component, I apply the least amount of solder I can to only one pad. Then I place the component with tweezers and heat that end until it sticks. I go to the other end and make a proper solder join. Then I return to the original end and fix the bad join with a decent amount of solder.

Having the eyesight of a 20 year old would also help, but I’ve checked on ebay, and nobody appears to be selling this.

Thank god i got my eyes from the good side of the family XD
my sisters have to wear glasses, while i’ll probably have eagle eyes till i’m 60 ^^

All bets are off when you hit 50
I had pretty much perfect vision till I was in my late forties, I now use reading glasses and complain about the writing on packaging, but I can still spot an eagle at 1000 yards.

i almost have an impulse to join a group purchase, e.g. the boards
on the record i’ve 2 castellated nrf51822 boards
https://www.ebay.com/itm/NRF51822-YJ-14 … 2396174917
after receiving them i’m dumbfolded as i’m not sure how i’m going to solder them, smt really takes some skill, it certainly isn’t as simple as those 0.1 inch through hole boards

[ahull – Mon Feb 05, 2018 3:09 pm] –

[racemaniac – Mon Feb 05, 2018 12:46 pm] –

[ahull – Mon Feb 05, 2018 11:42 am] –
Having the eyesight of a 20 year old would also help, but I’ve checked on ebay, and nobody appears to be selling this.

Thank god i got my eyes from the good side of the family XD
my sisters have to wear glasses, while i’ll probably have eagle eyes till i’m 60 ^^

All bets are off when you hit 50
I had pretty much perfect vision till I was in my late forties, I now use reading glasses and complain about the writing on packaging, but I can still spot an eagle at 1000 yards.

60 is maybe a bit optimistic indeed, it’ll be the same as my mother i guess, once past 50 hope for the best, but that gives me about 20 years of not needing glasses at the least :p

60 is maybe a bit optimistic indeed,
The picture at the bottom shows the minmum seeing distance versus age.
The worst decrease is between the age of 45 and 50.

I did follow this topic since do have an interest for few boards, however instead of joining group buy I will order the boards myself, the postage will kill all the economy with group buy…
What I want to ask if you guys considered panelization, most vendors will offer 100×100 min.5 boards on same price as smaller ones, so may be we may benefit some cost down from panelization?
Squonk, is a big deal for you to panelize the design for say 100×100 PCB?
I know some vendors do not accept panelization and would charge you more (allpcb.com as an example), however there are plenty of them who just don’t care, and from well known vendors seeedstudio.com seems to be the one…

Right now, there is no economic goal with this batch, we just want to make them work

I did a pre-version from EagleCAD as a 100 mm x 100 mm panel with 5 boards (4 in one direction, 1 perpendicular) using SeeedStudio Fusion, I ended up paying $15.05 for 10 panels (50 boards), but I had to wait for 3 weeks before receiving them.


viewtopic.php?f=19&t=2633&p=38319#p38319

As we wanted to test these asap, we went through AllPCB with free and fast DHL delivery for $26, we should receive them this week or beginning of next week.

If you are EU or US, we can ship you some bare boards for <$2 using snail mail.

[parasole – Wed Feb 07, 2018 8:24 am] –
I did follow this topic since do have an interest for few boards, however instead of joining group buy I will order the boards myself, the postage will kill all the economy with group buy…
What I want to ask if you guys considered panelization, most vendors will offer 100×100 min.5 boards on same price as smaller ones, so may be we may benefit some cost down from panelization?
Squonk, is a big deal for you to panelize the design for say 100×100 PCB?
I know some vendors do not accept panelization and would charge you more (allpcb.com as an example), however there are plenty of them who just don’t care, and from well known vendors seeedstudio.com seems to be the one…

indeed, if we want to go for bigger batches, and don’t care for it taking a few weeks, making a panel and then ordering it via seeed/dirtypcb/… is cheaper, but that’s not our current goal
if you need panelized gerbers, let me know, and i’ll create some (with mouse bites in between the panels)

The status shows “shipped”

Update:
Got a text from DHL, boards will arrive on Friday

[racemaniac – Wed Feb 07, 2018 8:58 am] –
if you need panelized gerbers, let me know, and i’ll create some (with mouse bites in between the panels)

Thanks for your offer racemaniac, gladly would receive the panelized gerbers…

[parasole – Thu Feb 08, 2018 8:56 am] –

[racemaniac – Wed Feb 07, 2018 8:58 am] –
if you need panelized gerbers, let me know, and i’ll create some (with mouse bites in between the panels)

Thanks for your offer racemaniac, gladly would receive the panelized gerbers…

I’ll do my best to create some tonight

[Squonk42 – Wed Feb 07, 2018 8:54 am] –
If you are EU or US, we can ship you some bare boards for <$2 using snail mail.

Yes Squonk42, I would take two boards, I may solder quickly one board (using STM32F405RGT6) and do a basic check exept for card reader which I don’t have yet…

[parasole – Thu Feb 08, 2018 9:06 am] –

[Squonk42 – Wed Feb 07, 2018 8:54 am] –
If you are EU or US, we can ship you some bare boards for <$2 using snail mail.

Yes Squonk42, I would take two boards, I may solder quickly one board (using STM32F405RGT6) and do a basic check exept for card reader which I don’t have yet…

If you are located in EU, I can send you some boards as soon as I receive them, along with some microSD Card connectors, I have a few of them. Please send me your address as PM.

Yes it is in EU…

[victor_pv – Wed Feb 07, 2018 1:36 pm] –
The status shows “shipped”

Update:
Got a text from DHL, boards will arrive on Friday

Mines are in Pudong International Airport (Shanghai), handled by TNT, but no ETA yet.

[Squonk42 – Thu Feb 08, 2018 9:48 am] –
Mines are in Pudong International Airport (Shanghai), handled by TNT, but no ETA yet.

Let’s hope they will ship them out before weekend, next week the whole country enter to spring festival holidays…

Would anybody need it (but i’d advise to be a bit patient until we tested these boards), here is a panelized version of the bluepill f4 gerbers

[parasole – Thu Feb 08, 2018 1:55 pm] –

[Squonk42 – Thu Feb 08, 2018 9:48 am] –
Mines are in Pudong International Airport (Shanghai), handled by TNT, but no ETA yet.

Let’s hope they will ship them out before weekend, next week the whole country enter to spring festival holidays…

Mine arrived at Liege euro hub at midnight CET, so they made it out of China before CNY!

But I doubt I will receive them today, more likely on Monday.

I received the PCB from AllPCB today, see this post!

My boards arrived yesterday.
I have to place an order for a few components that I am missing and then can reflow some.
If anyone wants to start trying with the bare boards, send me a PM with your address.
I would appreciate a paypal pay of $3 for 5 boards to offset cost ($1 stamp+envelope $2 for boards).
F103 and F405 MCUs should fit and use all pins, other MCUs may loose Pin PB11 (F411 for example), so if you want to use a different MCU check the datasheet for differences with the F405 series.

When I get the crystals and buttons from Mouser I can reflow my first.