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1. 

   samtal
   Member

   After almost two years away from Maple, I started an old-new project.
   In the meantime, I had the chance to look at Arduino Mega, and even ported a simple Maple-r5 project to the Mega, which worked nicely.

   I now have to decide whether to build the new project with Maple or with Arduino.
   The cons for Arduino: (1) EEPROM that enables very large number write / read and (2) The use of one USB port for everything (I only need one!).
   The Maple pro's are mainly its speed (32 bits, 70 Mhz).
   (Another project with 10 12-bits Analog with DMA could only be done on the Maple)

   One more thing: I have some doubts about Maples hardware reliability: I lost 4 Maples-r5 by connecting an external 9V Power-supply, for no apparent reason.
   As soon as I connected the PS (any), the external PS serial diode went up in smoke, and a permanent short to ground persisted, even after removing all components from the board).
   Being an experienced electrical engineer, I tested everything I could think of, like jumpers, ground loops, spikes, over-voltage, but could not find the reason.

   I would like to read LeafLabs' or any other experts' comments on my observations before I make my decision.
   Thanks,
   samtal

   Posted 1 year ago #
2. 

   gbulmer
   Moderator

   samtal - I don't work for LeafLabs, and I don't call myself an expert. However, let me offer some views.

   Clearly I like STM32F and Maple. However, I am ready and willing to use Arduino (I am using it on a project at the moment).

   So it may be that some simple, clear differences are all the criteria needed to make a rational choice.
   If an Arduino does everything the project is likely to need, you are happy to use its libraries and IDE, and the end-user is happy or takes your recommendation, then it seems a pretty straightforward decision to me.

   How big is the data that you are storing in EEPROM? Might it all fit within the STM32F's battery-backed RAM area? IIRC is much faster to write a few bytes into that than EEPROM. I can't think of any other decision criteria based on the project description.

   Some of your feedback, and others, about the Maple's power supply went into the Community Maple re-designs.

   Some of the specific changes in Orone-mini are intended to provide a more robust power supply (at github: https://github.com/gbulmer/openstm32hw/tree/master/Orone-mini-v0 )
   It has a polyfuse protecting the USB host, ESD protection, and a larger digital-supply voltage regulator with more headroom.

   I am surprised that the PS diode failed, and resulted in a permanent short to ground. I don't think I've seen that failure-mode. If I understood your comment, you removed the PS diode, and the short-to-ground persisted; is that accurate?

   Posted 1 year ago #

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