Flash Options
Posted: Sat Aug 03, 2019 12:56 pm
Hi All,
I'm a new MicroPython forum member but have been using the Pyboards for a while (and other IoT projects).
I'm trying to develop an environmental data logger for a school that is going to be deployed for up to 10 years collecting data and reporting it to a web server over the mobile networks. The files I've written are getting fairly big (350KB) and I anticipate I may have to update firmware (so there could be two file sets) and store data files occasionally on the device so am looking for 2MB+ of storage. I want to keep cost as low as possible as I plan to make quite a few of these and reliability is important as it will be difficult to replace faulty parts once deployed.
What is the easiest way of adding flash memory to the STM M4 range of chips? As I see it I have the following options:
-By a 2MB STM M4 chip (eg STM32F427) that costs around £11.22 compared to £6.00 for the cheaper chip in the Pyblite - v reliable but quite expensive, need to port Micropython to the F427 and doesn't have loads of space.
-Use a basic SD card - lots of space, easy to develop and can be cheap, but I have concerns around reliability if it's going to be deployed for years.
-Use an industrial SD card - lots of space, easy to develop and reliability should be better than basic SD card, but they start at £10 so v expensive.
-SPI flash - plenty of space, very cheap (£0.50) and very reliable, but it isn't readily supported by the looks of it so would need to do a fair bit of development in an area I don't know much about.
Does anyone have any thoughts on the above or other ideas? Any help is appreciated.
Thanks,
Marc
I'm a new MicroPython forum member but have been using the Pyboards for a while (and other IoT projects).
I'm trying to develop an environmental data logger for a school that is going to be deployed for up to 10 years collecting data and reporting it to a web server over the mobile networks. The files I've written are getting fairly big (350KB) and I anticipate I may have to update firmware (so there could be two file sets) and store data files occasionally on the device so am looking for 2MB+ of storage. I want to keep cost as low as possible as I plan to make quite a few of these and reliability is important as it will be difficult to replace faulty parts once deployed.
What is the easiest way of adding flash memory to the STM M4 range of chips? As I see it I have the following options:
-By a 2MB STM M4 chip (eg STM32F427) that costs around £11.22 compared to £6.00 for the cheaper chip in the Pyblite - v reliable but quite expensive, need to port Micropython to the F427 and doesn't have loads of space.
-Use a basic SD card - lots of space, easy to develop and can be cheap, but I have concerns around reliability if it's going to be deployed for years.
-Use an industrial SD card - lots of space, easy to develop and reliability should be better than basic SD card, but they start at £10 so v expensive.
-SPI flash - plenty of space, very cheap (£0.50) and very reliable, but it isn't readily supported by the looks of it so would need to do a fair bit of development in an area I don't know much about.
Does anyone have any thoughts on the above or other ideas? Any help is appreciated.
Thanks,
Marc