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Diodes part 2: Homemade aluminium diodes
We're back in the lab trying some new combinations and methods to make diodes. This time: aluminium and wet electrolytes. Getting closer to the idea of just being able to 'dab' diodes onto PCBs, but not quite there yet.
BMP280 and ESP8266
The BMP280 is the next generation sensor from Bosch and follows its predecessors BMP085 - BMP180. Price for it is now under $2 with free shipping.
Key parameters
Pressure range 300 … 1100 hPa (equiv. to +9000…-500 m above/below sea level)
Package 8-pin LGA metal-lid
Footprint : 2.0 × 2.5 mm², height: 0.95 mm
Relative accuracy ±0.12 hPa, equiv. to ±1 m
(950 … 1050hPa @25°C)
Absolute accuracy typ. ±1 hPa (950 ...1050 hPa, 0 ...+40 °C)
Temperature coefficient offset 1.5 Pa/K, equiv. to 12.6 cm/K (25 ... 40°C @900hPa)
Digital interfaces I²C (up to 3.4 MHz) SPI (3 and 4 wire, up to 10 MHz)
Current consumption 2.7µA @ 1 Hz sampling rate
Temperature range -40...
IoT with ESP8266
Ten years anniversary of Openmoko
In 2006 I first visited Taiwan. The reason back then was Sean Moss-Pultz contacting me about a new Linux and Free Software based Phone that he wanted to do at FIC in Taiwan. This later became the Neo1973 and the Openmoko project and finally became part of both Free Software as well as smartphone history.
Ten years later, it might be worth to share a bit of a retrospective.
It was about building a smartphone before Android or the iPhone existed or even were announced. It was about doing things "right" from a Free Software point of view, with FOSS requirements going all the way...
Open Hardware Multi-Voltage USB UART board released
During the past 16 years I have been playing a lot with a variety of embedded devices.
One of the most important tasks for debugging or analyzing embedded devices is usually to get access to the serial console on the UART of the device. That UART is often exposed at whatever logic level the main CPU/SOC/uC is running on. For 5V and 3.3V that is easy, but for ever more and more unusual voltages I always had to build a custom cable or a custom level shifter.
In 2016, I finally couldn't resist any longer and built a multi-voltage USB UART adapter.
This board exposes two UARTs at a user-selectable...
Open Hardware miniPCIe WWAN modem USB breakout board released
There are plenty of cellular modems on the market in the mPCIe form factor.
Playing with such modems is reasonably easy, you can simply insert them in a mPCIe slot of a laptop or an embedded device (soekris, pc-engines or the like).
However, many of those modems actually export interesting signals like digital PCM audio or UART ports on some of the mPCIe pins, both in standard and in non-standard ways. Those signals are inaccessible in those embedded devices or in your laptop.
So I built a small break-out board which performs the basic function of exposing the mPCIe USB signals on a USB mini-B socket, providing power supply to...
ESP8266 adapter module fits LoRa Dorji module
Soldering the Dorji LoRa module is not so easy if you don't have soldering skills. But you can borrow this adapter board ($2.60 per 10pcs) from ESP8266 and its fits very well. Same pads distance, just few modification ( remove components) and a short on the back where the AMS1117 should be and that's it, we have a more practical module to work with. Don't forget to add a curly antenna.
Don't forget to relabel the edges with the Dorji's module values, since the labels will not be visible anymore.
Dorji's LoRa module on ESP8266 adapter plate
ESP8266 adapter plate
Back of ESP8266 adapter plate
IoT with ESP8266
ESP8266-ESP201 Step-by-step Guide
This is a step-by-step guide to ESP8266-ESP201.
1. Buy ESP8266-ESP201 with its hardware development kit from eBay, click here:
The development board is shown in photo below as well. You have a relay, buzzer, switches, LEDs, etc. to play with and test your code and to learn input/output functions of ESP8266:
2. Connect the USB cable between your computer and the development board. 3. Push the power button to check if power led is working and the board shows sign of life. 4. Complete schematic of the development board is as follows:
5. On the PCB near the DIP switch these are the values: · R - should be the RED led from the RGB connected to the IO15 pin....
IoT with ESP8266
LoRa Gateway has new antenna
Finally the new 7dB antenna arrived. Since the new antenna has a 3cm magnetic mount I will try to put it on top of the car for better coverage.
New 868Mhz 7dB LoRa antenna
Specs:
Antenna gain: 7dB
Magnetic mount: 3cm
Cable length: 150 cm
Connector: SMA male
I can connected it to the gateway or to the ESP8266 Lora module from Dorji.com.
IoT with ESP8266
Что будет, если подать в электросеть постоянный ток
Война токов завершилась, и Тесла с Вестингаузом, похоже, победили. Сети постоянного тока сейчас используются кое-где на железной дороге, а также в виде свервысоковольтных линий передачи.
Подавляющее большинство энергосетей работают на переменном токе. Но давайте представим, что вместо переменного напряжения с действующим значением 220 вольт в ваш дом внезапно стали поступать те же 220 В, но постоянного тока.
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Vortrag angemeldet: "Hello world!" vor 25 Jahren
Im Sommer 2007 erreichte mich ein dringender Anruf, dass die Abteilung für Programmiersprachen der TU Braunschweig "aufräumen" würde. So konnte ich "meinen" ehemaligen Abteilungs-Haupt-Server der frühen 90er-Jahre vor der Elektroschrott-Box retten und das Ultrix-DECsystem bis heute rund um die Uhr am Laufen halten. Ich werde zuerst erzählen, welche Rolle die Maschine für unsere Abteilung damals gespielt hat und wie unsere Rechenwelt aussah. Dann werfen wir einen Blick speziell auf die Programmiersprachen, die wir auf dieser Maschine verwendet haben. Welche Sprachen waren vor 25 Jahren "state-of-the-art"? Was davon spielt heute noch eine Rolle?
Martin Neitzel