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printf for embedded systems

I'm publishing a printf library for embedded applications. I know, does the world really need yet another printf? Probably not, but this one is a little different from all the others that I found. For starters, it doesn't even do printf! It has one primary function, snprintf(), which is exactly like the standard library call and generates a string that is bounded so it can't overflow its buffer. In a memory constrained system there's always the challenge of how big a buffer to allocate to snprintf; large enough to hold the output string but not wastefully large. You can pass...


ee203 Debug Commands

There are two sets of menus accessable to the user in the ee203, the command menu that you see when you run the application, and a second debug menu that is useful for troubleshooting or just entertainment. When you are in the normal command menu, the prompt is CMD> To toggle between menus, enter the [M] command. The prompt for the debug menu is DBG> [H] will give you the monitor help with a list of available commands: [C]ur Src is the most useful debug command. This allows you to directly control the internal current sources used for self-calibration. There...


ee203 Operating Modes - Bootloader vs. Application

The ee203 has an integral bootloader to allow field updates of the firmware. Updates are performed by dragging a firmware image onto a USB flash drive. For performance reasons the flash drive does not appear when the bootloader is not active. The ee203 has two operating modes: bootloader and application. Bootloader mode allows the firmware to be updated, and application mode is the normal RTCM functionality. On power-up, when the USB cable is connected to the PC, the voltage at the SUPPLY terminal is sampled. If the voltage is less than 1.5V, the bootloader is launched, otherwise the application is...


How to use the [S]cale command

Like many of us, I find it more difficult to wrap my head around logarithmic values than linear values. This makes the [S]cale command on the ee203 very seductive. It outputs the measured current on a linear rather than logarithmic scale. Unfortunately, seductive is not always practical (see, for example, women). A linear scale may or may not be useful to you. Let me explain. One of the things that makes the ee203 such a useful device is its huge dynamic range. 6 orders of magnitude is pretty amazing for such an inexpensive device. Practically speaking the only way to...


Cuba Trip

Not technical or related to our products in any way, but I know that Cuba fascinates lots of people, so I thought I would post a video. This is a time-lapse of a drive through Havana in July of 2017. The route is from Havana Vieja (Old Havana) then along the Malacon (Seawall). You can see the US Embassy on the left at around 0:15. As you can see, there are still a lot of 50's era American cars plying the road, although they are becoming fewer in number as more modern cars are imported.

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