MicroCrystal RV-8803 – A Really Accurate RTC June 17, 2019- RTC chips traditionally were the domain of Maxim and NXP. Switzerland-based MicroCrystal recently made quite a buzz with its RV-8803, which offers simple integration, an I2C interface and extreme accuracy. Let us start out by looking at a system overview. Figure one shows how this I2C RTC is made up internally – interested observers note […] Analog Devices’ LTM2887 – If a Digital Bus Needs Galvanic Isolation June 15, 2019- In theory, digital buses are intended to connect things to one another. Sadly, one sometimes wants but a logical connection – in many cases, galvanic isolation helps out. Should you ever feel like isolating very fast buses, definitely give the LTM2887 a chance. From a technical point of view, Linear Technologies attempt at entering the […] AVAGO APDS-9008 or APDS-9005-020 – Keeping an Eye on Ambient Light June 14, 2019- Recent times saw quite a bit of interest for part numbers such as the APDS-9008 or APDS-9005-020 – they are a very interesting type of ambient light sensor. One of the oldest questions in regards to light sensors involves their spectral sensitivity. If a part is to output but one voltage level, the conversion between […] STMicroelectronics’ LIS2DH12 – Low Power Motion Sensing June 12, 2019- Apple’s iPhone introduced gyroscopic sensors to a wider range – before that, accelerometers were not commonly found in consumer hardware. STM sells excellent parts which, however, get little media attention – time to take a look at the LIS2DH12. Integrating the part into your circuit as an MPU6500 alternative or MPU9500 alternative is not difficult. […] Panasonic AMG8833 – FLIR for cheap June 7, 2019- FLIR made infrared thermal sensors cool – sadly, their parts are all but cheap (and suffer from export control problems). Panasonic’s Grid-EYE family is a low-resolution alternative which comes at significantly lower cost. From a technical point of view, Panasonic’s image sensor could not be simpler. We are looking at an 8×8 sensor with an […] DipTronics DTS-62R-V – Small Switch, Very Big (and Very Cheap) June 5, 2019- When yours truly was but a lowly cadet, various US manufacturers produced (pricey but quite reliable) switches. Chinese vendors recently started to catch up – seeing the DTS-62R-V top our customer interest list shows that the run stage of the crawl-walk-run cycle is reached. DipTronics has been around the Asian switch market for ages, exhibiting […]
When the Raspberry Pi Foundation introduced the Raspberry Pi Three…
When the Raspberry Pi Foundation introduced the Raspberry Pi Three, many a developer was fascinated by the integrated Wi-Fi module. Sadly, practical performance was not quite as good. Let’s find out if the next generation brings any improvement.
The most important thing first: the Raspberry Pi 3B+ can now connect not only to 2.4 GHz networks but also to ones operating in the 5 GHz band. This means that you can escape congested areas more easily, albeit at the price of shorter range.
Performing actual Wi-Fi performance tests is a bit difficult – let us stick to using Ping and iperf, yielding the results shown in the table. The Raspberry Pi 3B had lower ping latencies, but the new model achieves better signal strength and more network throughput. This can also be verified in practice – surfing the web is much more comfortable on the new model.
||[ 3] 0.0-120.1 sec 5.90 MBytes 412 Kbits/sec
||[ 3] 0.0-124.9 sec 20.6 MBytes 1.38 Mbits/sec
||100 packets transmitted, 88 received, 12% packet loss rtt min/avg/max/mdev = 1.872/11.935/87.561/10.758 ms
||100 packets transmitted, 84 received, 16% packet loss rtt min/avg/max/mdev = 1.728/14.319/151.091/23.329 ms
The inclusion of gigabit ethernet raised quite a few eyebrows: after all, the actual SOC is not able to provide more than about 480 Mbits of total bandwidth to all of the peripheral devices. In practice, this limitation shows up doing iperf runs:
0.0-120.0 sec 4.44 GBytes 318 Mbits/sec