STM32F103 vs GD32F103 round 1: Solderability

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Sjaak writes:

I locked myself into the basement with a couple of PCBs, chips and fresh flux for a couple of days. For the STM32F103 vs GD32F103 challenge I needed to have two identical boards with a different microcontroller. As far as I could judge both chips are legit and not counterfeits as we bought both chips from (different) reputable sellers. The used chips are GD32F103CBT6 and STm32F103CBT7. The STM32F103CBT7 is the industrial rated part of the STM32F103CBT6 and is identical except for the temperature range.

More details at smdprutser.nl.

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Measuring USB power cable voltage drop with my DC load

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Dr. Scott M. Baker published a new build:

This started when one of my raspberry pi projects failed due to voltage drop on the USB power cable that I was using, so I set out with my power supply and DC Load to measure the voltage drop of various cables that I use in my lab

More details on his blog here.

Check out the video after the break.

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#FreePCB via Twitter to 2 random RTs

BP

Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week:

  • Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch it every Sunday, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs will be your friend for the weekend

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Check out how we mail PCBs worldwide video.
  • We’ll contact you via Twitter with a coupon code for the PCB drawer.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.

We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.

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Multicolor signal light with beeper

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Multicolor signal light with beeper for ROS by Gal Pavlin

When debugging algorithms in an autonomous vehicle a light that can show algorithm state in real time was proven to be effective for easier debugging and additional insight to what is going on in the code.
Because all existing signal light were either to bulky or too expensive we decided to build our own. It was actually quite simple with few key elements:

  • 3x RGB LED strip
  • STM32F0 microcontroller with native USB support
  • Beeper

Via Mare & Gal Electronics.

Check out the video after the break.

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Troubleshooting tips: Failed debugging with GDB

problem-occured-version

Erich Styger writes:

Three years ago I published “Debugging Failure: Check List and Hints” and unfortunately this article is one of the most popular ones: obviously debugging problems are very common. Debugging with GDB works usually fine, but if things are failing, then it can be hard to find the cause for it. Recently I have been asked to check some failures, so here are two more hints about what could go wrong…

More details at MCU on Eclipse blog.

 

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App note: Measuring inrush current

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Inrush current evaluation from Aimtec. Link here

In AC/DC power converters beyond a few watts, during the initial application of power an excessive inrush current will flow when the input capacitors are suddenly charged. If unhindered the inrush current can easily exceed 50 A at the peak of the AC cycle and severely stress the converter’s fuse and input rectifiers, thereby significantly reducing the reliability and life expectancy of the modules. Universal power supplies (supplies which accept a wide range of input voltages) are particularly susceptible to high inrush current since their input capacitors must be large enough to handle line voltages as low as 110 VAC, as well as voltages as high as 305 VAC at start-up. In these environments, a power-supply failure or a tripped circuit breaker can be inconvenient at best, and expensive or dangerous at worst.

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Free PCB Sunday: Pick your PCB

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We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB. You get unlimited free PCBs now – finish one and we’ll send you another! Don’t forget there’s free PCBs three times every week:

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Be sure to use a real e-mail in the address field so we can contact you with the coupon.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.
  • PCBs are scrap and have no value, due to limited supply it is not possible to replace a board lost in the post

Be the first to comment, subscribe to the RSS feed.

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App note: Pulse width modulation (PWM) vs. Analog dimming of LEDs

an_aimtec_led_dimming

App note from Aimtec on dimming LEDs. Link here

With the phenomenal growth of the LED lighting market, there has been a natural growth in demand for highly efficient and controlled LED drivers. Applications from ‘smart’ street lights, flashlights, digital signage and many others require not only highly regulated currents, but in many cases dimming capability in order to sustain the energy efficient scheme and end use flexibility behind LED design.

As there are several ways to achieve dimming of an LED, we describe here the main methods that are used to provide dimming for LED’s from a switch mode LED driver.

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Free PCB coupon via Facebook to 2 random commenters

BP

Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three times every week:

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • We’ll contact you via Facebook with a coupon code for the PCB drawer.
  • Limit one PCB per address per month, please.
  • Like everything else on this site, PCBs are offered without warranty.

We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.

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STM8 Microcontrollers

Hardware

Here’s a three-part series of posts by Shawon Shahryiar detailing the STM8 microcontrollers:

STM8 microcontrollers are 8-bit general purpose microcontrollers from STMicroelectronics (STM). STM is famous mainly for its line of 32-bit ARM Cortex microcontrollers – the STM32s. STM8 microcontrollers are rarely discussed in that context. However, STM8 MCUs are robust and most importantly they come packed with lots of hardware features. Except for the ARM core, 32-bit architecture, performance and some minor differences, STM8s have many peripheral similarities with STM32s.

Read the full post at Embedded Lab’s blogPart 1 and Part 2 are also available.

Check out the video after the break.

 

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