Older versions of FreeNAS would email periodic status reports, however the newer 9.x versions no longer do this. FreeNAS now only sends emails when something strange or bad happens. It makes sense – lots of “everything’s fine” emails tends to…
Building a Do It Yourself NAS
Introduction NAS (Network Attached Storage) devices, also known as a home server, are pretty common these days. They’re great for having a central point to store files; as a media server for holding photos and home movies; as a place…
STM32F2xx / STM32F4xx DMA Maximum Transactions
It’s funny how a topic as apparently mundane as the DMA controllers on the STM32F2xx and STM32F4xx processors can be such a can of worms. I’ve already provided 2 postings on the subject, here and here, and now we have…
STM32F2xx / STM32F4xx SDIO Interface Part 2
Here’s the link to Part 1. A very significant limitation with the STM32F4xx family (STM32F405 / 407 / 415 / 417) is that fully a third of its internal RAM is inaccessible to the DMA controller. Of the 192 kB…
If Apple Wins We All Lose
I’m not generally one to repost articles and links to articles – you won’t find much of that on my blog. Nor am I particularly pro-this or anti-that when it comes to technologies, brands, companies, etc. I have Apple products…
STM32F2xx DMA Controllers Part 2
The discussion around the STM32F2xx and STM32F4xx DMA controllers is becoming a bit too large for a single posting, so here we are with Part 2! Clearing a DMA Interrupt In theory this is very simple – in practice not…
Do It Yourself Signal Generator Probe
Some time ago I built a signal generator, which is a reasonably handy bit of equipment. But I was periodically frustrated with not having a suitable probe to easily inject a signal into a circuit. The standard BNC – BNC…
Class 10 SD Card – Or Not?
Recently I purchased a Class 10 SD Card from a major retailer. I was very excited – now I have a fast card for testing. Here’s my new baby: Note the 10 in the part-circle indicating the speed. For those…
STM32F2xx SDIO SD Card Interface
The STM32F2xx has a great SD Card interface. It’s a true 4-bit parallel interface, and in general it works pretty well. I have come across a few, fairly minor but still significant, considerations when using the interface that I thought…
STM32F2xx Digital Camera Interface (DCMI)
I’m using the STM32F2xx DCMI port to receive data from an CMOS image sensor. There aren’t too many Cortex-M3 or M4 parts which have this ability natively; the STM32F2xx is a rare breed. It’s a very nice feature. Along the…