Electron Carrier Board


#111

@RWB, @chipmc, you may want to read through this five part series on FSMs. I haven’t had time to look at their state chart drawing tool (Yakindu) yet. :wink:


To FSM or not to FSM (Finite State Machines discussion)
Delay in sensing temperature locks up Photon
#112

@peekay123,

Thank you for the link. I like the way that this tool links the state diagram to code-generation. I will see if I can get a copy and give it a try.

Thanks,

Chip


#113

The overall concept of FSM makes sense to me but I can also say that I can relate to this guys comment at the bottom of that article :slight_smile:


#114

excellent observations!

Couple more:
4) when transitioning from state X to state Y you can publish an event or log a message, so you know exactly when (and perhaps why) a transition is triggered.

  1. if you use an FSM library, like this one ported from Arduino, you have access to state enter and exit functions that can be useful to set things up while entering/leaving a state. It also tells you how much time the FSM has been in that state,

  2. when you start coding with FSMs in mind you don’t really know what you are doing but you try it and most probably you’ll stick with it since you’ll like it so much

  3. if your code has a variable called state or status then is very probable that you are using an FSM but you did not know.

  4. the two links I had fun reading and finally got me into using FSMs:

this one:
https://www.skorks.com/2011/09/why-developers-never-use-state-machines/

and this one:

I’d say try one once and see, you won’t regret :wink:


To FSM or not to FSM (Finite State Machines discussion)
#115

@gusgonnet, great comments and links! I’m a big proponent of FSM’s especially when working with FPGA design. Maybe it’s worth starting a new topic with just this FSM stuff.


To FSM or not to FSM (Finite State Machines discussion)
#116

good idea, done!


#117

All,

I have finished documenting this carrier board and publishing it on HAckster.io. You can see it here: https://www.hackster.io/chipmc/particle-electron-carrier-for-outdoor-iot-applications-40ed52

Hope this is helpful.

Chip


#118

Traffic data for the parks seems like a great idea and very useful to them.

How did you approach them about doing this? What has their feedback been about this new data resource?


#119

Hi @chipmc,
I’m going to get a board or two, is there a resource you know of that will make and populate these?
I’m not sure I’m up to the task of the SMT assembly
J


#120

@jimbol,

Great news. I can help you with the assembly or get a friend of mine to do it. Because I am doing these one at a time, it takes me about an hour to assemble and test a board. Send me a DM and we can see if we can agree to a fair deal.

Thanks,

Chip


#121

@peekay123 and @Suprazz, do you happen to have any sample code you wouldn’t mind sharing with me for SPIFFS beyond what’s in https://github.com/Suprazz/downloadFile?

I have Micron SPI NAND flash which says its interface is the same as for SPI NOR; maybe that’s already the answer to my problem described below but I am hopeful that I can use SPIFFS or another Particle-ported SPI Flash library. Do you think I stand a chance at getting SPIFFS (or anything) to work on SPI NAND with my Electron? I really like the idea of using embedded FRAM, flash, EEPROM for mechanical resilience as you’ve pointed out before, @peekay123, but need something in the 100+ MB range.

Following this thread and your response to my post a few weeks ago here, I have tried heading down that route but can’t yet get anything other than “Flash init error”. I set my chip select pin in the application.ino using if (flash.begin(D2)) as I’m not using the default CS; all other SPI defaults remain (SCK => A3, MISO => A4, MOSI => A5 for my Electron).

Thanks in advance for any pointers you’re able to offer!


#122

@supscientist, there are key differences between NAND and NOR flash devices. SPIFFS clearly states that it is designed for NOR type flash. However, you can test with the Micron device to see if it works. What device are you proposing to test (part number). Did you modify the Adafruit_TinyFlash.h file with the correct size and IDs? The “flash init” error is specifically related to the Adafruit_TinyFlash code so you need to focus there.


#123

Thanks so much for your help, @peekay123. Just went down the rabbit hole of trying to update particle-cli at its suggestion and lost an hour trying to troubleshoot that, but we’re back! Though it appears I have to compile in the cloud twice using Particle Dev in order to get a new .bin file… I may post about that elsewhere shortly.

Yes, I have seen that SPIFFS is meant for NOR so this might not be a wise approach on my part I’m just really hoping I can find some sort of truly embedded large storage (~1 Gb or bigger) solution.

The part is a Micron MT29F1G01ABAFDSF and I have set Adafruit_TinyFlash.h defines to

#ifndef CHIP_BYTES
    #define CHIP_BYTES       64L * 2176L // 64 pages * 2176 bytes
#endif
#ifndef MAN_ID
#define MAN_ID 0x2C
#endif
#ifndef DEV_ID
#define DEV_ID 0x14 
#endif
#define PAGE_SIZE 2176
#define CMD_ID           0x9F

following the datasheet

I can now get through that flash.begin(D2) call so, at the very least, I’m reading the MAN_ID and DEV_ID. I’m now getting to errno -10010 in test_spiffs() which I see is a SPIFFS_ERR_BAD_DESCRIPTOR. Can’t get past that but I’m trying to play with the CMD_* options in Adafruit_TinyFlash.h. I’m beginning to more deeply appreciate some of the NOR vs. NAND flash differences now as well; maybe I should switch to NOR… Anyway, thanks again, @peekay123!


#124

You should read the SPIFFS docs. The author clearly states the library is not designed for large storage (ie > 128MB) since it is designed for small, resource constrained systems. Besides, performance is greatly affected by the storage size.
For storage that large, you will need to consider a microSD but with a robust locking socket.


#125

Yes, I know, maybe I shouldn’t have used the word “large” which is relative and perhaps meaningless in this context. I have read them. 1 Gb = 128 MB so I thought I’d be fine but maybe the NAND vs. NOR differences will get me here. Micron also sells a 1 Gb serial NOR chip which has a command set closer to what I see in SPIFFS so I’ll test that next just hoped I could kludge it together with NAND & SPIFFS.

It’s a shame that with so many great hardware options there isn’t a software option for larger SPI flash yet! Oh well. Thanks for the really quick and insightful responses.


#126

Other than the higher cost what’s the problem with uSD cards? They have an almost unlimited capacity and are super quick. Plus there is already the working SDFat library for them to get you rolling.


#127

This is an underwater device and the whole PCB needs to be potted in epoxy under pressure. I’m very concerned that epoxy will squeeze in between metal contacts and leave us with failed memory cards and useless products. Maybe it’s just paranoia.

Some of the hacky ways of soldering/reflowing uSDs onto PCBs look promising for small quantities but I was hoping to find a production-scale solution and SPI flash looks sooo close to what I wanted.

I hear you and @peekay123 on going with a solution that just works, though.


#128

I had a small batch of these board made at MacroFab. If anyone wants one, they are $50 each.

Thanks,

Chip


#129

They look perfect!

I just uploaded a large board to their site to see what I’m looking at pricing wise and it’s not cheap but well worth the cost considering they are fine pitch parts that I would probably not get placed or reflowed correctly.

How quickly did they get them produced for you? How many did you have made?

Feels good to have professionally manufactured designs delivered to your doorstep, doesn’t it :slight_smile:


#130

@RWB,

It was to have taken 21 days but mine got caught up in the Christmas break.

For this first run, I had 20 made but should have done more. Their prototype service only runs to 50.

I think it is quite a bargain when you consider your time and the prospect of rework.

Chip