https://jeelabs.org/projects/bento/ Recent content in Bento on JeeLabs Hugo -- gohugo.io en-gb © 2019 Jean-Claude Wippler Tue, 09 Jul 2019 00:00:01 +0200 https://jeelabs.org/2019/disco-l053-2/ Tue, 09 Jul 2019 00:00:01 +0200 https://jeelabs.org/2019/disco-l053-2/ The previous article mentioned that the “Disco-L053” board includes a complete current measuring circuit, which can handle a range of nearly six decades. So here is a brief description of how to actually use it that way. First off, on the hardware side, two minor adjustments need to be made to the board: Connecting the L053’s TX pin to the on-board ST-Link. Connecting the Device Under Test to the board. https://jeelabs.org/2019/disco-l053/ Mon, 08 Jul 2019 00:00:00 +0200 https://jeelabs.org/2019/disco-l053/ It turns out that there’s a nice way to measure current consumption with a commercial board by ST Microelectronics. It’s called the 32L0538-DISCOVERY, but for brevity and consistency I’m going to call it the “Disco-L053” from now on: This is one of a long range of “Discovery” evaluation boards by STM, and as you can see it even has a touch slider and 172x72 pixel ePaper display. But the main feature for our purposes is that it includes a very nice current measuring circuit, which is used by some demo software to demonstrate that the main L053 µC on the board draws 42 µA in low-power run mode at 131 KHz and that it has a “stop” mode which draws a mere 400 nA. https://jeelabs.org/2019/pio-cli/ Thu, 04 Jul 2019 00:00:19 +0200 https://jeelabs.org/2019/pio-cli/ Software development for embedded microcontrollers requires – as a minimum – a text editor to enter and tweak source code, 2) a “toolchain” to compile and link the code into a firware image suitable for the selected µC, and 3) an upload mechanism. The best-known example of this is no doubt the “Arduino IDE”, an Integrated Development Environment which, ehm … integrates all of the above into a single (open-source and free) product. https://jeelabs.org/2018/low-power-l031/ Fri, 28 Dec 2018 00:00:19 +0100 https://jeelabs.org/2018/low-power-l031/ The exploration into low-power sleep modes continues. An STM32F103 draws just 3 µA in standby mode, but that’s not the end of the story. The STM32L0xx µCs are more modern and even lower-power. So I just had to try the same thing again with an STM32L031: This is a small, but still hand-solderable, TSSOP-20 package. There’s even a TSSOP-14, if you’re willing to switch to L011 (2K ram instead of 8K). https://jeelabs.org/2018/current-measurement/ Tue, 11 Dec 2018 11:34:11 +0100 https://jeelabs.org/2018/current-measurement/ An F103 sleeping with a current consumption of 3 µA is very impressive. This translates to about 7 years of “run” time on a CR2032 coin cell (although not doing anything useful). That is three orders of magnitude lower than the ≈ 5 mA of standard run mode at 8 Mhz. And it’s very much in line with the capabilities specified in the STM32F103 datasheet: Our demo actually exceeds the specs given in the table above, which is down to 3. https://jeelabs.org/2018/standby-current-f103/ Mon, 10 Dec 2018 03:34:11 +0100 https://jeelabs.org/2018/standby-current-f103/ I’ve always kept an interest in low-power explorations, most of which I did many years ago. First there was the ATmega328, then the LPC824, and finally on the STM32L052. One reason, is that I find it fascinating to see a µC drop multiple orders of magnitude in power consumption, yet still have enough wits to wake up, periodically or via an I/O pin. It’s hard to overstate the effect this can have on real-world devices: letting a circuit drop to µWatt power levels, i.